Benign Bone Tumors

Overview

Osteoid Osteoid Bones: Development and Ossification osteomas Osteomas A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). Familial Adenomatous Polyposis most often present in young people. Osteoblastomas typically present during the second decade but may occur at any age, while osteomas Osteomas A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). Familial Adenomatous Polyposis are most common in middle-aged adults. Osteochondromas and enchondromas are cartilage-forming tumors. Giant-cell tumors are osteolytic. Fibromas and bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change are other benign Benign Fibroadenoma bone lesions Bone Lesions Multiple Myeloma.

Characteristics of benign Benign Fibroadenoma bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors

• Noncancerous; giant-cell tumors have low metastatic potential and can rarely metastasize to the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy
• May cause pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways 
• Range from static lesions (remain essentially unchanged) to locally aggressive lesions (expand until treated, but are still benign Benign Fibroadenoma)
• Characteristic radiographic features are seen on x-rays X-rays X-rays are high-energy particles of electromagnetic radiation used in the medical field for the generation of anatomical images. X-rays are projected through the body of a patient and onto a film, and this technique is called conventional or projectional radiography. X-rays. 
• Often discovered incidentally
• Osteoid Osteoid Bones: Development and Ossification osteoma:
  • Morphologically and genetically similar to osteoblastoma
  • May be 2 different presentations of the same genetic entity

Epidemiology

• Osteochondromas are the most common type of benign Benign Fibroadenoma bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors: 30%–35%
• Giant-cell tumors: 20%
• Osteoblastomas: 14%
• Osteoid Osteoid Bones: Development and Ossification osteomas Osteomas A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). Familial Adenomatous Polyposis: 12%
• All others: less common

Staging Staging Methods which attempt to express in replicable terms the extent of the neoplasm in the patient. Grading, Staging, and Metastasis and classification

• Staging Staging Methods which attempt to express in replicable terms the extent of the neoplasm in the patient. Grading, Staging, and Metastasis:
  • Latent: asymptomatic; discovered incidentally
  • Active: mild symptoms; continued tumor Tumor Inflammation growth
  • Aggressive: grow rapidly
• Classification:
  • Diaphyseal
  • Metaphyseal
  • Epiphyseal

Osteoid Osteoma (in Children)

Description

• Bone-forming hamartomatous lesion seen in young people
• Ovoid: nidus typically < 1.5 cm
• The nidus is a highly vascularized core formed by active osteoblasts Osteoblasts Bone-forming cells which secrete an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone. Bones: Development and Ossification that produce exceptionally high levels of prostaglandins Prostaglandins A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes. Eicosanoids (particularly PGE2 PGE2 The most common and most biologically active of the mammalian prostaglandins. It exhibits most biological activities characteristic of prostaglandins and has been used extensively as an oxytocic agent. The compound also displays a protective effect on the intestinal mucosa. Fever), which drive the characteristic nocturnal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways.
• Predominantly located in the cortex of metaphysis Metaphysis Bones: Structure and Types and diaphysis Diaphysis The shaft of long bones. Bones: Structure and Types (80%–90%) of long bones Long bones Length greater than width. Bones: Structure and Types
• Locations:
  • Most common:
    • Proximal femur
  • Other locations:
    • Tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy
    • Spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy
    • Other parts of the femur

Epidemiology

• Typically presents during the second decade of life (90% < age 25)
• Affects males 2–3 times more often than females

Clinical features

• Often asymptomatic and discovered incidentally
• When symptomatic, presents with:
  • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
    • Constant, intense 
    • Worse at night
    • Manifests before the lesions are visible on x-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests
  • Swelling Swelling Inflammation
  • Deformity Deformity Examination of the Upper Limbs
  • Pathologic fracture Pathologic Fracture Chondrosarcoma
• Spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy lesions may present with:
  • Limping
  • Scoliosis Scoliosis Scoliosis is a structural alteration of the vertebral column characterized by a lateral spinal curvature of greater than 10 degrees in the coronal plane. Scoliosis can be classified as idiopathic (in most cases) or secondary to underlying conditions. Scoliosis
  • Localized tenderness
  • Restriction of motion
  • Paravertebral muscle spasm

Diagnosis

• X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests or CT:
  • Radiolucent Radiolucent An object of low density that is permeable to X-rays (looks black) X-rays core (nidus) surrounded by sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor
  • Cortical thickening 
  • Diffuse medullary sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor 
  • 25%–40% not seen on x-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests and need CT imaging for visualization
  • MRI not recommended: shows soft-tissue edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema, which may obscure the nidus
• Scintigraphy Scintigraphy Sjögren Syndrome: intense enhancement; accurate in localizing the nidus
• Histology: almost identical to osteoblastoma, osteosarcoma Osteosarcoma Osteosarcoma is a primary malignant tumor of the bone characterized by the production of osteoid or immature bone by the tumor cells. The disease is most common in children and young adults and most frequently affects growth plates of the long bones, although it can involve any bone. Osteosarcoma, and enostosis

Management

• NSAIDs NSAIDS Primary vs Secondary Headaches: effective because the nidus produces high levels of prostaglandins Prostaglandins A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes. Eicosanoids
• If symptoms are tolerable or controlled with NSAIDs NSAIDS Primary vs Secondary Headaches, the lesion may be observed with serial examinations and radiographs every 4–6 months.
• If pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways is unresponsive to NSAIDs NSAIDS Primary vs Secondary Headaches or symptoms are intolerable: surgical resection, radiofrequency ablation Radiofrequency ablation Removal of tissue using heat generated from electrodes delivering an alternating electrical current in the frequency of radio waves. Hepatocellular Carcinoma (HCC) and Liver Metastases, cryoablation Cryoablation Fibroadenoma, or MRI-guided high-intensity focused ultrasound

Osteoma (in Adults)

Description

• Differ from osteoid Osteoid Bones: Development and Ossification osteomas Osteomas A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). Familial Adenomatous Polyposis in that osteomas Osteomas A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). Familial Adenomatous Polyposis are solid, bony growths (as opposed to a radiolucent Radiolucent An object of low density that is permeable to X-rays (looks black) X-rays nidus surrounded by sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor).
• Benign Benign Fibroadenoma, round, bone-forming tumors on the cortical surface of a bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types
• Well-defined and solitary
• Diameter usually < 1 cm
• Arises from osteoblasts Osteoblasts Bone-forming cells which secrete an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone. Bones: Development and Ossification:
  • Compact osteomas Osteomas A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). Familial Adenomatous Polyposis: composed of mature lamellar bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types
  • Spongy osteomas Osteomas A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). Familial Adenomatous Polyposis: composed of trabecular bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types with marrow

Epidemiology

• May develop at any age, but most common in middle-aged individuals
• Occur in men slightly more often than in women 
• Associated with Gardner syndrome Gardner syndrome A variant of adenomatous polyposis coli caused by mutation in the apc gene on chromosome 5. It is characterized by not only the presence of multiple colonic polyposis but also extracolonic adenomatous polyps in the upper gastrointestinal tract; the eye; the skin; the skull; and the facial bones; as well as malignancy in organs other than the GI tract. Familial Adenomatous Polyposis as an extracolonic manifestation of familial adenomatous polyposis Familial Adenomatous Polyposis Familial adenomatous polyposis (FAP) is an autosomal dominant inherited genetic disorder that presents with numerous adenomatous polyps in the colon. Familial adenomatous polyposis is the most common of the polyposis syndromes, which is a group of inherited or acquired conditions characterized by the growth of polyps in the GI tract, associated with other extracolonic features. Familial Adenomatous Polyposis

Clinical presentation

• Usually discovered incidentally; often asymptomatic
• May be symptomatic, causing serious “ mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast effect” symptoms (even though they are considered benign Benign Fibroadenoma)
• Location: may cause the following symptoms:
  • In facial bones, may cause:
    • Disturbances in vision Vision Ophthalmic Exam and hearing
    • Cranial-nerve palsies/ proptosis Proptosis Retinoblastoma
    • Facial asymmetry Asymmetry Examination of the Upper Limbs
  • In cranial bones (especially paranasal sinuses Paranasal Sinuses The 4 pair of paranasal sinuses include the maxillary, ethmoid, sphenoid, and frontal sinuses. The sinuses are a group of air-filled cavities located within the facial and cranial skeleton; all are connected to the main nasal cavity and nasopharynx. Paranasal Sinuses: Anatomy), may cause:
    • Secondary sinus obstruction/congestion
    • Headaches
  • Vertebral column Vertebral column The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy: may cause spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy compression Compression Blunt Chest Trauma
• Radiologic findings on x-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests or CT:
  • Radiodense, well-circumscribed, round to ovoid lesions 
  • Do not penetrate the surrounding soft tissues

Management

• Asymptomatic → no treatment
• Symptomatic tumor Tumor Inflammation growth → surgery

Osteoblastoma

Description

• Bone-forming lesion
• Predominantly cortical tumor Tumor Inflammation
• Larger than osteoid Osteoid Bones: Development and Ossification osteoma (> 2 cm)
• Predominance of metaphyseal over diaphyseal locations
• May be locally aggressive

Epidemiology

• Approximately 14% of benign Benign Fibroadenoma bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors
• Typically presents during the second decade of life, but may occur at any age
• Male-to-female predominance: 2.5 to 1

Clinical features

• Location:
  • Involve the axial Axial Computed Tomography (CT) skeleton
  • Vertebral lesions often involve the posterior elements ( vertebral arch Vertebral arch Vertebral Column: Anatomy).
• Presentation:
  • Insidious, dull pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways; worse at night 
  • Painful scoliosis Scoliosis Scoliosis is a structural alteration of the vertebral column characterized by a lateral spinal curvature of greater than 10 degrees in the coronal plane. Scoliosis can be classified as idiopathic (in most cases) or secondary to underlying conditions. Scoliosis if vertebral lesion present
  • Neurologic symptoms if spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy compression Compression Blunt Chest Trauma present

Diagnosis

• X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests:
  • Predominantly lytic lesions Lytic lesions Multiple Myeloma with a rim or perifocal sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor
  • May have internal calcification or “bubbly” appearance
  • Majority of individuals will have rapid cortical expansion:
    • Sometimes cortical destruction
    • Approximately 50% have surrounding sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor or periostitis Periostitis Inflammation of the periosteum. The condition is generally chronic, and is marked by tenderness and swelling of the bone and an aching pain. Acute periostitis is due to infection, is characterized by diffuse suppuration, severe pain, and constitutional symptoms, and usually results in necrosis. Reactive Arthritis.
• CT:
  • Lesions demonstrated as lytic, similar to x-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests
  • Internal matrix mineralization Matrix mineralization Bones: Development and Ossification is better seen on CT.
• MRI:
  • Features may overestimate the lesion.
  • Decreased areas of intensity correspond to foci of calcification.
  • Usually highly vascular and enhance significantly with gadolinium Gadolinium An element of the rare earth family of metals. It has the atomic symbol gd, atomic number 64, and atomic weight 157. 25. Its oxide is used in the control rods of some nuclear reactors. Magnetic Resonance Imaging (MRI)
  • It may mimic a malignant neoplasm but rarely extends into the surrounding soft tissues.

Management

• Asymptomatic → no treatment
• Majority not responsive to NSAIDs NSAIDS Primary vs Secondary Headaches
• Surgery:
  • Resection of the nidus for refractory symptoms
  • Curettage and bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types grafting preferred
  • Other options include radiofrequency ablation Radiofrequency ablation Removal of tissue using heat generated from electrodes delivering an alternating electrical current in the frequency of radio waves. Hepatocellular Carcinoma (HCC) and Liver Metastases and cryoablation Cryoablation Fibroadenoma, with radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma reserved for selected unresectable or recurrent cases.
• Follow-up x-rays X-rays X-rays are high-energy particles of electromagnetic radiation used in the medical field for the generation of anatomical images. X-rays are projected through the body of a patient and onto a film, and this technique is called conventional or projectional radiography. X-rays every 4–5 months

Osteochondroma

Description

• Appearance: bony exostosis Exostosis Benign hypertrophy that projects outward from the surface of bone, often containing a cartilaginous component. Yaws, Bejel, and Pinta (spur) with a cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology cap
  • Cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology cap is thick in children (> 2 cm).
  • Thinner in adults (< 1 cm)
• Location:
  • Metaphysis Metaphysis Bones: Structure and Types of long bones Long bones Length greater than width. Bones: Structure and Types adjacent to growth plates Growth Plates The area between the epiphysis and the diaphysis within which bone growth occurs. Osteosarcoma 
  • Approximately 50% occur around the knee–distal femur or proximal tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy.
  • Also seen in the proximal humerus Humerus Bone in humans and primates extending from the shoulder joint to the elbow joint. Arm: Anatomy

Epidemiology

• Most common primary benign Benign Fibroadenoma bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumor Tumor Inflammation:
  • 30% of all benign Benign Fibroadenoma bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors 
  • 9% of all bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors
• Most common in children and adolescents, especially between ages 10 and 15
• Sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria: male > female
• Hereditary multiple osteochondromas: autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance disease characterized by several bone lesions Bone Lesions Multiple Myeloma

Pathophysiology

• EXT1 or EXT2 tumor Tumor Inflammation suppressor gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics mutations impair the synthesis Synthesis Polymerase Chain Reaction (PCR) of heparan sulfate, which normally regulates growth plate signaling (including Indian hedgehog signaling).
• Cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology can herniate through a periosteal defect and continue endochondral ossification Ossification The process of bone formation. Histogenesis of bone including ossification. Bones: Development and Ossification, forming a cartilage-capped outgrowth continuous with the parent bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types’s cortex and medullary cavity Medullary Cavity Ewing Sarcoma.

Clinical presentation

• Usually presents as a slow-growing, painless palpable mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast near the ends of long bones Long bones Length greater than width. Bones: Structure and Types
• May also be asymptomatic
• If symptomatic with pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, the pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways is due to the direct mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast effect on surrounding soft tissue Soft Tissue Soft Tissue Abscess.
• Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways may also result from mechanical compression Compression Blunt Chest Trauma or irritation of adjacent nerves or blood vessels, fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures through the stalk or cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology cap, or new malignant transformation Transformation Change brought about to an organism’s genetic composition by unidirectional transfer (transfection; transduction, genetic; conjugation, genetic, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell’s genome. Bacteriology–related growth after skeletal maturity.

Diagnosis

• Grossly, the lesion has a pedunculated or sessile stalk with a glistening bluish-white hyaline cartilage Hyaline cartilage A type of cartilage characterized by a homogeneous amorphous matrix containing predominantly type II collagen and ground substance. Hyaline cartilage is found in articular cartilage; costal cartilage; laryngeal cartilages; and the nasal septum. Cartilage: Histology cap.
• Histologically, the cap resembles a disorganized growth plate undergoing endochondral ossification Ossification The process of bone formation. Histogenesis of bone including ossification. Bones: Development and Ossification into mature trabecular bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types at its base.
• X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests:
  • Osseous spur that arises from the surface of the cortex.
  • The lesion points away from the joint, and its cortical and medullary spaces are continuous with those of the parent bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types.
  • May be sessile (base > cap) or pedunculated (cap > base)
  • Usually involves the metaphysis Metaphysis Bones: Structure and Types
• MRI:
  • Warranted if concern for adjacent tissue impingement
  • Indicated if potential for surgical resection

Management

• Most cases do not need treatment.
• Symptomatic cases → excision
• When excision is required, it is performed at the base of the stalk.
• Approximately 1% transform into a chondrosarcoma Chondrosarcoma Chondrosarcoma is a malignant bone tumor characterized by the production of a cartilaginous matrix. This bone tumor most commonly affects adults over the age of 50. Chondrosarcoma usually presents with a slowly increasing mass (or swelling) with a dull achy pain. Chondrosarcoma.

Chondroma (Enchondroma)

Description

• A benign Benign Fibroadenoma tumor Tumor Inflammation composed of mature hyaline cartilage Hyaline cartilage A type of cartilage characterized by a homogeneous amorphous matrix containing predominantly type II collagen and ground substance. Hyaline cartilage is found in articular cartilage; costal cartilage; laryngeal cartilages; and the nasal septum. Cartilage: Histology.
• A chondroma within the medullary cavity Medullary Cavity Ewing Sarcoma is an enchondroma; one on the bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types surface is a periosteal chondroma.

Epidemiology

• Usually present between ages 20 and 50
• Affect men and women equally
• Commonly occur in the small bones of the hands and feet, particularly the metacarpals Metacarpals The five cylindrical bones of the metacarpus, articulating with the carpal bones proximally and the phalanges of fingers distally. Wrist Joint: Anatomy and phalanges Phalanges Bones that make up the skeleton of the fingers, consisting of two for the thumb, and three for each of the other fingers. Hand: Anatomy

Pathophysiology

• Most enchondromas are solitary and sporadic Sporadic Selective IgA Deficiency.
• Residual growth plate cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology persists within the medullary cavity Medullary Cavity Ewing Sarcoma instead of ossifying normally and forms a slowly growing, well-circumscribed hyaline cartilage Hyaline cartilage A type of cartilage characterized by a homogeneous amorphous matrix containing predominantly type II collagen and ground substance. Hyaline cartilage is found in articular cartilage; costal cartilage; laryngeal cartilages; and the nasal septum. Cartilage: Histology nodule Nodule Chalazion.
• Calcification within the nodule Nodule Chalazion produces the characteristic popcorn appearance on imaging.
• Enlargement may cause endosteal scalloping Endosteal Scalloping Chondrosarcoma and cortical thinning, weakening the bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types and increasing the risk of pathologic fracture Pathologic Fracture Chondrosarcoma.
• Ollier disease Ollier Disease Chondrosarcoma and Maffucci syndrome Maffucci Syndrome Chondrosarcoma present with multiple enchondromas, linked to somatic mosaic IDH1 or IDH2 mutations.

Clinical presentation

• Most are asymptomatic and discovered incidentally
• Cortical thinning can cause pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways or a pathologic fracture Pathologic Fracture Chondrosarcoma, especially in the fingers.
• Ollier disease Ollier Disease Chondrosarcoma features multiple enchondromas, often distributed asymmetrically or unilaterally, and carries an increased risk of chondrosarcoma Chondrosarcoma Chondrosarcoma is a malignant bone tumor characterized by the production of a cartilaginous matrix. This bone tumor most commonly affects adults over the age of 50. Chondrosarcoma usually presents with a slowly increasing mass (or swelling) with a dull achy pain. Chondrosarcoma
• Maffucci syndrome Maffucci Syndrome Chondrosarcoma features multiple enchondromas and soft tissue Soft Tissue Soft Tissue Abscess spindle cell hemangiomas, with a significantly higher risk of chondrosarcoma Chondrosarcoma Chondrosarcoma is a malignant bone tumor characterized by the production of a cartilaginous matrix. This bone tumor most commonly affects adults over the age of 50. Chondrosarcoma usually presents with a slowly increasing mass (or swelling) with a dull achy pain. Chondrosarcoma and other malignancies (including ovarian and brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification tumors).

Diagnosis

• X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests:
  • A well-circumscribed, centrally located radiolucent Radiolucent An object of low density that is permeable to X-rays (looks black) X-rays lesion within the medullary cavity Medullary Cavity Ewing Sarcoma, often in the metaphysis Metaphysis Bones: Structure and Types
  • Possible popcorn calcifications and endosteal scalloping Endosteal Scalloping Chondrosarcoma
• Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma/histopathology: lobules Lobules Breasts: Anatomy of hypocellular, mature hyaline cartilage Hyaline cartilage A type of cartilage characterized by a homogeneous amorphous matrix containing predominantly type II collagen and ground substance. Hyaline cartilage is found in articular cartilage; costal cartilage; laryngeal cartilages; and the nasal septum. Cartilage: Histology surrounded by normal lamellar bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types

Management

• Asymptomatic lesions → observation with serial X-rays X-rays X-rays are high-energy particles of electromagnetic radiation used in the medical field for the generation of anatomical images. X-rays are projected through the body of a patient and onto a film, and this technique is called conventional or projectional radiography. X-rays to confirm stability
• Symptomatic lesions or lesions associated with fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures → intralesional curettage followed by bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types graft Graft A piece of living tissue that is surgically transplanted Organ Transplantation packing

Giant-Cell Tumor

Description

• Also known as “osteoclastoma”
• Benign Benign Fibroadenoma
• Can be locally aggressive
• Osteolytic
• Classified as an intermediate neoplasm with low metastatic potential
• Most commonly affects the epiphysis Epiphysis The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united. Bones: Structure and Types of long bones Long bones Length greater than width. Bones: Structure and Types (~ 50% occur around the knee)
• The distal femur and proximal tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy are particularly common sites.

Epidemiology

• Peak incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 20–40 years of age
• Rate overall: 1.3 cases per million people per year
  • 15%–20% of all benign Benign Fibroadenoma bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors
  • Approximately 4%–5% of all primary bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors

Clinical presentation

• Localized pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and swelling Swelling Inflammation at the affected site
• Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with movement and ↓ range of motion Range of motion The distance and direction to which a bone joint can be extended. Range of motion is a function of the condition of the joints, muscles, and connective tissues involved. Joint flexibility can be improved through appropriate muscle strength exercises. Examination of the Upper Limbs of nearby joint
• ↑ Risk of pathological fractures

Diagnosis

• X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests:
  • Multicystic osteolytic lesion, giving a multiloculated “soap-bubble” appearance
  • Most often involves the epiphysis Epiphysis The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united. Bones: Structure and Types, and can extend to the adjacent metaphysis Metaphysis Bones: Structure and Types or the subchondral bone Subchondral Bone Osteochondritis Dissecans
• Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma/histopathology:
  • The exact nature of the tumor Tumor Inflammation is not completely understood; its key neoplastic component is the H3F3A-mutant stromal cell.
  • Multinucleated osteoclastic giant cells Giant cells Multinucleated masses produced by the fusion of many cells; often associated with viral infections. In aids, they are induced when the envelope glycoprotein of the HIV virus binds to the CD4 antigen of uninfected neighboring T4 cells. The resulting syncytium leads to cell death and thus may account for the cytopathic effect of the virus. Giant Cell Arteritis will be seen.
  • Receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors activator of nuclear factor kappa-B Nuclear factor kappa-B Ubiquitous, inducible, nuclear transcriptional activator that binds to enhancer elements in many different cell types and is activated by pathogenic stimuli. The NF-kappa B complex is a heterodimer composed of two DNA-binding subunits: NF-kappa B1 and relA. MALT Lymphoma ligand ( RANKL RANKL A tumor necrosis factor receptor family member that is specific for rank ligand and plays a role in bone homeostasis by regulating osteoclastogenesis. It is also expressed on dendritic cells where it plays a role in regulating dendritic cell survival. Signaling by the activated receptor occurs through its association with tnf receptor-associated factors. Paget Disease of Bone)–expressing cells:
    • Also known as “osteoclast differentiation factor”
    • Highly expressed by the stromal cells within giant-cell tumors
    • RANKL RANKL A tumor necrosis factor receptor family member that is specific for rank ligand and plays a role in bone homeostasis by regulating osteoclastogenesis. It is also expressed on dendritic cells where it plays a role in regulating dendritic cell survival. Signaling by the activated receptor occurs through its association with tnf receptor-associated factors. Paget Disease of Bone expression by the stromal cells → recruitment Recruitment Skeletal Muscle Contraction of osteoclastic cells 
    • Testing for the H3F3A mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations, present in over 90% of cases, can help confirm the diagnosis and distinguish this tumor Tumor Inflammation from other giant cell–rich lesions

Management

• Comprehensive histologic sampling is needed to ensure diagnosis.
• Surgery:
  • Curettage and bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types grafting
  • En EN Erythema nodosum is an immune-mediated panniculitis (inflammation of the subcutaneous fat) caused by a type IV (delayed-type) hypersensitivity reaction. It commonly manifests in young women as tender, erythematous nodules on the shins. Erythema Nodosum bloc resection to minimize recurrence rate
  • A local adjuvant Adjuvant Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (freund’s adjuvant, bcg, corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity. Vaccination may be used, often polymethyl methacrylate bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types cement
• Watchful follow-up for recurrence
• Denosumab Denosumab A humanized monoclonal antibody and an inhibitor of the rank ligand, which regulates osteoclast differentiation and bone remodeling. It is used as a bone density conservation agent in the treatment of osteoporosis. Other Antiresorptive Drugs, a RANKL RANKL A tumor necrosis factor receptor family member that is specific for rank ligand and plays a role in bone homeostasis by regulating osteoclastogenesis. It is also expressed on dendritic cells where it plays a role in regulating dendritic cell survival. Signaling by the activated receptor occurs through its association with tnf receptor-associated factors. Paget Disease of Bone inhibitor, is an option for unresectable or metastatic disease or as neoadjuvant treatment to shrink a tumor Tumor Inflammation before surgery.

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

• Typically benign Benign Fibroadenoma; rare risk of malignant degeneration ↑ with age (approximately 4%)
• Tendency for significant bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types destruction and local recurrence

Differential Diagnosis

• Osteosarcoma Osteosarcoma Osteosarcoma is a primary malignant tumor of the bone characterized by the production of osteoid or immature bone by the tumor cells. The disease is most common in children and young adults and most frequently affects growth plates of the long bones, although it can involve any bone. Osteosarcoma: primary malignant tumor Tumor Inflammation of the bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types characterized by the production of osteoid Osteoid Bones: Development and Ossification or immature bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types by the tumor Tumor Inflammation cells. Osteosarcoma Osteosarcoma Osteosarcoma is a primary malignant tumor of the bone characterized by the production of osteoid or immature bone by the tumor cells. The disease is most common in children and young adults and most frequently affects growth plates of the long bones, although it can involve any bone. Osteosarcoma is most common in children and young adults, and it presents with pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and swelling Swelling Inflammation, sometimes with a palpable mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast, or as a pathologic fracture Pathologic Fracture Chondrosarcoma. Diagnosis is established with imaging studies and biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Management involves systemic chemotherapy Chemotherapy Osteosarcoma and surgical resection. 
• Ewing sarcoma Ewing Sarcoma Ewing sarcoma (ES) is a primary bone malignancy derived from primitive round cells affecting primarily children and teenagers. Ewing sarcoma commonly presents with a painful mass, swelling, and pathologic bone fractures. Ewing Sarcoma: primary bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types malignancy Malignancy Hemothorax derived from primitive round cells. Ewing sarcoma Ewing Sarcoma Ewing sarcoma (ES) is a primary bone malignancy derived from primitive round cells affecting primarily children and teenagers. Ewing sarcoma commonly presents with a painful mass, swelling, and pathologic bone fractures. Ewing Sarcoma affects primarily children and teenagers and commonly presents with a painful mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast, swelling Swelling Inflammation, and pathologic bone fractures Bone fractures Breaks in bones. Bones: Remodeling and Healing. Diagnosis is established with imaging and biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Treatment involves systemic chemotherapy Chemotherapy Osteosarcoma and local control of the tumor Tumor Inflammation with surgical resection or radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma. With proper treatment, the overall 5-year survival is over 70%.
• Chondrosarcoma Chondrosarcoma Chondrosarcoma is a malignant bone tumor characterized by the production of a cartilaginous matrix. This bone tumor most commonly affects adults over the age of 50. Chondrosarcoma usually presents with a slowly increasing mass (or swelling) with a dull achy pain. Chondrosarcoma: malignant bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumor Tumor Inflammation characterized by the production of a cartilaginous matrix. Chondrosarcoma Chondrosarcoma Chondrosarcoma is a malignant bone tumor characterized by the production of a cartilaginous matrix. This bone tumor most commonly affects adults over the age of 50. Chondrosarcoma usually presents with a slowly increasing mass (or swelling) with a dull achy pain. Chondrosarcoma usually presents with a slowly increasing mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast or swelling Swelling Inflammation and dull, aching pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways. Depending on the location, the condition may also be associated with symptoms of nerve compression Nerve Compression Brachial Plexus Injuries. The diagnosis is established on the basis of characteristics found on imaging and tissue biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma results. The mainstay of treatment is surgical excision.
• Multiple myeloma: malignant condition of plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products cells (activated B lymphocytes B lymphocytes Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation. B cells: Types and Functions) primarily seen in the elderly. Monoclonal proliferation of plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products cells results in cytokine-driven osteoclastic activity and excessive secretion Secretion Coagulation Studies of IgG IgG The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b. Hypersensitivity Pneumonitis antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions. Diagnosis is established by plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products electrophoresis Electrophoresis An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current. Blotting Techniques and bone marrow Bone marrow The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells. Bone Marrow: Composition and Hematopoiesis biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Some low-risk individuals may remain stable for years without treatment, while others may progress despite treatment. Chemotherapy Chemotherapy Osteosarcoma is indicated for individuals who meet high-risk criteria.
• Craniopharyngiomas: rare squamous epithelial tumors with a solid and/or cystic Cystic Fibrocystic Change structure that arise from the remnants of the Rathke pouch Rathke pouch Pituitary Gland: Anatomy along the pituitary Pituitary A small, unpaired gland situated in the sella turcica. It is connected to the hypothalamus by a short stalk which is called the infundibulum. Hormones: Overview and Types stalk in the suprasellar region. Symptoms of craniopharyngiomas include headaches, nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics, vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia, visual disturbances, endocrine dysfunction, and behavioral issues. Diagnosis is made by imaging and biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Management involves surgical excision and radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma therapy.