Medulloblastomas are malignant primitive neuroectodermal tumors that arise in the posterior fossa in children. Medulloblastomas are the most common malignant 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 in children. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with medulloblastoma present with symptoms of increased intracranial pressure Intracranial Pressure Idiopathic Intracranial Hypertension and cerebellar signs, which both evolve and worsen over weeks to a few months. Magnetic resonance imaging is the imaging modality of choice and typically shows a midline or paramedian cerebellar mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast that enhances with contrast, but histopathological analysis after surgical resection is required for diagnosis. Treatment involves a combination of surgery, 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, and chemotherapy Chemotherapy Osteosarcoma. 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 depends on a variety of factors, but with modern multimodality therapy, roughly 75% of children diagnosed with medulloblastoma survive into adulthood.
Last updated: 3 Jun, 2021
Medulloblastoma is a highly malignant primitive neuroectodermal tumor Tumor Inflammation that develops in the posterior fossa in children. It is an embryonal tumor Tumor Inflammation, arising from neuronal progenitor cells, and generally has a poor 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.
Categories | Specific tumors |
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Neuroepithelial tumors in the CNS |
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Meningeal tumors |
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Sellar region tumors |
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Primary CNS lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum | Primary CNS lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum |
Metastasis Metastasis The transfer of a neoplasm from one organ or part of the body to another remote from the primary site. Grading, Staging, and Metastasis to the 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 (5x more common than primary 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) | Most commonly arising from: |
Peripheral tumors |
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The WHO has developed both genetic and histologic classifications for medulloblastomas.
Medulloblastomas typically arise in the cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy, so patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship typically present with cerebellar symptoms and—since the most common complication of medulloblastoma is hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage—signs of increased intracranial pressure Intracranial Pressure Idiopathic Intracranial Hypertension ( ICP ICP Normal intracranial pressure (ICP) is defined as < 15 mm Hg, whereas pathologically increased ICP is any pressure ≥ 20 mm Hg. Increased ICP may result from several etiologies, including trauma, intracranial hemorrhage, mass lesions, cerebral edema, increased CSF production, and decreased CSF absorption. Increased Intracranial Pressure (ICP)).
Magnetic resonance imaging is the imaging test of choice. Due to the fact that 20%–25% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship have spinal involvement at presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor, MRI of both the 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 and the 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 should be performed. Findings include:
Head MRI showing a cerebellar medulloblastoma in
sagittal
Sagittal
Computed Tomography (CT) and horizontal views:
Sagittal
Sagittal
Computed Tomography (CT) view shows a midline posterior fossa medulloblastoma with intermediate signal intensity. There is an obstruction to the
flow
Flow
Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls.
Vascular Resistance, Flow, and Mean Arterial Pressure of CSF, marked
hydrocephalus
Hydrocephalus
Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial.
Subarachnoid Hemorrhage, and
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.
Horizontal view shows a homogenous enhancing medulloblastoma arising from the right cerebellar hemisphere with
displacement
Displacement
The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate.
Defense Mechanisms of the vermis.
Cerebrospinal fluid Cerebrospinal Fluid A watery fluid that is continuously produced in the choroid plexus and circulates around the surface of the brain; spinal cord; and in the cerebral ventricles. Ventricular System: Anatomy analysis is important in the evaluation for metastasis Metastasis The transfer of a neoplasm from one organ or part of the body to another remote from the primary site. Grading, Staging, and Metastasis since approximately â…“ of medulloblastomas metastasize through the CSF. These medulloblastomas show:
Diagnosis requires confirmation by histopathologic examination at the time of surgical resection.
Microphotograph of medulloblastoma (H&E, Ă—20):
The image shows a highly cellular
tumor
Tumor
Inflammation composed of rosettes of small round cells, with high
nucleus
Nucleus
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (cell nucleolus). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the endoplasmic reticulum. A cell may contain more than one nucleus.
The Cell: Organelles-cytoplasm ratio.
The standard of care Standard of care The minimum acceptable patient care, based on statutes, court decisions, policies, or professional guidelines. Malpractice for management of medulloblastoma is combined modality therapy, including surgery, chemotherapy Chemotherapy Osteosarcoma, 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.
The following posterior fossa tumors are differential diagnoses for medulloblastoma: