Fibroadenoma – Top USMLE Diseases

Female breasts, made of glandular, adipose, and connective tissue, are hormone-sensitive organs that undergo changes along with the menstrual cycle and during pregnancy. Breasts may be affected by various diseases, in which different imaging methods are important to arrive at the correct diagnosis and management. Mammography is used for breast cancer screening and diagnostic evaluation of various breast-related symptoms. Ultrasonography is rarely used for screening, but it is typically used for diagnostic workup and during procedures (e.g., breast biopsy). MRI of the breasts is used as a supplementary screening tool for those at high risk for developing breast cancer. Additionally, in individuals with breast implants, inconclusive mammographic and/or breast ultrasound findings, and diagnosed breast cancer needing evaluation pretreatment and posttreatment, MRI is an important breast radiologic tool.

Mastitis is inflammation of the breast tissue with or without infection. The most common form of mastitis is associated with lactation in the first few weeks after birth. Non-lactational mastitis includes periductal mastitis and idiopathic granulomatous mastitis (IGM). Lactational mastitis is most commonly caused by Staphylococcus aureus that is introduced into the breast milk during breastfeeding. The etiology of non-lactational mastitis is poorly understood, but periductal mastitis is commonly associated with smoking, and IGM is frequently associated with Corynebacterium. Patients present with edema, erythema, tenderness, and, possibly, a mass in the breast. Diagnosis is usually clinical, although ultrasound, cultures, and biopsy may be required in some cases. Management involves antibiotics, analgesics, drainage of any abscesses, and surgical duct excision for periductal mastitis.

Fibroadenomas are the most common benign tumor of the female breast and the most common breast tumor in adolescent and young women. The tumors are well-circumscribed, mobile, and unencapsulated, with a rubbery or firm consistency. Fibroadenomas are hormonally responsive, so they may increase in size during pregnancy and usually regress after menopause. Histologically, fibroadenomas are composed of a biphasic proliferation of both glandular and stromal elements. Fibroadenomas are associated with a slightly increased risk of carcinoma, with a somewhat higher risk if so-called “complex” features are present. Diagnosis is based on physical findings and ultrasonography. Management is based on regular checkups to monitor growth.