Fibroadenoma of ectopic breast tissue masquerading as an axillary lipoma

Fibroadenoma of the breast is the most common benign breast condition found in up to 33% of women aged 35-50. Clinically, these are firm, mobile growths within the breast measuring 1-2 cm. The differential diagnosis include cysts, tubular adenoma and phyllodes tumors. The American College of Obstetricians and Gynecologists (ACOG) notes that fibroadenoma of the breast is associated with an elevated risk factor of 1.76 for future breast cancer. The clinician can differentiate between these growths using mammography and ultrasound.