A 28-year-old woman has a well-circumscribed, mobile, rubbery breast lump that increases in size during pregnancy. Biopsy shows a biphasic tumour with both epithelial (gland-forming) and stromal components, with the stroma being the neoplastic component. This is a:
- A Phyllodes tumour
- B Fibroadenoma ✓
- C Tubular adenoma
- D Sclerosing adenosis
Explanation
Fibroadenoma is the most common benign breast tumour in young women, arising from the terminal duct-lobular unit. It is a biphasic tumour with both fibrous stroma (neoplastic) and epithelial components, forming well-circumscribed, mobile 'breast mouse' lesions that grow during pregnancy and regress post-menopausally under hormonal influence. Phyllodes tumours are also biphasic but show hypercellular leaflike stromal fronds, higher stromal mitoses, and a wider age range; they can be borderline or malignant. Sclerosing adenosis is a non-neoplastic lobular proliferation.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.