A 32-year-old woman has breast biopsy for a palpable mass showing columnar cell change with flat epithelial atypia (FEA). Molecular profiling demonstrates loss of 16q and gain of 1q. FEA is considered a precursor of which breast carcinoma subtype?
- A Triple-negative (basal-like) breast carcinoma
- B Luminal A / low-grade ER-positive invasive carcinoma (tubular, mucinous, classic lobular) ✓
- C HER2-amplified breast carcinoma
- D High-grade ductal carcinoma in situ (HER2+/ER-)
Explanation
Flat epithelial atypia (FEA) belongs to the 'low-grade neoplasia pathway' of breast carcinoma. The hallmark molecular alterations — loss of 16q and gain of 1q — are shared with low-grade DCIS, lobular neoplasia (ALH/LCIS), tubular carcinoma, and classic lobular carcinoma, all of which are ER-positive, HER2-negative, low-grade lesions. This molecular signature places FEA at the earliest end of the low-grade pathway, progressing through low-grade DCIS to invasive luminal A carcinoma. Triple-negative carcinomas arise via a distinct pathway with TP53 mutations and BRCA1 dysfunction; HER2-amplified tumors have 17q amplification as a driver.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.