A 35-year-old woman undergoes excisional biopsy of a breast mass. Histology shows lobular carcinoma in situ (LCIS). Compared to ductal carcinoma in situ (DCIS), LCIS is characterized by:
- A High nuclear grade, comedo necrosis, and direct progression to invasive ductal carcinoma
- B Loss of E-cadherin expression, multicentric/bilateral occurrence, and serves as a risk marker rather than obligate precursor ✓
- C ER-negative, HER2-positive immunoprofile with high Ki-67
- D Single focus, unilateral, with cribriform or micropapillary architecture
Correct answer: B. Loss of E-cadherin expression, multicentric/bilateral occurrence, and serves as a risk marker rather than obligate precursor
Explanation
LCIS is characterized by loss of E-cadherin (CDH1 mutation/methylation), causing the loss of cell-to-cell adhesion that gives LCIS cells their discohesive, 'single-file' infiltrating pattern (also seen in invasive lobular carcinoma). LCIS is typically multifocal and bilateral (50% bilateral), ER+/PR+, and considered both a risk marker (7-12x increased risk for both breasts) and a non-obligate precursor. DCIS shows nuclear pleomorphism, comedo necrosis, and is more often unicentric. LCIS does not typically form a palpable mass or show calcifications on mammography.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.