Molecular analysis across the sequence of mucinous ovarian adenoma, borderline mucinous tumour and invasive mucinous carcinoma demonstrates accumulation of a specific driver alteration at every step. Which alteration is this?

• A KRAS mutation ✓
• B TP53 mutation
• C BRAF V600E mutation
• D ARID1A loss

Explanation

Mucinous ovarian tumours progress through an adenoma to borderline to carcinoma pathway driven by KRAS mutations, which are found in more than half of these lesions at all stages and increase in frequency with advancing atypia. TP53 mutation defines the high-grade serous pathway and is essentially universal there, so option B is wrong. BRAF mutation characterises some low-grade serous tumours, and ARID1A loss characterises clear cell and endometrioid carcinomas arising in endometriosis.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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