FNAC of a parotid mass in a 45-year-old woman shows a mixture of epidermoid cells, intermediate cells and mucin-producing cells. Cytogenetic analysis demonstrates a translocation involving chromosomes 11 and 19. Which molecular alteration is characteristic of this tumour?
- A PAX8-PPAR gamma fusion
- B CRTC1-MAML2 fusion ✓
- C EWS-FLI1 fusion
- D MYB-NFIB fusion
Correct answer: B. CRTC1-MAML2 fusion
Explanation
The cytology describes mucoepidermoid carcinoma, the most common malignant salivary gland tumour. A majority of cases carry a t(11;19)(q21;p13) translocation producing the CRTC1-MAML2 (formerly MECT1-MAML2) fusion gene, which drives NOTCH-related oncogenic signalling. MYB-NFIB characterises adenoid cystic carcinoma, EWS-FLI1 is seen in Ewing sarcoma, and PAX8-PPAR gamma occurs in follicular thyroid carcinoma.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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