A 16-year-old with primary amenorrhoea has karyotype 45X/46XY and bilateral streak gonads. One gonad is replaced by a 4 cm grey-white mass showing nests of large germ cells admixed with smaller sex cord-derived cells and eosinophilic basement membrane-like deposits. What is this tumour called?
- A Sex cord tumour with annular tubules
- B Pure dysgerminoma
- C Gonadoblastoma ✓
- D Gynandroblastoma
Correct answer: C. Gonadoblastoma
Explanation
Gonadoblastoma is a mixed tumour containing both germ cells and sex cord stromal elements, occurring almost exclusively in dysgenetic gonads carrying Y chromosomal material such as 45X/46XY mosaicism. Although itself benign, it acts as an in situ precursor capable of progressing to invasive dysgerminoma, which justifies prophylactic gonadectomy. Pure dysgerminoma lacks the sex cord component, and the other two entities occur in phenotypically normal ovaries.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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