A 52-year-old woman presents with postmenopausal bleeding. Imaging reveals a solid left ovarian mass. Histology shows cells arranged in a nested pattern with longitudinal nuclear grooves (coffee-bean nuclei). Which immunohistochemical marker is most useful in confirming this diagnosis?
- A Inhibin ✓
- B CD117 (c-KIT)
- C EMA (epithelial membrane antigen)
- D Chromogranin
Correct answer: A. Inhibin
Explanation
The clinical picture describes an adult granulosa cell tumor: postmenopausal bleeding, solid ovarian mass, and characteristic coffee-bean nuclei with longitudinal grooves. Granulosa cell tumors are sex cord-stromal tumors that stain positively for inhibin and calretinin. CD117 is positive in dysgerminoma. EMA is epithelial and would be negative in stromal tumors.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.