Which markers are in the IHC panel for primary ovarian stromal sarcomas?

• A. Cyclin D1, BCOR, CD10
• B. Inhibin, SF-1, FOXL2
• C. SALL4, LIN26, HCG
• D. PTH, chromogranin

Answer: (A)

Ovarian stromal sarcomas arise from the mesenchymal stroma of the ovary, so their immunophenotype favors markers of mesenchymal/stromal differentiation rather than germ cell or sex cord–stromal lineages. Cyclin D1 and CD10 are markers that can be expressed in mesenchymal ovarian tumors and help support a stromal/sarcoma diagnosis, while BCOR positivity adds support for BCOR-rearranged sarcomas, a subset seen in ovarian stromal neoplasms. In contrast, markers like Inhibin, SF-1, and FOXL2 point to sex cord–stromal tumors (such as granulosa or Sertoli-Leydig), and SALL4, LIN28 (LIN26), and HCG indicate germ cell tumors; PTH and chromogranin are not typical for ovarian stromal sarcomas. Putting it together, the panel with Cyclin D1, BCOR, and CD10 best fits primary ovarian stromal sarcomas.