A 45-year-old woman has a uterine mass on imaging. Hysterectomy reveals a fleshy, yellow, infiltrative myometrial tumor. Microscopy shows uniform small cells infiltrating in a 'tongue-like' pattern around thick-walled blood vessels. The tumor cells are CD10 positive. Which gene fusion is characteristic of this neoplasm?

• A COL1A1-PDGFB
• B FUS-CHOP (FUS-DDIT3)
• C JAZF1-SUZ12 (JAZF1-JJAZ1) ✓
• D EWSR1-ATF1

Explanation

Low-grade endometrial stromal sarcoma (ESS) characteristically harbors the JAZF1-SUZ12 (formerly JAZF1-JJAZ1) gene fusion from t(7;17)(p15;q21). It shows uniform small cells with a prominent vascular network and tongue-like myometrial infiltration. CD10 positivity supports the diagnosis. FUS-CHOP is seen in myxoid liposarcoma, COL1C1-PDGFB in dermatofibrosarcoma protuberans, and EWSR1-ATF1 in clear cell sarcoma.

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.