A 52-year-old woman undergoes hysterectomy for a uterine mass. Histology shows a tumor composed of interlacing fascicles of spindle cells with eosinophilic cytoplasm, marked nuclear atypia, coagulative tumor cell necrosis, and 15 mitoses per 10 HPF. Tumor cells are desmin and SMA positive. Which is the diagnosis?
- A Leiomyoma with bizarre nuclei
- B Leiomyosarcoma ✓
- C Endometrial stromal sarcoma
- D Adenosarcoma
Correct answer: B. Leiomyosarcoma
Explanation
Leiomyosarcoma is diagnosed when two of three features are present: moderate-to-severe nuclear atypia, mitotic count ≥10/10 HPF, and coagulative tumor cell necrosis. This case has all three. Leiomyoma with bizarre nuclei has atypical nuclei but low mitotic count and lacks tumor cell necrosis. Endometrial stromal sarcoma shows spiral arteriole-like vessels, is CD10 positive and desmin negative. Adenosarcoma has benign glands within a malignant stroma.
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.