Endometrial stromal tumor presenting as multiple endometrial polyps with limited infiltration; a novel presentation

Abstract Introduction/Objective The 2020 WHO classifies endometrial stromal tumors into endometrial stromal nodule (ESN), low-grade endometrial stromal sarcoma (LGESS), high-grade endometrial stromal sarcoma, and undifferentiated sarcoma. Minimal irregularity of the interface is allowed in ESN (up to 3 foci of <3 mm). In a small number of cases, the irregular interface exceeds the acceptable criteria for ESN but relatively limited compared to most LGESS. These cases are classified as endometrial stromal tumor with limited infiltration. These tumors may recur, and it is best managed as LGESS. Methods/Case Report We report a case of endometrial stromal tumor in a 42-year-old female who presented with abnormal vaginal bleeding. Imaging showed multiple fibroids. She underwent total abdominal hysterectomy and bilateral salpingectomy. On gross examination three endometrial polyps with sharp demarcation from the adjacent myometrium were identified (largest 4 cm). Histology revealed proliferation of uniform small cells with scant cytoplasm and round to oval nuclei with rare mitotic figures in a delicate network of arterioles. Immunostains showed positive staining for CD10 and estrogen receptor while negative for Caldesmon. These polyps were mainly confined to the endometrium with only small foci of irregular border with the myometrium. No vascular invasion, high grade cytologic atypia or necrosis were seen. The tumor showed JAZF1-SUZ12 gene fusion. This case was diagnosed as an endometrial stromal tumor with limited infiltration. Results (if a Case Study enter NA) NA Conclusion In conclusion, endometrial stromal tumors are commonly submucosal or intramural, we report a rare case that presented as multiple endometrial polyps, with very limited myometrium infiltration. To our knowledge, no cases have been reported so far. It is essential to be cognizant of this entity when dealing with polypoid lesions of the endometrium, they may recur and should be managed as LGESS.