A novel CDKN1A-JAZF1 gene fusion in low-grade endometrial stromal sarcoma arising from endometriosis in abdominal wall cesarean section scar: A case report and literature review

Objective We report a low-grade endometrial stromal sarcoma (ESS) with a novel CDKN1A-JAZF1 fusion gene arising from abdominal wall endometrioma. Case report A 40-year-old woman presented with a 5.5-cm abdominal wall mass juxtaposed to the postoperative scar of two cesarean sections. Histologically, the tumor exhibited obvious tongue-like protrusions into the surrounding tissue, showed spindle cells with multinodular growth pattern that occasionally rotate around small arteries. Immunohistochemically, the tumor cells were positive for CD10, estrogen receptor (ER), progesterone receptor (PR), negatively stained for smooth muscle actin (SMA), CD117, CyclinD1. In addition, a previously undescribed gene fusion between CDNK1A 5′ end of exon 1(NM_000389.5) and JAZF1 3′ end of exon 5 (NM_175,061,3) was reported in this case. Conclusion This report of ESS suggesting that rapidly growing abdominal wall masses without menstruation-related should be promptly evaluated and treated aggressively. In addition, we have expanded the molecular landscape of low-grade ESS.