Characterization of A Rare Case of Vulvar Epithelioid Sarcoma with local recurrence and metastases

Abstract

Abstract Introduction/Objective Epithelioid sarcoma (ES) is a rare, malignant mesenchymal neoplasm that has a known tendency for local recurrence, regional lymph node involvement, and distant metastases. Two histologic variants have been recognized: classic ES also known as the distal type, and proximal-type ES (PES). The classic ES is common in young adults. It occurs more frequently in the distal upper extremities followed by the distal lower limbs and has a male prevalence of 2:1. Conversely, PES commonly involves deep tissues in the pelvic region, including the genital area. It tends to occur in older patients and follows a more aggressive clinical course. In the female genital tract, PES occurs most frequently in the vulva. The incidence of primary sarcoma of the vulva accounts for 1.5-5% of all malignant tumors, making PES a very rare incidence. Methods/Case Report Here we report a 60-year-old female diagnosed with vulvar epithelioid sarcoma treated with a right radical vulvectomy and bilateral inguinal lymph node dissection in 2008. In 2017, further surgery and adjuvant radiation were given for local recurrence. In 2020, the patient developed left hip pain and was found to have an expansile lytic lesion in the left proximal femur. Extensive resection was performed. Grossly the vulvar lesion was nodular with diffuse hemorrhage, degeneration, and necrosis. Microscopically, the tumor cells had large vesicular nuclei, prominent nucleoli, and abundant eosinophilic cytoplasm. Histologically, the morphology of the tumor cells are similar for the primary vulvar specimen and the bone metastases. Immunohistochemically, the tumor cells are positive for vimentin, GATA, FLI-1, SMA, SMHC, partially positive for CAM5.2, AE1/AE3, CD31, and CD163. Immunohistochemistry was negative for CDX2, CD56, S-100, TTF-1, CK5/6, CK20, P40, mammoglobin, MOC31, ER, CK7, CK903, HMB45, PAX8. A Ki-67 proliferative index was around 30-40%. NGS molecular testing detected a SMARCB1 mutation with loss of exons 1-3 and exons 7-9 supporting the diagnosis of epithelioid sarcoma. Results (if a Case Study enter NA) NA Conclusion In summary, we report a case of PES of the vulva in a 60 year old female. Grossly, the lesion was nodular with histology showing large vesicular nuclei, prominent nucleoli, and abundant eosinophilic cytoplasm. It showed loss of INI1/SMARCB1 nuclear expression. The patient is receiving further adjuvant treatment and shows no new metastases.