Proximal epithelioid sarcoma of the vulva. A rare neoplasm. A clinicopathological case

Abstract

Epithelioid sarcoma is a rare aggressive soft tissue sarcoma, which can be distal or proximal types. The classic form (distal-type) of epithelioid sarcoma mainly occurs in teenagers and young adults. A rarer form, called large-cell (proximal-type) epithelioid sarcoma, tends to be more aggressive and mainly affects adults. The proximal subtype mostly arises from the proximal pelvis, limbs, and genital tract. We report a case of a 59 -year-old female, presented with a progressively growing mass in the left labia majora. Gynecologic examination revealed a 2 cm mobile and painless mass that was not attached to deep planes. The histological study showed a multinodular tumor was seen comprising sheets of oval to polygonal cells with moderate amount of cytoplasm. Interspersed were larger, rhabdoid cells with abundant eosinophilic cytoplasm and prominent nucleoli. On IHC, the tumor cells showed positivity for EMA and CKAE1/AE3 and do not expressed INI-1 in the nucleus. All tumor cells were negative for S-100 protein and CD34. The histopathological diagnosis was soft tissue of the vulvar region with proximal epithelioid sarcoma. The patient received adjuvant external pelvic radiotherapy and brachytherapy in the vulvar bed. Currently, 3 years after diagnosis, the patient does not present signs of tumor recurrence in her controls. Due to its low incidence, there are no evidence-based diagnostic algorithms or published recommendations for treatment. The prognosis is generally poor. A wide excision with clear margins is imperative with options of post-operative CT/RT in individual cases during a close follow-upbehavior, as seen in our case.