Cystic extragastrointestinal stromal tumor masquerading pelvic abscess: A case report

Gastrointestinal stromal tumor (GIST) is the commonest mesenchymal tumor of the gastrointestinal tract, most commonly arising from the stomach but also arising from the omentum, mesentery, and retroperitoneum, which is called extragastrointestinal stromal tumor (EGIST). Rarely may these tumors undergo cystic changes due to central necrosis. In this report, we present a rare case of cystic EGIST, which was misdiagnosed as pelvic abscess by clinical, radiological, and even cytological evaluations. Excision biopsy and immunohistochemical study were required for a correct diagnosis.