Extragastrointestinal stromal tumor of lesser omentum: a challenging radiological and histological diagnosis.

Extragastrointestinal stromal tumors (EGISTs) are a rare subgroup of gastrointestinal stromal tumors (GISTs), arising from outside the walls of gastrointestinal tubular organs. We report a case of an EGIST of the lesser omentum that represented a diagnostic challenge. Due to its atypical radiologic findings, it was preoperatively mistaken for pedunculated hepatic hemangioma. Histopathologically, it showed epithelioid structure and c-kit negative, very uncommon for GIST. Only a few cases of EGISTs have been previously reported. We discuss imaging and histological features, emphasizing potential pitfalls.