Computed tomography features of a primary extragastrointestinal stromal tumor of the lesser omentum with spontaneous calcification in a young adult: A case report.

Extra-gastrointestinal stromal tumors (EGISTs) of the lesser omentum are exceedingly rare mesenchymal neoplasms. Their precise preoperative diagnosis is a well-recognized radiological challenge because they frequently mimic exophytic visceral tumors on cross-sectional imaging. A 28-year-old woman presented with a 1-year history of a progressively enlarging epigastric mass. Contrast-enhanced multidetector computed tomography (MDCT) revealed a 9.0 × 9.6 × 12.0 cm heterogeneously enhancing mass. Using multiplanar reformations, the absence of the "claw sign" and the presence of preserved fat planes between the mass and the adjacent stomach and liver accurately localized the tumor to the lesser omentum. This radiologic mapping allowed for an expedited, organ-preserving surgical excision. Histopathological analysis confirmed a CD117-positive EGIST. Spontaneous calcification in an untreated primary EGIST is a rare imaging finding that broadens the differential diagnosis of calcified intra-abdominal masses. This case underscores the vital role of meticulous MDCT evaluation, particularly assessment of tumor-visceral interfaces, in determining the exact anatomical origin and guiding optimal surgical planning to avoid unnecessary visceral resection.