Gastrointestinal stromal tumors (GISTs) are uncommon when compared to all gastrointestinal neoplasms but are the most common (80 - 85%) and specific mesenchymal tumors of the gastrointestinal tract. GISTs often present solid tumors and are rarely predominantly cystic. This report presents a case of a large exophytic cystic GIST in 61-year-old woman who was referred to specialized oncologic clinic from an unspecialized hospital with a suspicion of huge pancreatic cystic lesion based on CT imaging. A multidisciplinary meeting including gastrointestinal surgical oncologists, endoscopists and radiologists was held before operation and gastric GIST with cystic appearance was highly doubtful as a definite preoperative clinicoradiologic diagnosis. Radiologically other cystic lesions were less doubtful. Taking into consideration the possible clinicoradiological diagnosis surgery was planned. At laparotomy a large exophytic cystic mass was found to be attached by a thin (3.0 cm in diameter) stalk to the greater curvature of the stomach at the level of its upper third. No infiltration into the surrounding structures was observed. The cyst was very mobile and did not attach to adjacent anatomical structures by adhesions. The lowermost pole of the lesion was at the level lower than umbilicus. The size of the mass was 18 × 17 × 10 cm. Wedge resection of the greater curvature of the stomach along with the cystic mass and the adherent greater omentum was performed. Pathology confirmed spindle cell tumor. Mitotic index was ≤ 5/50 HPFs and the tumor cells demonstrated positivity for CD117 on immunohistochemical staining. The histological features together with the immunohistochemical profile of the tumor cells were consistent with the GISTs. The tumor was accepted as GIST of the stomach with high risk of recurrence according to the generally accepted classifications. Patient was administrated imatinib for 12 months and during the 16 months’ postoperative period no local recurrence or metastases were detected.
Citation: Ramiz B Bayramov., et al. “Giant GIST of the Stomach Masquerading Gigantic Cyst Located in the Upper Part of the Peritoneal Cavity”. Acta Scientific Gastrointestinal Disorders 4.6 (2021): 23-27.