A Large Cystic Variant of Gastro-intestinal Stromal Tumour arising from the Jejunum: A Case Report.

Gastrointestinal stromal tumours (GISTs) represent a mesenchymal neoplasm arising from the interstitial cells of cajal occurring mainly in the gastrointestinal tract. Here, we present a case of a large GIST arising from the jejunum with cystic presentation unlike the usual presentation as a solid mass. A 50-year-old male patient came with complaint of a painless mobile lump in abdomen of approximately 25 cm in size which had gradually increased over two years. Clinically mesenteric cyst was suspected. Intra-operatively the mass was a 30x25 cm cyst with approximately 2500 ml serous fluid present inside it arising from the anti-mesenteric border of the jejunum, adherent to the jejunum, appendix and the dome of the bladder. The fluid was aspirated and the mass excised along with resection of the involved jejunal segment and appendectomy was done. Diagnosis was confirmed on immunohistochemistry study. Imatinib Mesylate 400 mg OD was started as adjuvant therapy in view of the high risk of metastasis.