Coexistence of gastric cancer and gastrointestinal stromal tumor: report of two cases.

Gastrointestinal stromal tumors and adenocancers are distinct neoplasms originating from different cell layers. Though adenocancers constitute the most common type of gastric tumors, synchronous development of a gastrointestinal stromal tumor is extremely rare. Case 1: A 63-year-old male patient underwent a radical total gastrectomy with D2 lymphadenectomy and Rouxen-Y reconstruction. Histopathologic and immunohistochemical examination of the specimen disclosed an advanced stage, intestinal type adenocancer intermixing with a distinct lesion of gastrointestinal stromal tumor. The early postoperative course was uneventful; however, recurrence was seen and he survived only 13 months. Case 2: A 60-year-old male patient underwent a distal subtotal gastrectomy with D2 lymphadenectomy, and reconstruction was provided with Billroth 2 procedure. Intraoperatively, a 0.5 cm vegetating lesion was detected on the gastric body and resected. Histopathologic and immunohistochemical examination disclosed an intestinal type adenocancer, and the incidental lesion was reported as gastrointestinal stromal tumor. His postoperative course was uneventful, and the patient is free of disease after one year. The conditions under which the synchronous tumors develop away from each other or collide are vague. Currently, the stage of the adenocancer and the size and mitotic manner of the gastrointestinal stromal tumors are the leading prognostic factors.