Synchronous occurance of adenocarcinoma and gastrointestinal stromal tumor of the stomach.

Gastric adenocarcinoma is the most common histological type of the gastric tumors that accounts for approximately 95% of primary gastric tumors. Gastrointestinal stromal tumors are the most common mesenchymal tumors of the digestive tract accounting for 1%-3% of primary gastric tumors. However, synchronous gastric adenocarcinoma and gastrointestinal stromal tumor of the stomach is an uncommon entity and rarely reported in the literature (1,2). Herein we report such a case, a 75 year old male who was admitted to our clinic with a six month history of epigastric pain, nausea, dyspeptic symptoms and 10 kg weight loss during the last three months. Abdominal CT scan and Esophagogastroduodenoscopy showed an ulcerative mass in the gastric antrum with an endoscopic biopsy of moderately differantiated adenocarcinoma. The patient underwent exploratory laparotomy for adenocarcinoma followed by subtotal gastrectomy and Billroth II gastrojejunal anastomosis. During gastrectomy a well defined extramural, 1 cm nodular lesion was observed at 4 cm proximal to the neoplasm of the antrum and resected, as well. Histopathological examination of the resected stomach confirmed the presence of a moderately differantiated adenocarcinoma infiltrating the submucosa of the stomach with 2 of the 16 resected lymph nodes contained metastasis (Figure 1a). In addition the secondary lesion was histopathologically confirmed to be a gastrointestinal stromal tumor (Figure 1b). The synchronous finding of epithelial and stromal gastric tumors was described in the literature with various hypotheses. Simple coincidence could be the most obvious explanation. Gene mutations might underlie tumor predisposition, or influenced neighboring stomach tissues by the same carcinogen are other two hypotheses (3,4) . Nevertheless it is certain that further molecular biological studies required in order explaining the synchronous development of these tumors. Surgical exicision is the main treatment for both of them following oncologic principles. The postoperative adjuvant therapy should include chemotherapy for the adenocarcinoma, depending on the pathology report and/or imatinib for the GIST (1). Although synchronous tumors are rarely seen, they should be kept in mind especially in diagnostic GIS endoscopy and surgeries.