Synchronous colorectal adenocarcinoma and gastrointestinal stromal tumor in Meckel's diverticulum; an unusual association

BACKGROUND: Coexistence of gastrointestinal stromal tumor with synchronous or metachronous colorectal cancer represents a phenomenon with increasing number of relative reports in the last 5 years. Synchronous occurence of GISTs with other gastrointestinal tumors of different histogenesis presents a special interest. We herein report a case of GIST in Meckel's diverticulum synchronous with colorectal adenocarcinoma. CASE PRESENTATION: A 69 year old man, presented with abdominal distension and anal bleeding on defecation. Colonoscopy revealed colorectal cancer and a low anterior resection was performed, during which a tumor in Meckel's diverticulum was discovered. Histologic examination revealed GIST in Meckel's diverticulum and a rectosigmoid adenocarcinoma. CONCLUSION: Whenever GIST is encountered, the surgeon should be alert to recognize a possible coexistent tumor with different histological origin. Correct diagnosis of synchronous tumors of different origin is the cornerstone of treatment.