Concurrent small bowel gastrointestinal stromal tumor and colonic adenocarcinoma in an elderly patient: a case report

We report here the case of a 68-years-old man with synchronous small bowel gastrointestinal stromal tumor (GIST) and colonic adenocarcinoma, an occurrence reported infrequently in the literature. The patient was found to have these 2 separate malignancies while undergoing surgical evaluation for constipation, abdominal pain and rectal bleeding. Contrast-enhanced CT and colonoscopy diagnostic evaluations revealed a mass in the colon causing near obstruction. The surgical management included subtotal colectomy for the colonic adenocarcinoma and resection of the small bowel GIST. Histopathologic examination confirmed a spindle cell GIST (low grade (G1)) and a well-differentiated colonic adenocarcinoma. This case highlights the need for careful and comprehensive evaluation for synchronous malignancies, particularly so in geriatric patients and potential pathogenic mechanisms for multiple primary tumors and respective management approaches. Optimal outcomes with resection require long-term follow-up, including radiologic surveillance and adjuvant therapy.