Pediatric colonic adenocarcinoma: A deceptive case of gastroenteritis and constipation

Adenocarcinoma of the colon is a rare diagnosis in pediatric patients. We present a previously healthy 15‐year‐old female who began experiencing escalating colicky abdominal pain and associated vomiting over 2 weeks in the setting of presumed acute gastroenteritis. A computed tomography scan revealed an obstruction in her descending colon. A multidisciplinary decision was made to perform a colonoscopy upon which a large, circumferential, friable lesion was discovered 40 cm from the anus. A colon decompression catheter was successfully inserted following CRE Balloon dilation to 13.5 mm beyond the mass, resulting in a significant discharge of fluid and gas. The patient underwent hemicolectomy with mass resection and colostomy. Biopsies confirmed poorly differentiated adenocarcinoma with “napkin‐ring” morphology and positive lymph node metastasis with extranodal extension.