Intussusception secondary to signet ring cell adenocarcinoma in adolescent.

Despite the overall decrease in incidence and mortality rates for older adults, colorectal cancer in young adults is increasing. We present a case of a 15-year-old male who presented with 1.5 weeks of intermittent, sharp, severe right-sided abdominal pain. Abdominal radiograph demonstrated an air-fluid level within the right hemiabdomen. Computed tomography demonstrated marked wall thickening and a mass at the junction of the ascending colon and hepatic flexure causing obliteration of the lumen with a fluid-filled, dilated ascending colon. Follow-up ultrasonography demonstrated a 5.9 × 3.9 cm targetoid lesion in the right upper quadrant concerning for intussusception. Contrast enema revealed failure of contrast filling beyond the hepatic flexure due to a lobulated central filling defect surrounded by a claw-like contrast extension. Pathology of the polypoid lesion revealed poorly differentiated signet ring cell adenocarcinoma of the colon at the hepatic flexure. Despite its rarity, this case elucidates the need to consider colorectal carcinoma in adolescent and young adult patients who present with recurrent abdominal signs and symptoms.