Intussusception, defined as the invagination of one intestinal segment into another, is common in children but rare in adults. Unlike pediatric cases, adult intussusception is usually associated with an underlying structural lesion, frequently malignant, and often requires surgical management. This case highlights the diagnostic and therapeutic challenges of adult intussusception in the emergency setting.

We report the case of a 73-year-old man admitted for ileocolic intussusception. Contrast-enhanced abdominal computed tomography revealed an ileocolic intussusception associated with suspicious thickening of the colonic wall. Intraoperative exploration confirmed the intussusception and revealed a palpable mass in the right transverse colon. An oncologic right colectomy with ileo-transverse anastomosis was performed. The postoperative course was uneventful, and the patient was discharged on postoperative day 5. Histopathological examination confirmed a T3N0 colonic adenocarcinoma.

Adult intussusception is a rare condition that is frequently associated with an underlying malignancy, particularly in ileocolic forms. Computed tomography plays a key role in establishing the preoperative diagnosis and guiding surgical management. Due to the high risk of malignancy, oncologic resection should be advocated without prior reduction. Primary open surgery may be preferred in cases with suspected malignancy, extensive adhesions, or compromised bowel.

Given the high proportion of malignant lesions among adult patients, oncologic resection should be advocated over reduction, particularly in colonic and ileocolic forms.