Adult Colo-Colonic Intussusception in the Setting of Invasive Mucinous Adenocarcinoma: A Case Report.

BACKGROUND Colonic intussusception is a very rare disease in adults, and if present, is usually manifested by another pathology, such as malignancy. This report describes the diagnosis and treatment of the underlying cause of intussusception, which was spontaneously reduced. CASE REPORT A 39-year-old woman with no significant past medical history presented to St. Joseph's University Medical Center on July 2022 with gradually worsening abdominal pains for 1 year and hematochezia for 3 months. Physical examination was positive for left lower quadrant abdominal tenderness to palpation. A computed tomography scan of the abdomen and pelvis without contrast showed a long segment of intussusception involving the sigmoid colon and rectum, without any noticeable lesions. A repeat computed tomography scan with rectal contrast showed a 2.1×1.1-cm mesenteric mass in the sigmoid colon at the region of the intussusception. The patient was taken for a laparoscopic sigmoid resection with primary anastomosis, showing a 5-cm mass in the sigmoid colon, and surgical pathology confirming neoplastic etiology of intussusception. The patient recovered well after surgery, and was referred for oncological intervention soon afterward. CONCLUSIONS This report displays the importance of the type of imaging modalities with and without contrast to diagnosis and determine underlying causes of intussusception and further guide treatment options.