Presentation: 40 year-old female with abdominal pain and nausea.

Key findings:

• Very large ileocolic intussusception
• follow the small bowel into the intussuception
• Irregular, lobulated mass at the cecal base.
• Appendix is dilated but not inflamed.
• Numerous enlarged ileocolic lymph nodes about the intussusceptum. 

This is a very dramatic case, best understood on the coronal images. With the mass acting as a lead point, the terminal and distal ileum has telescoped into the cecum, ascending colon, and proximal transverse colon, resulting in a very large intussusception.

The thickened wall of the intussuscipiens actually represents two colonic walls folded over on each other.

This image might help you understand what is going on.

Diagnosis: Malignant ileocolic intussusception. Differential includes adenocarcinoma, lymphoma, GIST, and carcinoid. Enlarged ilecolic lymph nodes could be pathologic or reactive.

Management: Surgical consultation.

Operation: Right hemicolectomy, mesenteric lymph node resection, primary anastomosis. 

Pathology:

• Low grade mucinous adenocarcinoma of the cecum invading into the subserosal adipose tissue and appendiceal wall
• All lymph nodes benign