A 56-year-old woman came to the emergency department presenting with colicky pain in the right iliac fossa of 48-h progression that radiated to the right hypochondrium and the epigastrium, associated with diarrhea. She had undergone gastrointestinal evaluation due to complaints of similar episodes over the past 5 months. Abdominal ultrasound image was normal and bowel transit showed a filling defect located in the cecum, suggestive of a tumor (fig. 1). Abdominal examination revealed pain in the right iliac fossa and the epigastrium, with no signs of peritoneal irritation or increased bowel sounds. There were no important alterations in the laboratory tests. Abdominal CAT scans identified a large mass situated in the middle third of the transverse colon with interposition of the proximal ileum inside the ascending-transverse colon suggestive of invagination, with «sausage-shaped» mass or «target sign» images (figs. 2 and 3), and bowel segments of normal caliber. Urgent surgery was indicated, and radical oncologic right hemicolectomy was performed (fig. 4). The anatomopathologic study of the surgical specimen reported poorly differentiated pT1N0 adenocarcinoma of the cecum.

Figure 1.

Bowel transit: filling defect in the cecum suggestive of the presence of a tumor (black arrow).

Figure 2.

Coronal view of the abdominal CAT scan: invagination of the ileum (thick arrow) in the transverse colon (thin arrow). «Sausage-shaped» mass.

Figure 3.

Axial view of the abdominal CAT scan: invagination of the ileum (thin arrow) in the transverse colon (thick arrow). «Target sign» image.

Figure 4.

Specimen from the right hemicolectomy, with the cecum occupied by the tumor that retracted the ileum and produced the invagination.