Intussusception due to rectal adenocarcinoma in a young adult: A case report

Figure 1 Colonoscopy showing a huge tumor at the upper rectum. The tumor, measuring 100 mm in diameter, does not show invagination on colonoscopy.

Figure 2 Magnetic resonance imaging showing intussusception caused by a tumor in the pelvis. The upper rectal tumor (asterisk) causes intussusception (arrowheads) as a leading edge.

Figure 3 Specimen resected in en bloc fashion. The tumor is located at the upper rectum, and the margin is negative for cancer. Pathological staging is pStage IIA (T3, N0, M0).

Figure 4 Microscopic findings and immunohistochemistry for deoxyribonucleic acid mismatch repaire proteins (× 200). The tumor is a poorly differentiated adenocarcinoma. Immunohistochemical expression of mutL homolog 1 (MLH1), postmeiotic segregation increased 2 (PMS2), mutS homologue 2 (MSH2) and mutS homologue 6 (MSH6) is retained. HE: Hematoxylin and eosin stain. A: HE; B: MLH1, C: PMS2; D: MSH2, E: MSH6.