[A Case of Obstructing Rectal Cancer with Obstructive Colitis Resected after Neoadjuvant Chemotherapy to Avoid Anastomotic Leakage].

A 61-year-old male was referred to our department after decompression of the transanal ileus tube due to a rectal cancer obstruction. Colonoscopy revealed a circumferential type 2 tumor, 4 cm from the anal verge. The tumor was diagnosed as rectal cancer tub1-2, Group 5 on biopsy analysis. Longitudinal ulcers descending to the sigmoid colon were present and obstructive colitis was suspected. Enhanced computed tomography showed wall thickness in the Ra, Rb rectum and swelling of the mesorectum lymph node, but distant metastases were not identified. We diagnosed the patient with Ra, Rb rectal cancer cT4aN1aM0, cStage Ⅲb. Because of the risk of anastomotic leakage with obstructive colitis, we planned neoadjuvant chemotherapy(SOX therapy)after laparoscopic transverse colostomy. After neoadjuvant chemotherapy, colonoscopy revealed improvements in the obstructive colitis. The tumor was reduced in size and the chemotherapy appeared effective. We performed laparoscopic rectal super low anterior resection with resection of the D3 lymph node. Histopathological examination revealed tub1, ypT3, ypN0, and the chemotherapeutic outcome was rated as Grade 1a. The final diagnosis was Ra, Rb rectal cancer with ypT3ypN0M0, ypStage Ⅱa.