[Case of Laparoscopic Sigmoidectomy for a Patient with Persistent Descending Mesocolon].

A 65-year-old man with bloody stools was diagnosed with sigmoid colon cancer on colonoscopy. A preoperative barium enema and a computed tomography colonography scan showed a medial displacement of his descending colon. The preoperative clinical diagnosis was stage cT1 colon cancer, N0, M0, cStage I . Laparoscopic sigmoidectomy was performed. We found adhesions between the descending colon mesentery and the pelvic wall, and noted that the descending colon was not fused with the retroperitoneum and was shifted to the midline. The patient was diagnosed with persistent descending mesocolon (PDM). PDM is a congenital anomaly of fixation resulting from the failure of the descending colon mesentery to fuse with the parietal peritoneum. Anatomical findings should have been noted during the operation, including the fact that the descending colon artery, sigmoid colon artery, and superior rectal artery often branch radially from the inferior mesenteric artery. It is important to understand the anatomical characteristics of PDM and to improve on existing surgical procedures to ensure safe laparoscopic surgery for these patients.

[A case of recurrent rectal cancer with paraaortic lymph node metastasis treated by FOLFIRI therapy leading to complete response].

A 56-year-old woman was referred to our hospital because of melena. After examinations she was diagnosed with rectal cancer. Anterior resection was performed and the final diagnosis was Stage IIIa. She was treated with adjuvant chemotherapy consisting of UFT/Uzel for one year, followed by UFT alone for one year. Two years after the surgery, abdominal CT suggested solitary paraaortic lymph node metastasis. As the patient denied a surgical treatment, mFOLFOX6 chemotherapy was induced. However, the patient developed a grade 3 allergic side effect, FOLFIRI was administered. Six months after the chemotherapy was started, the paraaortic lymph node metastasis had disappeared. After 50 courses, the case was considered to have achieved a clinical CR which has been maintained now. FOLFIRI was effective for recurrent rectal cancer with paraaortic LN metastasis.