Surgical treatment for rectal cancer with abnormally expanded inferior mesenteric vein resulting from pancreatic arteriovenous malformations.

A 52-year-old Japanese man presented for evaluation and treatment of rectal cancer. Screening computed tomography revealed pancreatic arteriovenous malformations (P-AVMs) and abnormally expanded inferior mesenteric vein (IMV) that resulted from P-AVMs. One-stage surgery for rectal cancer was dangerous so we first performed distal pancreatectomy to cure P-AVM and thus normalize the abnormally expanded IMV. After the operation, the IMV was occluded by the thrombi, and then the IMV became normal. We could perform safely radical laparoscopic surgery for rectal cancer. This is the first case report of P-AVMs combined with rectal cancer.