A Case of Rectal Duplication with Cancer

A 74-year-old man was operated as a cancer originated from anal fistula. Macroscopic and microscopic examinations revealed the adenocarcinoma in duplicated rectum which invaded into the proper muscle layer. This case satisfied all of the criterion for the diagnosis of duplication of the alimentary tract proposed by Macleod and Purves in 1970. Cancer of the rectal duplication has been reported fitstly by Fletcher and Waring in 1900. Only a few cases have been reported subsequently. There were 7 cases in the Japanese literatures, 6 cases by Sumikoshi and one case by the author. These 7 cases showed the clinical feature of anal fistula with cancer. The differential diagnosis of fistula cancer from the duplication with cancer appeared to be very difficult preoperatively in any of these cases.