Small Bowel Adenocarcinoma Arising in an Iatrogenically Created Jejunosigmoid Bypass.

We believe this to be the first case report of jejunosigmoid bypass harboring small bowel adenocarcinoma. The mechanism of malignant degeneration could be similar to that of carcinogenesis of ureterosigmoidostomy that is of historical interest. This case represents an example of why it is imperative for surgeons to be diligent in their preparation and workup of a patient before a complex operation, especially in patients with peculiar or unknown surgical histories.