Ectopic pancreas. A cause of false-positive peritoneal cytology.

A patient with a history of ovarian adenocarcinoma underwent further surgery because malignant cells were reported in peritoneal washings on two separate occasions. Subsequent laparotomy revealed an ectopic pancreas on the jejunum. Review of the peritoneal cytologies confirmed that the cells previously thought to be malignant were in fact consistent with cells detached from the ectopic pancreas.