In situ carcinoma of the pancreas.

Two cases of pre-invasive in situ carcinoma of the pancreas treated by surgery are reported. In each case the resection was carried out because of the probable diagnosis of invasive carcinoma of the pancreas. In situ carcinoma of the pancreas is not included in standard clinical classifications of pancreatic cancer. This is an important omission because of the prognostic implications of this diagnosis, and because of the difficulties in interpreting fine needle aspiration cytology or histology on needle biopsy in such cases.