A spontaneous metastasizing exocrine adenocarcinoma of the pancreas in the rat.

A naturally occurring adenocarcinoma of the exocrine pancreas was found in a male, 12-month-old rat. The tumor was found in the mesentery adjacent to the stomach. It consisted of highly anaplastic cells in combination with large strands of collagenous connective tissue indicating desmoplastic properties. Local metastases were found in the mesentery. Distant metastases were seen in the heart, lungs, mediastinal lymph nodes, liver, spleen, both kidneys, one adrenal, one testis and the sternum. This is the first reported tumor of the exocrine portion of the pancreas in which zymogen granules were demonstrated and multiple distant metastases were found in a rat.