Concurrent pancreatic exocrine hyperplasia and adenomas in a Eurasian otter with pleuropneumonia and urolithiasis

Abstract

The Eurasian otter (Lutra lutra) is a semi-aquatic mammal classified as near-threatened by the International Union for Conservation of Nature. There have been few reports on their diseases, especially neoplasms. Here we describe exocrine nodular hyperplasia and adenomas in the pancreas, along with suppurative pleuropneumonia and urolithiasis, in an aged captive Eurasian otter. Pancreatic adenomas are rare in animals, and coexistence of adenoma and nodular hyperplasia in the pancreas has not been reported previously in veterinary medicine, to our knowledge.

Keywords: Pasteurella multocida; otters; pancreatic adenoma; pleuropneumonia; urolithiasis.

Figure 1.

Gross lesions in a male Eurasian otter. A. Large amount of blood-tinged and turbid pleural effusion in the thoracic cavity, with exudate loosely attached to the visceral and parietal pleura. The lungs are atelectatic. B. The pancreas is enlarged by pale-beige to white nodules. C. Both kidneys are enlarged with expanded lobes, and the material within the right kidney (on the left) is visible through the thinned renal capsule. D. Sagittal section of both kidneys. Severe cystic changes, enlargement of renal pelvises, and loss of parenchyma with numerous calculi. The right kidney (on the left) is collapsed after the leakage of its internal fluid component.

Figure 2.

Histologic sections of the pancreas from a Eurasian otter. H&E. A. Well-circumscribed unencapsulated nodules of acinar hyperplasia (arrows). B. Acinar hyperplasia (H) is distinguished from the normal pancreatic parenchyma (N) by more crowding of nuclei and elongated tubuloglandular units with increased eosinophilic zymogen granules. C. Some adenomas are well circumscribed by prominent fibrous capsules (arrow), compressing the adjacent pancreatic parenchyma. These nodules are composed of acinar cells and do not include islets of Langerhans. D. The acinar cells in the adenoma are more crowded, are basophilic, and have prominent nucleoli.