Benign gastric neuroendocrine tumors in three snow leopards (Panthera uncia).

Neuroendocrine tumors are relatively rare neoplasms arising from neuroendocrine cells that are distributed throughout the body and are predominant in the gastrointestinal tract. This report describes benign, well-differentiated gastric neuroendocrine tumors in three captive snow leopards (Panthera uncia). All tumors were well circumscribed, were within the gastric mucosa or submucosa, and had histologic and immunohistochemical features of neuroendocrine tumors. Histologic features included packeted cuboidal to columnar epithelial cells that were arranged in palisades or pseudorosettes and contained finely granular cellular cytoplasm with centrally placed, round nuclei. Cytoplasmic granules of neoplastic cells strongly expressed chromogranin A, variably expressed neuron-specific enolase, and did not express synaptophysin or gastrin. Each leopard died or was euthanatized for reasons unrelated to its tumor.