A 12-year-old female spayed poodle mix presented to the Cornell University Hospital for Animals (CUHA) Internal Medicine service on referral for evaluation of chronic soft stool and pancreatitis. The work up revealed a mild thrombocytopenia, which progressed to moderate over the next two weeks, and a peri-aortic sublumbar mass. Based on these clinical abnormalities, an immune-mediated thrombocytopenia secondary to neoplasia was prioritized.

A fine needle aspirate (FNA) of the mass with cytologic evaluation was planned but delayed pending improvement of the thrombocytopenia. Following successful medical management, the cytology of the FNA was consistent with a tumor neuroendocrine or endocrine origin. A computed tomography (CT) scan was performed for surgical planning and to check for metastasis. The mass was surgically removed and submitted for histopathology, which revealed a malignant neuroendocrine tumor. Upon further immunohistochemical staining, a diagnosis of extra-adrenal paraganglioma was made. The patient subsequently presented to the CUHA Oncology service and began metronomic chemotherapy with chlorambucil.

This presentation will discuss the diagnosis, pathophysiology, and treatment of paraganglioma.