Neuroendocrine carcinoma of the nasopharynx in a dog.

Neuroendocrine carcinoma of the nasopharynx was diagnosed in a 9-year-old male Golden Retriever. The mass was identified by computed tomography of the nasal cavity and nasopharyngoscopy, and it was surgically excised. Histologic, cytochemical, and electromicroscopic examination of specimens confirmed the type of tumor. The dog was clincally improved for 150 days but was then reexamined because of respiratory difficulty and poor appetite. Thoracic radiographs revealed multiple nodules in all lung lobes, and ultrasonography revealed a mass in the spleen. The dog died the next day.