Cytological Diagnosis of Gastric Neuroendocrine Carcinoma in a Pet Inland Bearded Dragon (Pogona Vitticeps)

Abstract A 2-year-old, intact female inland bearded dragon (Pogona vitticeps) presented with a history of hyperglycemia and nonspecific gastrointestinal signs including frequent regurgitation and diarrhea. Ultrasound and computed tomography revealed the presence of gastric and hepatic masses. A fine needle aspiration biopsy with cytology of the liver revealed neoplastic epithelial cells, which were present in variably sized, crowded, disorganized clusters, surrounded by abundant, intact, and bare nuclei suggesting a fragile cell population. Nuclear chromatin was stippled without prominent nucleoli and the cytoplasm was lightly basophilic and the cells had a high nuclear:cytoplasmic (N:C) ratio. The cytologic diagnosis was a malignant neoplasm of neuroendocrine origin. The diagnostic imaging (ultrasonography, computed tomography) and cytology of a hepatic mass led to the antemortem diagnosis of gastric neuroendocrine carcinoma (gNEC). The animal was euthanized due to poor prognosis and diagnosis of gNEC was confirmed with histopathology. Immunohistochemical stains were performed for several neuroendocrine markers, but only somatostatin exhibited mild immunoreactivity in this case. Therefore, fine needle aspiration biopsy with cytology should be considered as a minimally invasive, antemortem diagnostic technique for gNEC in bearded dragons.