Pax5 and CD3 immunophenotyping of lymphoma in 2 central bearded dragons

Abstract

Two central bearded dragons ( Pogona vitticeps), a 3-y-old male and a 5-y-old female, were diagnosed with different manifestations of lymphoma at the Kansas State Veterinary Diagnostic Laboratory between 2019 and 2020. The 3-y-old male was presented for postmortem evaluation and was in poor body condition. Microscopically, nearly all examined organs contained variable numbers of neoplastic round cells. Neoplastic cells in the stomach and liver had moderate immunoreactivity to CD3 consistent with multicentric T-cell lymphoma, and non-neoplastic lymphocytes infiltrating the stomach mass had strong immunoreactivity to Pax5. The 5-y-old female had an ulcerated oral mass located in the right lingual gingiva submitted as an excisional biopsy. Microscopically, the mass was composed of large numbers of neoplastic round cells in the epithelium and connective tissue that were strongly and diffusely positive for CD3 and frequently positive for Pax5, consistent with a dual-positive, localized, epitheliotropic T-cell lymphoma. Neoplastic and non-neoplastic lymphocytes did not stain with CD20 or CD79a. Neoplasms are increasingly reported as a cause of morbidity and mortality in reptiles. Our 2 cases illustrate various presentations of T-cell lymphoma and the effectiveness of CD3 and Pax5 immunohistochemistry in bearded dragons.

Concurrent Diffuse B-cell Lymphoma and Paraganglioma in a Red-tailed Boa (Boa constrictor constrictor) with Inclusion Body Disease

“…Pax5, known as B-cell specific activator protein, is a reliable marker to diagnose canine (Ramos-Vara and Borst, 2017), feline (Ramos-Vara and Borst, 2017), and human (Desouki et al ., 2010) B-cell lymphoma. More recently, Pax5 was used to diagnose an anaplastic B-cell lymphoma in a bald eagle ( Haliaeetus leucocephalus ) (Visser et al ., 2018) and a bi-phenotypic lymphoma in a central bearded dragon ( Pogona vitticeps ) (Rooney et al ., 2022). This case demonstrates the efficacy of Pax5 in snakes (Boidae, at least), which allowed an unequivocal diagnosis of B-cell lymphoma.…”

“…Spontaneous lymphoma is reported in snakes, with CD3þ T-cell lymphoma being most common, but this may reflect a previous lack of available B-cell markers (Ossiboff, 2018). Pax5, known as B-cell specific activator protein, is a reliable marker to diagnose canine (Ramos-Vara and Borst, 2017) to diagnose an anaplastic B-cell lymphoma in a bald eagle (Haliaeetus leucocephalus) (Visser et al, 2018) and a bi-phenotypic lymphoma in a central bearded dragon (Pogona vitticeps) (Rooney et al, 2022). This case demonstrates the efficacy of Pax5 in snakes (Boidae, at least), which allowed an unequivocal diagnosis of B-cell lymphoma.…”

Immunohistochemical identification of T and B lymphocytes in formalin-fixed, paraffin-embedded tissues of 53 avian species using commercial antibodies

“…This suggests that the antibody is the most effective for immunohistochemical detection of avian B lymphocytes. Different anti-human PAX5 antibodies have been employed to detect B lymphocytes in mammals and reptiles through IHC [ 4 , 12 , 19 , 47 , 59 ]. Furthermore, in avian species, the mouse anti-human PAX5 antibody (clone 24) has been reported to detect B lymphocytes in 14 species belonging to the order Psittaciformes (parrots) and domestic pigeons [ 14 , 40 ].…”