Nonregenerative immune-mediated anemia associated with a diffuse large B-cell lymphoma in a captive jaguar (Panthera onca )

Systemic histiocytic disorder in a jaguar (Panthera onca)

A 7-year-old captive female jaguar (Panthera onca) was presented with a 7-day history of dyspnoea and weight loss. Clinical examination revealed hepatomegaly and elevated serum alanine aminotransferase activity. Pulmonary ultrasonography revealed comet-tail images and an alveolar pattern was detected on thoracic radiography. Due to the poor prognosis, the jaguar was euthanized after 10 days. At necropsy, the main gross findings were hepatomegaly, splenomegaly and multifocal to coalescent, slightly elevated grey areas in the lungs. Histological examination revealed neoplastic proliferation of pleomorphic histiocytes arranged in cohesive sheets in the lungs, liver, spleen, kidneys and lymph nodes. Neoplastic cells had intense immunolabelling for vimentin and ionized calcium-binding adaptor molecule 1, and were immunonegative for pancytokeratin, E-cadherin, CD20, CD3 and CD79α. These findings were compatible with a systemic histiocytic disorder, distinct from any well-defined histiocytic proliferative disease in domestic animals.

A RETROSPECTIVE STUDY OF NEOPLASIA IN NONDOMESTIC FELIDS IN HUMAN CARE, WITH A COMPARATIVE LITERATURE REVIEW

This retrospective study of neoplasia in nondomestic felids in human care presents the cases diagnosed at Northwest ZooPath (NWZP), Monroe, Washington, from 1998 to 2017 in conjunction with a scoping literature review. The 554 neoplasms identified in 20 species in the NWZP archive were combined with the 984 neoplasms identified in those same species in the published literature. Some of the cases identified in the literature were from the NWZP archive. Based on this review, mammary adenocarcinoma (183/1,483, 12.3%), lymphoma (89/1,483, 6.0%), squamous cell carcinoma (85/1,483, 5.7%), pheochromocytoma (57/1,483, 3.8%), and thyroid adenoma (57/1,483, 3.8%) are the most frequently reported neoplasms in nondomestic felids in human care. Apparent species predilections for neoplasia include mammary adenocarcinoma in tigers, jaguars, lions, and jungle cats; lymphoma in lions and tigers; squamous cell carcinoma in snow leopards; pheochromocytoma in clouded leopards; ovarian adenocarcinoma in jaguars; cholangiocarcinoma in lions and tigers; multiple myeloma in tigers; bronchoalveolar adenocarcinoma in cougars and lions; hemangiosarcoma, hepatocellular carcinoma, and gastrointestinal adenocarcinoma in lions; mesothelioma in clouded leopards, lions, and tigers; myelolipoma and cutaneous mast cell tumor in cheetahs; soft tissue sarcomas in tigers; and transitional cell carcinoma of the urinary bladder in fishing cats.

First-time application of a PCR-based clonality assay in a large cohort of non-domestic felines

Feline lymphoma, one of the most important malignant tumors in domestic cats, is also increasingly diagnosed in non-domestic felines, most notably, African lions (Panthera leo). The gold standard for the diagnosis of lymphoma is histopathological evaluation. As an additional tool, the PCR for antigen receptor gene rearrangement (PARR) has been established. To support the diagnosis on a molecular level, the PCR-based clonality assay is designed to distinguish between reactive and neoplastic lymphocyte populations. In general, PARR primers are used to target complete immunoglobulin heavy chain V-D-J (IGH-VDJ) and T-cell receptor gamma V-J (TRG-VJ) chain gene rearrangements. In this study, we validated the primer sets used in routine diagnostics of domestic cats for the application in non-domestic felines. Clonality testing was used in 41 non-domestic feline species and the results were interpreted in the light of their clinical history and their pathology. In total, clonality could be detected in 8 non-domestic felines (19.4%), including 3 lymphoma cases confirmed by histopathology. These results confirmed the successful application of domestic feline-specific PARR primers in non-domestic feline species. Diagnostic sensitivity and specificity of the clonality assay were 100% and 88%, respectively. Finally, the overall diagnostic accuracy was 89%.