Hypercalcemia in Two Amazon Parrots with Malignant Lymphoma

Abstract

Malignant lymphoma is a common malignancy in birds. Paraneoplastic syndromes, which are commonly observed in domestic animals, have not been reported in association with lymphoma in birds. Hypercalcemia and hyperglobulinemia were found on plasma chemistry in two Amazon parrots, which were presented with aspecific symptoms. In both cases radiography and ultrasound demonstrated signs of hepatomegaly, which proved to be due to malignant lymphoma on postmortem examination. The hypercalcemia was found to be most consistent with a paraneoplastic effect of the malignant lymphoma in these birds. The exact origin of the hyperglobulinemia remains unclear.

T-Cell Chronic Lymphocytic Leukemia in a Double Yellow-headed Amazon Parrot (Amazona ochrocephala oratrix)

“…7,9,15,16,18,20,21,28 The bird we describe had an intermittent mild anemia; however, thrombocytopenia was more persistent and progressive, although thrombocytes were judged to be adequate before starting therapy. Likely causes of the anemia included myelophthisis, bone marrow suppression secondary to chemotherapy, and anemia of chronic disease.…”

“…15 There are several case reports in which immunophenotyping was used to diagnose T-cell lymphoid neoplasia in a variety of nonpoultry avian species. [15][16][17][18][19] Likewise, there have been several case reports in which leukemia has been present associated with a lymphoid neoplasm. 9,15,[20][21][22][23][24] Of these reports, only one bird was diagnosed with T-cell CLL, a 32-year-old male green-winged macaw (Ara chloroptera).…”

“…25 Immunophenotyping has been used in many of the case reports on nondomestic avian species with lymphoma but has generally not been validated for use in those species. [16][17][18][19]21,26 For example, B-lymphocyte antigen antibodies (BLA.36) were used to diagnose B-cell neoplasia in 2 umbrella cockatoos (Cacatua alba). 21,26 In another case report of T-cell intestinal lymphosarcoma in a yellow-naped Amazon parrot (Amazona ochrocephala auropalliata), CD79a and BLA.36 expression were not seen in control psittacine-bird splenic tissue or neoplastic tissue, whereas CD3 staining was found in both.…”

Diffuse Intestinal T-cell Lymphosarcoma in a Yellow-Naped Amazon Parrot (Amazona Ochrocephala Auropalliata)

“…Monoclonal gammopathies in mammals are typically associated with a monoclonal line of plasma cells or lymphocytes that produce immunoglobulin or immunoglobulin fragments. 2 Monoclonal globulinopathies have been reported in 2 Amazon parrots with malignant T-cell lymphoma; however, the a 1 and a 2 proteins were elevated. The nature of the proteins in those 2 parrots was not definitively determined.…”

Mechanisms of Humoral Hypercalcemia of Malignancy in Leukemia/Lymphoma

“…Cats may also develop HHM due to unknown humoral factors induced by feline leukemia virus infection (Engelman et al, 1985). Hypercalcemia has also been reported in an Amazon parrot with lymphoma (de Wit et al, 2003).…”