Cutaneous Mast Cell Tumor and Mastocytosis in a Black-masked Lovebird (Agapornis personata)

Abstract

A 12-year-old female black-masked lovebird (Agapornis personata) with a cobalt color mutation was presented for self-mutilation of a mass located on the right lateral neck. Cytologic evaluation of the soft tissue mass revealed a predominance of poorly stained mast cells with metachromatic intracytoplasmic granules. The presumptive diagnosis was cutaneous mast cell tumor. Clinical evaluation, results of a complete blood cell count and biochemical analysis, and radiographs did not reveal systemic manifestation of mast cell disease. The mass was surgically resected, but surgical margins were limited because of the location of the mass and the small size of the patient. The lovebird died the day after surgery. Gross postmortem examination revealed splenomegaly, multifocal pinpoint white nodules throughout the liver parenchyma, severe thickening and yellow coloration of the great vessels, and pale pink swelling of the caudal right kidney. Histopathologic analysis of the resected mass revealed sheets of round cells that contain metachromatic granules, defined as neoplastic mast cells, within a fine fibrovascular stroma. Similar neoplastic cells were seen in the right kidney, hepatic sinusoids, splenic pulp, periovarian connective tissue, and bone marrow. The histopathologic diagnosis was a cutaneous mast cell tumor and disseminated mast cell disease, or mastocytosis. To the authors' knowledge, this is the first reported case of a cutaneous mast cell tumor and mastocytosis in a psittacine bird.

Systemic mastocytosis with terminal leukemic manifestation in two dogs

“…In SM, biochemical analysis results may be unremarkable (3,16) or may reveal hypoalbuminemia (4,6), as seen in one of our patients. In this study, the decreased plasma proteins may have resulted from liver damage due to neoplastic infiltration and/or blood loss in the GI tract.…”

“…Unlike cats, dogs rarely develop visceral mastocytosis (4,7,9) and, when it occurs, it is commonly associated with a primary cutaneous MCT (3,18). In a previous study of canine SM, 14 of 16 dogs had a primary cutaneous MCT and only two had SM without a skin tumor (12), as found in Case 2.…”

“…In mammals, mast cells play a vital role in the immune system, by participating in hypersensitivity reactions, T-cell stimulation, and parasite defense (4). However, neoplastic proliferation of these cells is common in animals, especially dogs.…”

“…Similarly, we found that circulating neoplastic mast cell concentrations were variably lower (10.2% in Case 1 and 40.8% in Case 2). Apparently, anemia is a common finding in animals and humans with SM (4,6,12,16), possibly because of mechanisms involved in chronic diseases (16), myelophthisis (8), and/or blood loss through gastrointestinal (GI) ulceration (2). Leukocytosis in Case 1 was mainly attributed to mature neutrophilia, possibly associated with stress, GI tract ulcers, and/or tumor necrosis (12).…”

Diagnosis of Retrobulbar Round Cell Neoplasia in a Macaroni Penguin (Eudyptes chrysolophus) Through Use of Computed Tomography

“…Mast cell tumors have been reported in birds, but mast cells were ruled out as the round cell type in this case because the cells contained no granules and did not behave histologically like mast cells. 20 Although melanoma has been reported in birds, including a case in a macaroni penguin, the neoplastic round cells in this case did not contain melanin granules nor did they label with an IHC cocktail for melanoma cell-surface markers designed for canine melanomas, 21 which has anecdotally labeled melanomas in other penguins. 12 Immunohistochemistry has been used successfully in birds, including penguin species, to characterize lymphomatous neoplastic cells as either T-cell or B-cell in origin.…”