Connective Tissue-Type Mast Cell Leukemia in a Dog.

Abstract

ABSTRACT. An unusual case diagnosed as connective tissue-type mast cell leukemia with marked mastocyte infiltration into visceral organs in a seven-year-old female Curly-Coated retriever is presented. Acute circulatory collapse, emesis, diarrhea, abdominal enlargement, icterus, cyanosis, dyspnea, pulmonary edema, hepatomegary, ascites, and right ventricular enlargement were observed. Hematologic and biochemical examinations revealed mast cell leukemia, mature neutrophilia, monocytosis, thrombocytopenia, hemolytic hyperbilirubinemia, hyperhistaminemia, renal and hepatic injuries. Mast cells were distributed systemically, but predominantly in the diaphragm and liver with a large mass among the serosa of ileum, cecum and colon. Mast cells were stained intensely by both safranin and berberine sulfate.-KEY WORDS: canine mast cell leukemia, connective tissue type, visceral mast cell tumor.J. Vet. Med. Sci. 62(2): 187-190, 2000 gravity and pH were 1.035 and 6.0 respectively. Serum biochemical findings revealed marked renal injury and hemolytic hyperbilirubinemia (Table 1). Serum protein electrophoresis was within normal limits. Later, plasma histamine concentrations of this case were found to be approximately 1,000-folds higher than those of two normaladult beagle dogs (0.45 and 0.49 ng/ml). Venous blood gas and serum electrolyte analyses showed profound metabolic alkalosis, hypokalemia and hypochrolidemia (Table 1). At this time, the dog was diagnosed as having mast cell leukemia, and treated with dexamethasone, cimetidine, aminophylline, ampicillin and fluid. However, the dog died on day 2 and was then necropsied.Gross examination revealed a large mass measuring 16.5 × 13.0 × 5.0 cm among the serosa of the ileum, cecum and colon. The mass was coarsely rough on the surface, encapsulated and irregularly lobulated with grayish white necrotic and hemorrhagic areas on the cut surface (Fig. 2). The liver was swollen with irregular whitish discoloration, and ascites was very evident. The cardiac right ventricle was dilated, and the lung was diffusely congested; the tracheobronchial lymph nodes were enlarged. Gastroduodenal ulcer, congestion and hemorrhage were also observed.Histologically, neoplastic mast cells were determined in the mass. They were also distributed predominantly in the diaphragm and liver, mildly in the spleen and bone marrow, minimally in the heart, lung, kidney, adrenal gland, urinary bladder and uterus. The tumor cells had cytoplasm containing small to large granules that were stained metachromatically with toluidine blue. These tumor cells were identical to those found in the peripheral blood. Furthermore, tissue sections were stained with alcian bluesafranin, and with berberine sulfate, which is a fluorescent dye that specifically stains heparin, according to the method Visceral mast cell tumor (MCT) and mast cell leukemia are rare in dogs in contrast to cats [10,12]. Several reports are available on mast cell leukemia associated with systemic MCT in dogs [1,2,6,8,13,15,17]. However, reports on cli...

Systemic mastocytosis and probable mast cell leukaemia in a koala (Phascolarctos cinereus)

“…26 Circulating atypical myeloid cells were not identified in two case reports of canine mast cell leukaemia. 27,28 In the current koala case, there was a dominant population of mast cells in the marrow commonly with immature/atypical morphology, a dominant population of mast cells in the peripheral blood and a population of circulating atypical mononuclear cells, appearing similar to MCL-AML in humans. 22…”

Systemic mastocytosis with terminal leukemic manifestation in two dogs

“…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.…”

“…Mast cell tumors (MCTs) are the most common skin tumor in dogs, comprising up to 21% of all canine cutaneous neoplasms (2). Conversely, systemic or visceral mast cell neoplasia is rare in dogs (3,7,9) and is generally characterized by a primary cutaneous mass of poorly differentiated cells (3).…”

“…Moreover, standardized diagnostic criteria for canine MCL are lacking. One study (9) reported a patient with an abdominal mass associated with mastocythemia (42% mast cells), highly increased plasma histamine concentration, and bone marrow cytology with 300-400 mast cells/1,000 nucleated cells. Another study (7) reported a dog with marked mastocythemia (43% mast cells), associated with moderate anisocytosis, karyolysis, and degranulation.…”

Pleural Fluid from a Dog with Marked Eosinophilia

“…According to one study, purebred male dogs of miniature breeds (Maltese, Chihuahuas, Pomeranians, and Yorkshire Terriers) have a higher incidence of visceral mast cell tumors. The median age reported for dogs affected with visceral mast cell neoplasia is 8 years with a range of 6–12 years 2–4 . The etiology of mast cell tumors, both cutaneous and visceral, is unknown; however, hereditary and viral causes have been proposed, and rarely tumor formation has been associated with the application of skin irritants or chronic inflammation 1,2 …”