Mast Cell Tumors of the Gastrointestinal Tract in 39 Dogs

Abstract

Abstract. Mast cell tumors (MCTs) of gastrointestinal origin that had been surgically removed from 39 dogs were examined to evaluate their pathologic features. Miniature breeds, especially Maltese, were most frequently affected. The average age of affected dogs was 9.7 Ϯ 2.6 years. No sex difference was apparent. The most frequently affected sites were in the upper digestive tract, and the prognosis was very poor. Grossly, the gastrointestinal wall was prominently thickened, and the lumen of the affected gut was usually narrowed. Microscopically, there was diffuse transmural invasion of round to pleomorphic tumor cells. Tumor cells had moderate to abundant cytoplasm, round to ovoid nuclei with scattered chromatin, and mitotic figures. Fibrous stroma was observed in about half of the tumors. There was variable infiltration of eosinophils. In all tumors, cytoplasmic granules showed weak metachromasia, but the number of granules was very small. Immunohistochemical staining for c-kit and mast cell tryptase was positive in 77% and 62% of tumors, respectively. All tumors were positive for at least two of these markers. Immunohistochemical staining for p53 was positive in 13% of the tumors. Reactivity for staining markers and p53 was unrelated to cell pleomorphism, vessel invasion, or survival time. Gastrointestinal MCTs have histologic and immunohistochemical features completely different from those of other primary or metastatic gastrointestinal tumors. The combination of immunostaining for mast cell tryptase and c-kit and histochemical staining for metachromasia appears to be a powerful tool for the diagnosis of gastrointestinal MCTs.

Mast cells and canine mast cell tumours. A review

“…In France, relatively many young boxers were found to suffer from MCTs of low grade malignancy (9). Purebred male dogs of miniature breeds appear to have a relative high prevalence of intestinal MCTs (85,106). All breeds are susceptible however and both sexes are equally affected (9).…”

Cultivation and Characterization of Canine Skin-Derived Mast Cells

“…After blocking with 2.5% heat-inactivated horse serum, the preparations were incubated overnight with mouse antihuman tryptase monoclonal antibody (clone AAI; Serotec, Oxford, U.K.) or mouse IgG 1 isotype control (Rockland, Gilbertsville, PA, U.S.A.) diluted with 1.5% heat-inactivated horse serum in PBS at 4C. The anti-human tryptase monoclonal antibody has previously been shown to be cross-reactive with canine tryptase by immunohistochemistry [31]. The preparations were incubated with biotinylated panspecific universal secondary antibody and then a biotinstreptavidin peroxidase complex method was carried out according to the manufacturer's protocol.…”

Gastritis and Peptic Ulcer Diseases in Dogs: A Review

“…(Neiger, 2008), Gnathostoma spp. (McCarthy et al, 2000), Heterobilharzia americana (Rodriguez et al, 2014) and mastocytoma along with infiltration of eosinophils (Ozaki et al, 2002), lesions are rarely observed in Toxocara canis infestation (Chira et al, 2005). Focal type chronic hypertrophy occurs as a result of chronic administration of Aspirin.…”

“…Animals with mastocytosis may have numerous all over gastric ulcers (Stanton and Bright, 1989;Ozaki et al, 2002). The mast cell tumor produces and releases histamine, which binds to H2 receptors on gastric parietal cells, gives a powerful stimulant to acid secretion.…”