Abstract

Background: Mast cells are one of the characteristic factors in angiogenesis, growth, and metastatic spread of tumors. Further studies are suggested to determine the type of these cells which might be useful in the assessment of biological nature of the tumor and its future treatment modality. Few studies have evaluated mast cell infiltration in visceral tumors, especially uterine tumors. Case presentation: In this study, age, sex, death rate, and histologic patterns were in agreement with those of previous reports on canine mast cell tumors. Cytopathology assays are widely used to prognosticate canine uterine mast cell tumors (MCT). There is limited information about these prognostic assays used on MCT that arise in the uterine. The anisocytosis and anisocytosis and giant cells were present in the tumor. Furthermore, the tumor had nuclear atypia with scattered multinucleated cells and prominent nucleoli and tumor were classified as poorly granulated. Under microscopic examination, we observed diffuse infiltration and proliferation of tumor cells from the uterine different area and the infiltrative characteristics and distribution patterns of neoplastic cells were observed. This tumor consisted of sheets and cords of uniform round cells with discrete cytoplasmic margins. Microscopically, the neoplastic masses were poorly-demarcated and lacked capsules and tumor cell usually showed a distinct cell boundary. Nevertheless, the neoplastic cells were located between collagen bundles forming small clusters and sheets and had large, centrally located, round to ovoid nuclei. In addition, eosinophils were scattered among the mast cells at the periphery of the masses. The presence of eosinophils and the observation, at high magnification, of cells with cytoplasmic metachromatic granules. Conclusion: Based on these findings, a diagnosis of poorly-differentiated mast cell tumor was made and data histologic grading was available for tumor. Neoplasm was poorly differentiated or gradeIII.