RESUMO
Mast cell tumors are among the most common canine cutaneous neoplasms. These tumors are routinely graded with regard to malignancy based on histomorphological features which are related to the post-surgical course of the disease. This classification is the main criterion for clinicians and surgeons to direct the therapy. However, mast cell tumors biologic behavior is extremely variable, leading to frequent failure in treatment. This occurs, for the most part, in tumors with moderate differentiation and can be explained by the fact that they share histomorphological features with the well-differentiated and the poorly-differentiated tumors. Because of these difficulties, several methods have been studied with the objective of predicting tumor behavior and the evolution of the cases in a more precise and trustful manner. The present work reviews the main aspects of this important neoplasm, as well as the available literature about the prognostic indicators, commenting their advantages, disadvantages and the results obtained by various authors.
Assuntos
Animais , Cães , Prognóstico , Mastocitoma/fisiopatologia , Mastocitoma/veterináriaRESUMO
Immunohistochemical staining is useful in the diagnosis of bone marrow infiltration in systemic mastocytosis. However, it is not clear if antibody staining may be helpful in the diagnosis of cutaneous mastocytosis (CM). We studied the histological appearance of CM in 35 pediatric patients. Cases were assigned to three basic clinical groups: I--Urticaria pigmentosa (UP, n=29); II--Mastocytomas (n=4); and III--Diffuse Cutaneous Mastocytosis (DCM, n=2). The analysis of clinical information revealed an association between the presence of diarrhea and a higher number of cells/field. Nine doubtful cases, all of them macules, were selected based on the scarcity of mast cells (MC) and the absence or rarity of other inflammatory cells. We compared the number of cells identified in Giemsa and immunohistochemical stains in definite and doubtful cases. The intraclass correlation statistic tested the concordance between each staining method. All 9 dubious cases according to the Giemsa stain had their CM diagnosis confirmed by the immunohistochemistry analysis. The intraclass correlation between Giemsa and c-kit was good (0.7) when the number of MC was high. However, there was no correlation between the mast cells counts in the two different stains in the dubious cases. The immunohistochemistry with c-kit might make CM diagnosis easier, especially in the macular cases, when there is a lower number of MC.