Neoplasias melanocíticas em bovinos abatidos em frigorífico

Abstract

The tumors of melanogenic system are poorly understood. There are large differences between species of domestic animal in the occurrence of pigmented neoplasms. These tumors are common in old gray horses and in dogs, uncommon in pigs, and are rare in cats and sheep. They are not identical morphologically in different species and their histogenesis is almost entirely unknown. Comparable conditions exist only in dogs and pigs. For theses reasons it seems impossible at present to give a classification valid for all domestic animals. This work aims to study the prevalence and morphologic aspects of melanocitic neoplasms of slaughtered bovines from a abbatoir of the north region of Mato Grosso State. From a total of 175.544 slaughtered cattle, 275 presented gross lesions with appearance of neoplasms. After histologic evaluation, 141 assays was confirmed like neoplasms and from that 38 was characterized in melanocytic neoplasms (16 melanomas and 22 melanocytomas). The morphologic aspects from each tumor was discussed.