Aspectos morfológicos e imunohistoquímicos de tumores de glândula adrenal em bovinos abatidos em frigoríficos em Mato Grosso

Abstract

Adrenal gland tumors in cattle, while relatively common, have been the subject of few comprehensive studies that describe their morphological characteristics and immunohistochemical profile. This study aims to fill this gap by providing a detailed description of the macroscopic, microscopic, and immunohistochemical aspects of adrenal gland neoplasms in cattle slaughtered in the state of Mato Grosso. The neoplasms were identified and characterized based on macroscopic, microscopic, and immunohistochemical findings. The macroscopic and microscopic findings revealed the presence of adrenal gland neoplasms, including cortical carcinomas (69%), cortical adenomas (21%), and pheochromocytomas (10%). Statistical analysis showed no significant differences in tumor size. Histologically, most cortical neoplasms presented a solid growth pattern characterized as well-defined masses organized in nests, cords, or trabeculae interspersed with delicate fibrovascular stroma. The cells were uniform, surrounded by oval-shaped cells with voluminous cytoplasm, slightly eosinophilic, often multivacuolated, and with indistinct borders. The distinction between adenoma and cortical adenocarcinoma, in the absence of metastases, was based on the detection of 3 or more of the following criteria: diffuse growth pattern, capsular invasion, vascular invasion, predominance of spindle cells, and nuclear pleomorphism. Most pheochromocytomas expand from the medullary region and compress the cortex, causing atrophy. They were characterized by solid masses arranged in nests delimited by delicate fibrovascular stroma. The cells were small, polyhedral, elongated, or spindle-shaped with granular cytoplasm. In all cases, immunohistochemistry was necessary to determine the diagnosis since there was great similarity with cortical adenomas. An immunohistochemical panel composed of antibodies against melan A, synaptophysin, and chromogranin A was considered useful for classifying cattle's most common adrenal tumors.