RESUMEN
Bovine adrenal gland tumours are considered relatively common, although scarce data are available about their real incidence, pathological characterization, classification criteria and immunohistochemical profile. This study describes the morphological and immunophenotypical characteristics of 35 dairy cattle adrenal gland tumors from Northern Italy and compare them with human pathology. Macroscopical, histological, histochemical and immunohistochemical investigations were performed. Microscopically proliferative lesions were classified as focal hyperplasia (8/35), primary cortical tumors (15/35) , primary medullary tumors (12/35). The cortical tumors showed a highly heterogeneous spectrum of morphological aspects not matching the two major diagnostic categories of adenoma and carcinoma in either cattle or humans. The medullary tumors (7 neuroblastomas and 5 pheochromocytomas) showed morphological and immunophenotypical features largely overlapping with human counterparts. Although limited by the small number of neoplasms and the lack of evidence of metastases precluding a clear distinction between benign and malignant lesions, this study represents the first attempt to compare the bovine and the human pathology. The present data support the concept that adrenal tumors in cattle have distinctive features that deserve a species- specific classification.