From de microscopic analysis of 1,371 cases of alterations in the mammary gland, according to the morphological characteristics of benign and malignant tumors, from the records in the Animal Pathology Sector at the Pathology Department in Faculdade de Medicina Veterinária e Zootecnia / USP, from 1936 to 1999, the following number of cases was found: 1,249 cases malignant neoplams, 111 benign neoplasms and 11 cases of mammary duct hyperplasia. In the analysis of the malignant neoplasms, according to their histogenesis, 1,227 carcinoma cases and 22 sarcoma cases were found.
For the reclassification of each case, according to WHO, 578 specimens were used, for many slides were deteriorated and / or the material in the blocks was not representative.
The results of the study are presented in tab. 1, 2, 3 and 4 and fig..