Concordance between clinical presentation and histopathological staging canine mammary tumors

In this work it was examined the concordance between clinical staging and histopathological staging of mammary tumors in 32 female dogs. It was observed that the average age of presentation of the pathology was 9 years (ranged from 6 to 12 years). The most affected mammary glands were the caudal abdominal and the inguinal, 20 out of 32 female dogs had multiple tumors (62%), and 38% single tumors. Regarding the breeds, the most frequent ones were mixed breeds, Poodle, Cimarron (native breed of Uruguay) and Labrador Retriever. Of the 32 female dogs with breast tumors studied, 65% had histopathological diagnosis of malignant tumor, while 35% had benign tumors. Clinical staging data showed that 64% of the cases with benign tumors were in stage I (1 to 3 cm) and 36% were in stage II (3 to 5 cm). Among those diagnosed with malignant tumors, 10% were in stage V, 57% in stage III, 9% in stage II, and 24% in stage I. There were no animals in stage IV. The most frequently found malignant tumors were tubular carcinoma and complex carcinoma, followed by solid and tubulopapillary carcinomas. Within the benign tumors, complex adenoma was the most frequent, followed by benign mixed tumor and simple ductal papilloma. The concordance between clinical staging and histopathology was low, as we could observe both benign T2 (3 to 5 cm) and malignant T1 (1 to 3 cm) tumors.