Consensus regarding the diagnosis, prognosis and treatment of canine mammary tumors: benign mixed tumors, carcinomas in mixed tumors and carcinosarcomas

Abstract

Mammary neoplasms are the most frequent tumors in female dogs. Of these neoplasms, benign mixed tumors (BMTs) and carcinomas in mixed tumors (CMTs) represent a large proportion of small animal oncology diagnoses. Together with carcinosarcomas (CSs), these three neoplastic entities are characterized by the proliferation of benign or malignant epithelial, myoepithelial, and mesenchymal cells, depending on their histological types. This histological heterogeneity, in addition to their molecular heterogeneity, confers these tumors with distinct biological behavior, which results in the need for different clinical and therapeutic approaches. The present consensual document elucidates the oncological issues related to the diagnosis, prognosis, and treatment of BMTs, CMTs, and CSs of the canine mammary gland.

Epidemiological, clinical and pathological evaluation of overall survival in canines with mammary neoplasms

“…Karayannopoulou et al (2005) observed that female dogs with undifferentiated carcinomas (grade III) presented a worse prognosis than female dogs with grade I and II carcinomas. Ulceration, necrosis and recurrence were proposed as prognostic factors (Cassali et al, 2014), which corroborated the findings of this study because these characteristics showed a higher frequency in the malignant mammary neoplasms. Ulceration can be caused by invasive tumor growth, ischemia or skin infection, although these characteristics are not necessarily associated with aggressive biological behavior.…”

“…Several classification methods for canine mammary tumors have been proposed (Misdorp et al, 1999;Goldschmidt et al 2011;Cassali et al 2014), which makes comparisons of studies on the biological characteristics of malignant neoplasms difficult (Sarli et al, 2002). The classification criteria adopted in the present study allowed an adequate histopathological diagnosis that was associated with the clinical evolution of the patient.…”

“…The high rate of malignancy observed is also associated with a higher frequency of mixed neoplasms. Mixed tumors are the most frequent neoplasms of mammary glands in female dogs (Cassali et al, 2012). These tumors may undergo malignant transformation and give rise to carcinoma in mixed tumor, carcinosarcomas and sarcomas in a mixed tumor (Misdorp et al, 1999;Cassali et al, 2012;Cassali et al, 2014;Cassali et al, 2017).…”

“…All tumors were fixed in 10% buffered formalin, paraffin embedded and routinely prepared and stained with hematoxylin and eosin (HE). Tumors were classified according to Consensus for the diagnosis, prognosis and treatment of canine mammary tumors (Cassali et al, 2014, Cassali et al, 2017. When the dog had multiple masses, the worst prognostic tumor was chosen for the analysis.…”

Immunodetection of myeloid and plasmacytoid dendritic cells in mammary carcinomas of female dogs

“…Only samples of simple type mammary carcinomas (tumor group) were selected as described by Cassali et al (2011) and classified as tubular, papillary and solid carcinoma. The grade of malignancy of the tumors was based on Elston and Ellis (1998).…”