A comparative study between mixed-type tumours from human salivary and canine mammary glands

Marisa Cls Genelhu,Geovanni D Cassali,Sérgio V Cardoso,Helenice Gobbi

doi:10.1186/1471-2407-7-218

Marisa Cls Genelhu, Geovanni D Cassali + Show 2 more

Open Access

https://doi.org/10.1186/1471-2407-7-218

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Abstract

BackgroundIn comparative pathology, canine mammary tumours have special interest because of their similarities with human breast cancer. Mixed tumours are uncommon lesions in the human breast, but they are found most frequently in the mammary gland of the female dogs and in the human salivary glands. The aim of the study was to compare clinical, morphological and immunohistochemical features of human salivary and canine mammary gland mixed tumours, in order to evaluate the latter as an experimental model for salivary gland tumours.MethodsTen examples of each mixed tumour type (human pleomorphic adenoma and carcinomas ex-pleomorphic adenomas and canine mixed tumour and metaplastic carcinoma) were evaluated. First, clinical and morphologic aspects of benign and malignant variants were compared between the species. Then, streptavidin-biotin-peroxidase immunohistochemistry was performed to detect the expression of cytokeratins, vimentin, p63 protein, estrogen receptor, β-catenin, and E-cadherin.ResultsAfter standardization, similar age and site distributions were observed in human and canine tumours. Histological similarities were identified in the comparison of the benign lesions as well. Metaplastic carcinomas also resembled general aspects of carcinomas ex-pleomorphic adenomas in morphological evaluation. Additionally, immunohistochemical staining further presented similar antigenic expression between lesions.ConclusionThere are many similar features between human salivary and canine mammary gland mixed tumours. This observation is of great relevance for those interested in the study and management of salivary gland tumours, since canine lesions may constitute useful comparative models for their investigations.

Highlights

In comparative pathology, canine mammary tumours have special interest because of their similarities with human breast cancer
Spontaneous tumours of canine mammary glands have been proposed as comparative models for the study of human breast cancer, since these lesions share epidemiological, clinical, behavioural and antigenic features [2,3,4,5]
We have demonstrated that commercially available antibodies for the study of human neoplasias are functional to detect antigenic expression in canine lesions

Summary

Introduction

Canine mammary tumours have special interest because of their similarities with human breast cancer. The aim of the study was to compare clinical, morphological and immunohistochemical features of human salivary and canine mammary gland mixed tumours, in order to evaluate the latter as an experimental model for salivary gland tumours. Because of centuries of coexistence with humans in the same environment, dogs are of particular interest as they provide important evolutionary information. Both species show great genotypic similarities [1]. Spontaneous tumours of canine mammary glands have been proposed as comparative models for the study of human breast cancer, since these lesions share epidemiological, clinical, behavioural and antigenic features [2,3,4,5]. Ductal carcinomas [13,14], adenoid cystic carcinomas and mixed tumours with similar patterns may be found in both organs [15,16]

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