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The Desmoid Tumor Research Foundation

November 2023

Mammary fibromatosis in a female dog: case report

Author Information

Marina P Dos Reys 1, Lize A B Borges 1, Fernanda R Souza 1, Karen Y Nakagaki 2, Geovanni D Cassali 3

1Laboratório de Patologia Comparada, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, 31270-901, Minas Gerais, Brazil. 2Celulavet - Centro de Diagnóstico Veterinário, Avenida Santa Terezinha, 214, Santa Terezinha, Belo Horizonte, 31365-000, Minas Gerais, Brazil. 3Laboratório de Patologia Comparada, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, 31270-901, Minas Gerais, Brazil. Electronic address: cassalig@icb.ufmg.br.

Publication

J Comp Pathol

Summary

Fibromatosis, or desmoid tumour, is characterized by excessive and infiltrative proliferation of connective tissue originating from aponeurotic muscle structures. Mammary fibromatosis is rare in humans and animals and its precise aetiology is unknown. A 10-year-old mixed-breed female dog developed a mass in the right cranial thoracic mammary gland (M1) and underwent lumpectomy. The mass was firm, with an irregular surface and distinct limits. Microscopically, it was a neoplastic proliferation of fusiform cells with low atypia, interspersed with abundant dense collagenous tissue, confirmed by histochemical staining with Gomori's trichrome and Masson's trichrome and immunopositivity for vimentin and smooth muscle actin, confirming mammary fibromatosis. Mammary fibromatosis in dogs needs further studies to elucidate its clinical, epidemiological and aetiopathogenic aspects.

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