Desmoplastic reactions associated with malignant canine mammary tumours

Desmoplastic reactions or desmoplasia, characterised by proliferation of fibrotic connective tissue around tumour cells, have been described as a prognostic indicator of malignancy in human breast cancers. Desmoplasia ultimately results in deposition of collagen that shows significant differences in its density and orientation at different stages of tumourigenesis. The different collagen patterns associated with tumours are referred to as tumour associated collagen signatures (TACS) and are identified as hallmarks in human tumourigenesis. The present study was aimed to demonstrate the presence of TACS in canine mammary tumours (CMTs). The desmoplastic reactions and collagen deposition occurring in association with CMTs were analysed using routine histopathological, special staining and scanning electron microscopy techniques. Thirty excisional biopsy samples collected from malignant CMTs were utilised for studying the progression of desmoplastic reactions occurring in the tumour associated stroma.