Secondary tumoural valvulopathy in a dog.

This short report describes a case of tricuspid valvular metastasis of canine disseminated histiocytic sarcoma in a 9-year-old female Rottweiler. Immunohistochemically the malignant neoplastic cells gave a strong reaction for vimentin and lysozyme, and showed negativity for serotonin, CD3, CD79a and cytokeratin. The intratumoural microvessels were detected by immunohistochemistry using CD31 and claudin-5. This appears to be the first report of a valvular metastasis of canine malignant histiocytosis.