Canine mammary osteosarcomas

Abstract

This article describes five representative cases of canine mammary osteosarcomas and induced tumours by a cloned canine mammary osteosarcoma cell line in nude mice. All five primary tumours were combined mammary osteosarcomas i.e. composed of both cartilage and bone tissues. In four of the five cases the metastases were also combined osteosarcomas. However, for the metastases in one dog and in the nude mice, only bone forming and spindle cell tumours were seen. The metastases were spread directly to the lungs by the blood in three dogs, and via the lymph nodes in two dogs. The metastases differed in morphology, both within and between different metastatic sites. Some of the metastases had an even lower grade than the corresponding primary tumour. © 2014 Hellmen E.