CANINE EXTRASKELETAL OSTEOSARCOMA OF THE SALIVARY GLAND

Abstract

An 8 year-old male mongrel dog and 12 year-old male German Shepherd had a 10 x 10 cm mass and 15 x 10 cm mass located in the mandibular region. The encapsulated firm white masses had multiple cysticlike nodules filled with mucous. Histopathology revealed clusters of pleomorphic, large, round to oval shaped cells, irregular ovoid to spindle nuclei with highly mitotic figures that showed osteoid and bony formation. The neoplastic cells were immunoreactive in some parts for vimentin and cytokeratin but not for desmin, α-SMA and S-100 protein. Hyperplastic salivary gland cells were also present. Electron microscopy revealed prominent nucleoli with an abundant, dilated, rough, endoplasmic reticulum. A final diagnosis of extraskeletal osteosarcoma originating from interstitial cells of the salivary gland was made.