Immunohistochemical diagnosis of metastatic myxoid chondrosarcoma in dogs

Abstract

An 11 year old female Doberman was presented with the mass on the left forelimb. The animal was having clinical signs of lethargy, weight loss and decreased appetite for the past two weeks. Physical examination revealed hard painful swelling on the left humerus head region and the skin over the mass was normal. Radiographic examination of the head region of left humerus revealed irregular calcified areas and osteolytic changes. On necropsy, spherical, greyish-white, hard, varying sized (0.5-3.5cm) multiple nodules were noticed on the lungs, bronchial lymphnodes, heart, liver, spleen and kidney. Cytological examination demonstrated that round neoplastic chondroblasts with high variable nuclear to cytoplasmic ratios. Anisocytosis and anisokaryosis were marked. Histopathologicaliy, tumor mass present in humerus revealed pleomorphic cartilage lobules were separated by anaplastic spindle cells and vascularized fibro-connective stroma. Neoplastic cells revealed approximately 90% of positive cytoplasmic immunoreactivity with antibodies against vimentin and negative for cytokeratin.