Fig. 2.

Histological features of common canine sarcomas. (A) Malignant peripheral nerve sheath tumor demonstrating characteristic concentric whirling of spindle cells around central sclerotic collagen (asterisk). (B) Osteoblastic osteosarcoma with polygonal neoplastic osteoblasts producing and embedded within eosinophilic neoplastic bone matrix (arrowhead). (C) Histiocytic sarcoma, characterized by marked cellular pleomorphism, with multi-nucleate and karyomegalic cells, and bizarre mitotic figures (arrows). (D) Splenic hemangiosarcoma. Neoplastic cells are forming irregular, anastomosing, blood-filled vascular spaces. 20x magnification, H&E staining.