Immunohistochemical Study of Giant Cell Osteosarcoma in a Dog

Case Description and Clinical Findings- A seven-year-old male German shepherd dog was referred to Small Animal Clinic with severe lameness (non-weight-bearing) and considerable localized proximal right humerus swelling. Radiographic study revealed severe soft tissue swelling and pathologic fracture of proximal right humerus. Immediately, the right forelimb was removed surgically and once sample was sent to pathologic laboratory for staining and immunohistochemical studies. Seven antibodies were used for immunohistochemical study of sample removed. Treatment and Outcome- Dog tolerated operation and recovered in 12 hours after surgery with no post-operative complication. The sample removed was giant cell osteosarcoma in H and E staining study. This tumor was with low mitotic and metastatic activity in immunohistochemical study. Clinical Relevance- Immunohistochemical study showed that antibodies used for histologic study could determine origin of tumor and being metastatic character of tumor for predicting of survival time and how to manage (medical and surgical treatment) this type of bone neoplasia.