Primary cutaneous osteoblastic osteosarcoma: a case report and review of the current literature.

Osteosarcoma is a malignant bone-forming tumour that typically arises within the metaphysis of long bones. Extraskeletal osteosarcoma is a rare variant that usually arises in the deep soft tissues, especially in the legs. We report a 65-year-old white man with an ulcerated, nodular lesion of the forearm. Based on the histological features and immunohistochemical profile of the tumour, a diagnosis of osteoblastic osteosarcoma was made. Osteosarcoma arising in the skin is a rare condition that has seldom been reported in the English literature.