Dedifferentiated chondrosarcoma of bone with prominent rhabdoid component

Abstract Dedifferentiated chondrosarcomas (DDCS) are rare lesions, defined as tumors having a low-grade chondrosarcomatous component with an abrupt transition to a high-grade sarcoma. Although “malignant fibrous histiocytoma” (undifferentiated pleomorphic sarcoma) is the most common high grade saromatous component, many different types of sarcoma have been described. We present a case of dedifferentiated chondrosarcoma with rhabdomyosarcomatous differentiation harboring a prominent rhabdoid tumor component. To our knowledge, rhabdoid morphology in dedifferentiated chondrosarcoma has not been described in the English-language literature. The pathologic and radiologic features of this case are presented.