Malignant fibrous histiocytoma of bone.

Existence of an entity called malignant fibrous histiocytoma of bone was emphasized, based on two of our own cases experienced recently and on previous reports related to this tumor. Histologically the tumor resembles markedly the malignant fibrous histiocytoma originating in the soft part. In addition, an attempt was made to clarify its biological behavior, histological subclassification and criteria to be malignant and differential diagnoses from several other bone diseases which sometimes mimic this malignant bone tumor.