[Histogenesis of malignant fibrous histiocytoma and giant-cell tumor of bone].

Ten tumours: 5 malignant fibrous histiocytomas (2 with a primary site in the bone and 3 in the soft tissue), 3 giant cell bone tumours (one of them was malignant with metastasis to the lung) and 2 osteogenic sarcomas were studied in organ culture. The blood was added into some tumour pieces with a subsequent examination of blood phagocytosis by means of checking the hemosiderin granule accumulation in the cell cytoplasm. Malignant fibrous histiocytoma and giant cell bone tumour were very similar by the pattern of their growth and phagocytic activity of their cells; both differed strikingly from the osteogenic sarcoma. This implies the histogenetic similarity of malignant fibrous histiocytoma and giant cell tumour of the bone.