Experimental tumors with features of malignant histiocytomas. Morphological studies on neoplasms produced by inoculation of an established macrophage-like cell line (WEHI-3).
Soft tissue malignant histiocytomas are thought to be a histologic variant of malignant fibrous histiocytomas. By means of an established macrophage-like cell line (WEHI-3) we produced experimental tumors with light microscopic features of malignant histiocytomas. In spite of repeated subculturing of WEHI-3 cells and their derivatives the 6 tumor generations received by cell transplantations were remarkably constant in regard of their light and electron microscopic morphology. This was in contrast to preceding experiments with an established fibrosarcoma cell line. Electron microscopically they were never to be identified in the histiocytoma-like tumors so that these neoplasms could virtually not be considered as members of the malignant fibrous histiocytoma group. Our results support the idea that malignant fibrous histiocytomas and malignant histiocytomas of the soft tissues arise from undifferentiated mesenchymal cells and emphasize that monocyte-derived histiocytic tumors may appear as soft tissue histiocytomas although they are more related to malignant histiocytosis.
D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D018219:Histiocytoma, Benign Fibrous / Q000473:pathology* / Q000648:ultrastructure; D008264:Macrophages; D051379:Mice; D008808:Mice, Inbred CBA; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D051381:Rats; D011919:Rats, Inbred Strains