[DNA cytofluorometry of soft tissue tumors]

We carried out DNA cytofluorometry with propidium iodide stain on the 17 cases of soft tissue tumors including giant cell tumor of the tendon sheath, pigmented villonodular synovitis, 2 hemangiomas, 3 lipomas, 5 schwannomas, 3 neurofibromas, liposarcoma and synovial sarcoma. The benign tumors were characterized by regular polyploidization with very few S-phase cells, indicating slow tumor growth. Most of the malignant soft tissue tumors were associated with remarkable polyploidization with an increase in S-phase cells. However, some malignant tumors did not show polyploidization. We concluded, therefore, that an increase in S-phase cells is an important, cytofluorometric criterion for malignancy of soft tissue tumors.