Establishment of a human dermatofibrosarcoma protuberans cell line: cytological characteristics.

We established a dermatofibrosarcoma protuberans (DFSP) cell line derived from a DFSP tumor from a 69-year-old female. The population doubling time of the cells was about 45 hours. The cells were mostly round, although a few triangular or spindle-shaped cells were also found. They could not be transplanted into nude mice. These cells had some histiocyte characteristics which are not observed in fibroblasts: 1) Electron microscopically, there were more lysosomes and phagolysosomes than in fibroblasts. Dense bodies and myelin figures derived from lysosomes were also observed. 2) Staining with acid phosphatase (ACPase), esterase, and alpha-1-antitrypsin was positive. 3) The cells had C3 receptors but no Fc receptors. However, there were two differences between DFSP cells in the established line and those in the early stages: in the former, the capacity for immunophagocytosis (Fc receptors and phagocytosis of Candida albicans) and collagen synthesis were almost entirely absent.