Cytological studies of human malignant melanoma cultured in vitro.

tured human melanocytes in vitro and included two malignant melanomas in his report of a large series of tissue cultures. Subsequent studies on the growth of normal and neoplastic human melano cytes were carried out by Takano (18), Timofeyev ski (19), Sano and Smith (17), Grand and Cam eron (8), Fjelde (6), and Funan Hu (7). All these authors concluded that growth in tissue culture was characterized by the appearance of macro phages and fibroblasts as well as melanocytes. It was observed that the melanocytes became pre dominant in the later stages of culture. Although electron microscopy studies of human malignant melanoma tissues have been carried out by Wellings and Siegel (21—23) and by Braun steiner ci at. (3), the electron cytology of melano ma cells grown in culture has not, as yet, been de scribed. In the investigation under discussion a cytological study of human malignant melanoma cells growing in tissue culture, utilizing cytochemi cal and electron microscopic technics, was under taken.