Multiple primary melanoma. Case report and study of tumor growth in vitro

An unusual case of widespread multiple primary melanomas is described. Light microscopic study of all the excised lesions showed typical primary skin melanomas. In vitro, the cells grew more rapidly and showed greater loss of contact inhibition when the patient's own serum was substituted for fetal calfserum or pooled human serum in the culture media. An activating factor in the homologous serum or the production of a more favorable growth environment by this serum are possible explanations for the enhanced growth in human serum.