[Value of ultrastructural morphology in the preparation of oncolysates of human malignant melanoma].

The culture of human cutaneous malignant melanomas is an important stage in the preparation of oncolysates for therapeutic purposes. The authors recall the definition of oncolysate: lysis of the malignant melanocyte by vaccinia virus liberates masked antigens which when reinjected into the patient accelerate or restimulate the production of antibodies. Culture is used to increase the number of malignant melanocytes, i. e. antigenic material, which is an essential precaution in tumours of small size. Production of oncolysate requires the exclusive use of the malignant melanocyte, i. e. the importance of morphological identification during the "in vitro" phase. The optical criteria defined by Fedoroff are inadequate and a source of error. Ultrastructural studies render this identification more valid, insofar as the normal and pathological markers which are the melanosomes are better known. Ultrastructural studies may be used to differentiate the malignant melanocyte from the ordinary macrophage in media which are black, and light cultures to distinguish fibroblastic growth, with no antigenic value, from the malignant melanocyte without pigment (achromic), recognisable by its premelanosome.