Fine needle aspiration cytology of malignant melanoma of the skin.

Fifty malignant melanomas of the skin were aspirated with a fine needle, and the cytomorphologic features of the smears were evaluated. An attempt was made to establish the frequency of morphologic features found in melanoma cells. The following features were regarded as frequent: lack of cohesiveness between the malignant cells; binucleated, multinucleated and giant cells; and intranuclear "vacuoles." The nuclei usually had a regular outline, and the nuclear chromatin was evenly distributed. The majority of the smears contained a mixture of epithelial-type and spindle cells. The nuclei of the epithelial-type cells were usually in an eccentric position. The morphologic features of malignant cells in smears, as described, can be helpful in making the preoperative cytologic diagnosis of nonpigmented malignant melanoma of the skin.