Fluorescent Dopa Reaction of Nevi and Melanomas

In specimens treated according to the histochemical method of Falck and Hillarp, a specific fluorescence develops in melanocytes, nevus cells, and cells from malignant melanomas. There is support for the presumption that the fluorescence indicates the presence of dopa. The fluorescence of the epidermal melanocytes is faint. The fluorescence of dermal nevus cell aggregates is moderate in the parts adjacent to epithelium, whereas inner and deep parts fluoresced only faintly or not at all. The fluorescence of junctional nevus cells is more intense. Most of the cells in primary malignant melanomas and cutaneous metastases show a strong fluorescence, and single invading melanoma cells can easily be distinguished. The fluorescence intensity of melanoma cells of lymph node metastases varies within wide limits.