From Melanocytes to Melanoma Cells: Characterization of the Malignant Transformation by Four Distinctly Different Melanin Fluorescence Spectra (Review).

The melanin fluorescence emitted by pigment cells of the human skin has been a central research topic for decades, because melanin, on the one hand, protects against (solar) radiation in the near-UV range, whereas on the other hand, melanocytes are the starting point for the malignant transformation into melanoma. Until recently, however, melanin fluorescence was not accessible in the context of conventional spectroscopy, because it is ultraweak and is overshadowed by the more intense so-called autofluorescence of endogenous fluorophores. The advent of a new method of laser spectroscopy has made this melanin fluorescence measurable in vivo.

Early diagnosis of melanotic melanoma based on laser-induced melanin fluorescence.

Because of the increasing incidence of skin cancer, interest in using the autofluorescence of skin tissue as a noninvasive tool for early diagnosis is enforced. Focus is especially on malignant melanotic melanoma. On the basis of a newly developed method to selectively excite melanin fluorescence of skin tissue by stepwise two-photon excitation with nanosecond laser pulses at 810 nm, we have investigated information from this melanin fluorescence with respect to the differentiation of pigmented lesions.