Preoperative diagnosis of malignant melanoma using the touch-fluorescence method.

We have developed a touch-fluorescence method using preparations from the outer surface of elevated and ulcerative malignant melanoma lesions. This method allows the demonstration of the melanogenic activity of melanoma cells within 30 min and has made it possible to definitively diagnose a lesion as malignant melanoma at the initial examination. In 21 cases clinically diagnosed as typical melanoma, 17 were definitively diagnosed as melanoma from the touch-fluorescence microscopic findings. Of the four cases in which no fluorescent tumor cells were found, two proved not to be melanoma. There was some correlation between the morbid types of primary melanoma and the configuration of fluorescent melanoma cells, the main cellular configuration of superficial spreading melanoma being round whereas that of nodular melanoma and acral lentigenous melanoma was pleomorphic. Based on the above results, this method was concluded to be extremely reliable for the preoperative diagnosis of elevated and ulcerative lesions of malignant melanomas, which are sometimes difficult to diagnose.