Radioactive Phosphorus in the Diagnosis of Skin Tumors

Cells with increased metabolic activity require more phosphorus than similar cells with normal metabolism. This fact has been utilized to localize malignant lesions, both primary and metastatic, by external counting of concentrations of radioactive phosphorus (P3-) as a tracer. This study was undertaken in an attempt to develop a simple clinical procedure whereby benign nevi could be differentiated from malignant melanomas even before biopsy, since the extent of the biopsy could be influenced by such knowledge. Evidence of increased radiophos- phorus concentrations may also be of help in equivocal histopathological interpretations, which are so common in so-called juvenile melanomas and junction nevi. This preliminary report gives data on 70 patients with a wide variety of benign and malignant skin tumors, with emphasis on intradermal nevi and malignant melanomas. METHOD Radioactive phosphorus (P32 sterile solution) is injected intravenously in doses of from 100 to 150 p.c. This dose is far below