Grimelius' silver method for all types of malignant melanomas.

Various cytologic appearances of malignant melanomas represent a great diagnostic problem in the pathologist's everyday work. The new Pearse concept that the melanoblast/cyte is the APUD cell led the authors to the idea of using Grimelius' silver method, characteristic of APUD cells, in the diagnostic pathologic work of both melanotic and amelanotic malignant melanomas. The results are based on the examination of 20 tumours. All types of malignant melanomas were Grimelius reactive. The blanching by hydrogen peroxidase of Grimelius reactive cells makes this silver reaction specific in the study of melanomas.