Melanosis Circumscripta Praecancerosa (Dubreuilh) A Non-Nevoid Premelanoma Distinct from Junction Nevus**From the Departments of Dermatology, Wayne State University College of Medicine and Detroit Receiving Hospital (Hermann Pinkus, M.D., Chairman) and the Detroit Institute of Cancer Research (William L. Simpson, M.D., Scientific Director), Detroit, Michigan.Supported in part by research grant RG-4435 and C-2072 from the National Institutes of Health, U.S. Public Health Service, and in part by research contract DA-49-007-MD-584 from the Research and Development Division, Office of the Surgeon General, Department of the Army.Abridgement of a portion of a thesis submitted by Dr. Mishima to the Faculty of the Postgraduate School of Medicine, University of Tokyo, in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Dermatology and Syphilology.