The first to advise a system for staging primary cutaneous melanoma were L.V. Ackerman and Del Regato⁴ who, in 1947, devised a system of four tiers in which Stage 1 denoted the poorest prognosis and Stage 4 indicated the best chance for survival, long term, of a patient with melanoma. This is the scheme put forth by those collaborators:

Curiously, in subsequent proposals for constructing a system of staging, measuring sticks for prognosis were reversed consistently, to wit, Stage 1 came to indicate the best prognosis, Stage 2 a somewhat worse prognosis, and so on. Moreover, a chief consideration in the system of Ackerman and Del Regato, namely, status of lymph nodes clinically, was virtually abandoned during most of the ensuing half century.