Melanoma is a sarcoma, not a carcinoma, and, in 1967, it still was known as the "black death," not because it always is "a highly malignant tumor," but because it so often went unrecognized clinically for decades, by which time it had metastasized. When it is macular and without signs of regression, melanoma is benign biologically. As long as neoplastic melanocytes of melanoma are confined to epidermis and to epithelial structures of adnexa, there is no possibility of metastasis from it having already occurred.

The contention of Lewis and Wheeler that melanoma develops as a consequence "of transition of a junction or other nevus" was accepted universally by physicians in 1967. In fact, the vast majority of melanomas in the world develop de novo and not in conjunction with a pre-existing nevus. It is true that melanoma, being the malignant neoplasm that it is, increases, albeit slowly, in size and often in depth of color, but those changes cannot be discerned by a clinician who sees a patient for the first time; such changes can be learned about from a history given accurately or by photographs of a lesion taken serially, not from assessment clinically on a single occasion. By the time that there is "crusting, bleeding, formation of nodules within the mole or its satellite lesions, and lymphadenopathy, the melanoma has already metastasized," and, for that reason, clinicians must be keenly aware that the first sign of melanoma, at a stage when it is curable easily by simple excision is "the appearance of a pigmented spot." Those melanomas that "resemble pyogenic granulomas" are exophytic and often ulcerated, by which time they nearly always have long since given rise to metastases.