Ackerman

 
"At the very outset, malignant melanoma is entirely invisible clinically and it probably takes a long time before the neoplasm can be suspected of being what it truly is with the naked eye. By that time the lesion must measure at least 3 mm in greatest diameter. Before it reaches that size, a tannish macule of malignant melanoma would be difficult to differentiate clinically from a freckle or an evolving solar lentigo. Even when still small (i.e. less than 6 mm), however, flat lesions of malignant melanoma have clinical features that usually enable differentiation of them from simple lentigines and junctional nevi. As a rule, small malignant melanomas are asymmetrical, poorly circumscribed with notched, scalloped, or jagged borders, and mottled in pigmentation by nuances of brown that sometimes are tinged with black, blue, and even pink . . . In short, small, flat lesions of malignant melanoma are clinically diagnosable."
 
Ackerman AB. Malignant melanoma in situ: The flat, curable stage of malignant melanoma. Pathol 1985;17:298.
 

Brief critique

 
As was his emphasis from the early 1980s, Ackerman's stress here is on small (even 3 mm in greatest diameter) flat lesions of melanoma. The features mentioned enable diagnosis clinically of many, but not all, "small, flat lesions of malignant melanoma." That statement is true, too, of diagnosis accurately by conventional microscopy of small lesions of melanoma. Criteria available even today simply are not sufficiently refined to permit diagnosis with surety of every small, flat lesion of melanoma, clinically or histopathologically.