Moynihan

 
"In recent years, greater understanding of the appearance and behavior of melanoma coupled with aids such as epiluminescence microscopy have led to more frequent diagnosis at an early curable stage. The ABCDs of melanoma have been a useful educational tool for the public to increase its awareness of this form of skin cancer. However, as our diagnostic skills improve, the limitations of this mnemonic have become more apparent.
 
Obvious asymmetry is not an early sign of melanoma. It is usually present in lesions that have reached a significant diameter. Use of the term border is somewhat redundant in that most tumors with an irregular border will have some degree of asymmetry and vice versa. This distinction may be confusing for many persons. Irregular color is always significant and perhaps should come first in any educational guide. Melanomas are being diagnosed at diameters less than 6 mm . . ."
 
"I would like to propose a mnemonic that is simple, concise, and easier to remember: the 3 Cs of melanoma.
 
The first C is color, which is most important. Most melanomas are irregular in color with shades of black and brown and sometimes red, white, or blue.
 
The second C is contour, which means shape and refers not only to irregular outline or border but may also include an irregular surface, as seen in more advanced tumors.
 
The third C stands for change. Regardless of size, color, or contour, a rapidly growing cutaneous lesion, especially when out of proportion to other lesions should be evaluated by a physician. Change in size, in addition to color and shape, are well accepted as major signs of the Glasgow 7-point checklist for melanoma screening . . ."
 
Moynihan GD. The 3 Cs of melanoma: Time for a change? J Am Acad Dermatol 1994;30:510–1.
 

Brief critique

 
Moynihan is right about some of the limitations of the ABCDs for clinical diagnosis of melanoma, for example, a small macule may not be strikingly asymmetrical, the borders of it may not be scalloped or notched, and the morphologic features of it alone may be sufficient to enable diagnosis to be made correctly even when it is less than 6 mm in diameter. The statement, however, that "irregular color is always significant and perhaps should come first in any education guide" simply is not correct; many macules of melanoma are not strikingly variegate and, in reverse, some acquired nevi, such as Clark's nevi and Spitz's nevi, and some congenital nevi, such as congenital speckled lentiginous nevus (nevus spilus) and certain garment nevi may be variegate in color. In short, a constellation of criteria, and hardly ever a single criterion, leads to accurate clinical diagnosis of melanoma, especially lesions of it are small and flat.
 
The mnemonic proposed by Moynihan is much more seriously flawed than the ABCDs. Color is not the most important criterion, especially when red, white, and blue (referred to ludicrously as "the flag sign") are mentioned among the colors expected. Contour is merely a synonym for "border irregularity," and change is not something that a morphologist can recognize when assessing a particular pigmented lesion in a particular patient at a particular moment in time. In short, "the three C's of melanoma" are even less effective for diagnosis than the simplistic ABCDs.