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Dermatopathology: Practical & Conceptual July - September 1996
Lessons of History: Dysplastic Nevus: Atypical Mole or Monumental Myth? Part II
A. Bernard Ackerman, MD
Timothy A. Nielsen, MD
Daniela Massi, MD
Archives of Dermatology, 1978
Comments regarding images
Pathology of Malignant Melanoma, 1981
Human Pathology, 1984
Archives of Dermatology, 1978
Origin of Familial Malignant Melanomas from Heritable Melanocytic Lesions: The B-K Mole Syndrome. Clark WH Jr, Reimer RR, Greene MH, Ainsworth AM, and Mastrangelo MJ. Archive of Dermatology. 1978;114:73238.
"Distinctive melanocytic moles are described in 37 patients from six melanoma families. Among the family members examined by the authors, 15 of 17 patients with melanoma and 22 of 41 nonmelanoma relatives had the unique moles. The clinical and histological features of these moles have been designated the "B-K mole syndrome." The clinical features of the syndrome include the presence of <10 to > 100 moles prominent on the upper trunk and extremities, and variability of mole size (5 mm to 15 mm), outline, and color combination. Histologically, B-K moles show atypical melanocytic hyperplasia, lymphocytic infiltration, delicate fibroplasia, and new blood vessels that occur within a compound nevus or de novo. The transformation of two B-K moles into malignant melanomas was documented photographically." (
Although Clark and co-workers had written about "precursor lesions" of melanoma earlier in 1978,
the article, the abstract of which was just quoted, became the landmark because it was more comprehensive, illustrated the clinical lesions more fully, and displayed photomicrographs more richly than the previous ones* (
). Clark and co-workers named the precursor lesion B-K mole based on the last names of two patients in their study of kindreds with familial melanoma. As the title of the article communicates, the concept of a B-K mole, known soon thereafter as dysplastic nevus (DN), was an outgrowth of study of persons who had a compelling family history of melanoma.
Fig. 1 Archives of Dermatology, 1978.
Clark et al.:
"The combination of clinical appearance and histologic features of certain cutaneous pigmented lesions forms what we have called the B-K mole syndrome."
The morphologic attributes pictured verbally and graphically by Clark and co-workers do not constitute a syndrome. A syndrome, according to Webster's dictionary, is "a group of signs and symptoms that occur together and characterize a particular abnormality." What Clark et al. described is a single abnormality, to wit, the presence of a type of melanocytic nevus.
Clark et al.:
"We histologically examined at least one B-K mole in 15 of the 17 melanoma patients examined, and 22 of the 41 non-melanoma relatives examined. In most patients, we examined three or more B-K moles by serial paraffin blocks and hematoxylin-eosin stains. The B-K mole syndrome was not diagnosed without histologic confirmation."
The implication of these lines is that a single proven B-K mole is sufficient for diagnosis of the "B-K mole syndrome." Throughout their article, the authors make a distinction between the large moles (B-K) that they biopsied and the small ones (common or ordinary acquired), that they did not biopsy. The sentences just quoted attest to that and findings in
(their Figures 26) provide further evidence of that, showing as it does numerous pigmented lesions on the trunk, only the largest ("funny looking moles") of which were circled prior to biopsy. Furthermore, the authors never mentioned performing a single biopsy of a nevus other than a B-K mole. Only in 1979 did Clark's group biopsy what they considered to be common acquired moles (CAN) and found histopathologic changes like those in B-K moles. This led them to publish, in 1980, a concept of "sporadic" and "familial" types of DN and ideas about shrinkage in purported size of DN. In sum, Clark and co-workers at first did not compare and contrast the histopathologic findings in B-K moles and CAN. They made assumptions about the latter, but did not confirm those suppositions by study histopathogically of sections from biopsy specimens taken of them. In short, Clark and collaborators, from the outset, did not formulate repeatable, verifiable criteria for clinical or histopathologic diagnosis of either CAN or DN. Without such criteria, their entire construct lacks foundation.
Fig. 2 (original Figs. 26). All of the nevi pictured in these photographs, both those that are circled and those that are not, represent a single particular type of acquired melanocytic nevus that we name for Wallace H. Clark, Jr., i.e., Clark's nevus.
* A footnote of possible historical interest merits mention. According to Wallace H. Clark, Jr. in a telephone conversation with A. Bernard Ackerman in the summer of 1977, the manuscript of what eventually was to appear as an article in the Archives of Dermatology in 1978 had been rejected by several other journals, including the New England Journal of Medicine. Clark was upset about those rejections and did not know then, or until now, that at that very moment his manuscript was in the hands of Ackerman who had been chosen to review it by the Editor of the Archives of Dermatology. Ackerman's initial reaction upon reading the article was to reject it, but decided to show it to B. Allen Flaxman, a respected colleague, then engaged in basic science research at Woods Hole, Massachusetts, during a visit with him that summer. Flaxman's response was negative, too, and for similar reasons that pertained to fundamental flaws in logic. Ackerman decided, however, on reflection, to advise several points of clarification that, if incorporated, would make the manuscript acceptable for publication in the Archives. The proposals were accepted and the article was published.
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