In a case study published online on March 2 in JAMA Dermatology, Geller et al examined the relationship between total nevi, atypical nevi, and melanoma thickness. The study included 566 patients with melanoma. They were administered written surveys and underwent skin examinations at academic centers in Michigan and California within 3 months of diagnosis, measuring current total nevus count and atypical nevus count in addition to cataloguing melanoma thickness, histologic subtype, patient age, sex, marital status, skin self-examination and physician skin examination tendency, other health care visits, and mode of melanoma discovery.
Many epidemiologic trends were noted, but in summary, most melanoma patients had 0 to 20 total nevi (66.4%) and no atypical nevi (73.3%), a trend most pronounced in older patients (≥60 years). In patients younger than 60 years, higher nevus count (>50) was associated with thinner melanomas (≤2.0 mm), and the presence of more than 5 atypical nevi was associated with thicker melanomas (>2.0 mm).
What’s the issue?Studies clarifying the overall clinical characteristics of patients with aggressive melanomas appear every month in reputable journals, touting that concurrent total nevus count is important; or nevus size is important; or atypia is important; or clinical stigmata, medical history, and family history are important. Who is correct? Is everyone correct? On the pathology arm of the argument, Rosendahl et al (J Am Acad Dermatol. 2015;73:507-512) highlighted the same dilemma in which clinicians do not agree on the histopathologic features of nevi that consistently put patients at risk for individual lesion or de novo melanoma.
For me, each clinic day involves performing many total-body skin examinations, and many of these patients have innumerable nevi and various scars from lesions removed over the years with “atypical mole,” “premelanoma,” “precancer,” and various other self-reported labels. Some lesions may have documented pathology reports, but many do not. Some reports refer to dysplasia as a gradient, some do not. Some reports include molecular testing or clinical markers to grade lesions, and each can vary between institutions and pathologists. On the macroscopic level, clinically atypical nevi do not have a widely agreed upon set of criteria or threshold for biopsy; some clinicians use dermoscopic markers, and others utilize some version of the ABCDE (a=asymmetry; b=border; c=color; d=diameter; e=evolving) features.
The Geller et al study supports that these melanoma patients did not necessarily have more total nevi, and younger patients with aggressive melanoma may have a tendency toward more clinically atypical nevi. Although the study establishes what those institutions and clinicians determined to be atypical, I’m not sure that this is something that most clinicians widely agree upon. Additionally, these features were not paired with histopathologic dysplasia because the lesions were not biopsied.
What I find in conversation with colleagues is that some agree with what Geller et al defined as atypical, but some clinicians do not even refer to nevi as clinically atypical in a medical record unless they have pathology evidence of atypia (or the term their pathologist may use), which may be to avoid controversy regarding legal implications of atypia or “open-note” misunderstanding that the patient may have about this term, likening it to Papanicolaou test premalignancy verbiage.
I am not aware of one dermatologist or dermatopathologist who does not find this quandary to be frustrating. How do any of us really know which patients to follow more often for melanoma surveillance? How does your practice or institution report atypia in the clinical and histopathologic setting, and what do you find are the most important markers for development of melanoma?