Dermoscopic criteria identified for diagnosing melanoma in situ

(HealthDay)—The most frequent dermoscopic criteria for melanoma in situ (MIS) are regression, atypical network, and irregular dots and/or globules, according to a study published online Feb. 21 in JAMA Dermatology.

Aimilios Lallas, Ph.D., from Aristotle University in Thessaloniki, Greece, and colleagues conducted a diagnostic accuracy study with retrospective patient enrollment in three centers, including 1,285 individuals with histopathologically diagnosed MIS or other flat, pigmented skin tumors. Three independent investigators evaluated dermoscopic images of MIS and other flat pigmented skin tumors for the presence of predefined criteria.

The researchers found that 25.3 percent of the lesions were MIS. The most frequent dermoscopic criteria for MIS were regression, atypical network, and irregular dots and/or globules (92.9, 85.5, and 50.2 percent, respectively). Five main positive indicators of MIS were identified in multivariate analysis: atypical network, regression, irregular hyperpigmented areas, prominent skin markings, and angulated lines (3.7-, 4.7-, 5.4-, 3.4-, and 2.2-fold, respectively). Two of these criteria remained potent MIS indicators when compared with excised nevi: irregular hyperpigmented areas and prominent skin markings (4.3- and 2.7-fold, respectively).

"Clinicians should take into consideration the aforementioned dermoscopic indicators for the diagnosis of MIS," the authors write.