Clinical and dermoscopic features of atypical Spitz tumors: A multicenter, retrospective, case-control study

Few studies have described the clinical and dermoscopic features of atypical Spitz tumors. Objective—To describe the clinical and dermoscopic features of a series of AST as compared to those of conventional Spitz nevi (SN). Multicenter, retrospective, case-control study, analyzing the clinical and dermoscopic characteristics of 55 AST and 110 SN that were excised and diagnosed histopathologically. Results—The majority of AST presented clinically as a plaque or nodule, dermoscopically typified by a multicomponent or nonspecific pattern. A proportion of lesions (16.4%) exhibited the typical non pigmented spitzoid pattern of dotted vessels and white lines under dermoscopy. Nodularity, ulceration, linear vessels, polymorphic vessels, white lines, and blue/white veil were associated with AST by univariate analysis, but only nodularity and white lines remained significant after multivariate analysis. In contrast, a pigmented typical spitzoid pattern was a potent predictor of SN, associated with 6.5-fold increased probability. Limitations—Differentiation from spitzoid melanoma and other non melanocytic lesions was not investigated. Conclusion—Atypical Spitz tumors are polymorphic melanocytic proliferations with a nodular clinical appearance. Dermoscopically they demonstrate a multicomponent and nonspecific pattern. A typical non pigmented spitzoid pattern on dermoscopy (with dotted vessels and white lines) does not exclude AST