Amelanotic/Hypomelanotic melanoma--is dermatoscopy useful for diagnosis?

Amelanotic/hypomelanotic melanoma often leads to delayed clinical diagnosis because its clinical appearance can mimic other hypopigmented skin conditions. Dermatoscopy (dermoscopy, epiluminescence microscopy) is thought to be a helpful diagnostic tool in pigmented skin lesions, but it can be used also in non-pigmented skin tumors due to the recognition of vascular structures not visible to the naked eye.

7 amelanotic/hypomelanotic melanomas in 6 patients were analyzed in order to define their dermatoscopic findings using standard pattern analysis.

Clinical and dermoscopic images of each lesion were obtained using Dermaphot (Heine Optotechnik, Herrsching, Germany), with 10-fold magnification of the lesion and the color slides were converted to digital format using a Kodak Photo CD system.

All 7 amelanotic/hypomelanotic melanomas revealed peculiar dermatoscopic findings, namely, atypical vessels, dotted vessels, and a central pink to white veil. In addition, in 2 patients a slight brownish homogenous pigmentation at the periphery of the lesion was observed. In one case the correct diagnosis was done by an experienced dermatologist using dermatoscopy, whereas in the remaining 6 cases the clinical diagnoses included squamous cell carcinoma, Bowen disease, pyogenic granuloma and basal cell carcinoma. In 2 of 6 patients amelanotic/hypomelanotic melanoma was associated with a previous history of melanoma.

Amelanotic/hypomelanotic melanoma exhibits as a common dermatoscopic denominator atypical vessels, varying in size and shape, usually associated with a central pink to white veil.