Progressive and extensive hypomelanosis and extensive pityriasis alba: same disease, different names?

JEADV 2006, 20, 1328–1399 © 2006 European Academy of Dermatology and Venereology 1363 diagnosis of pigmented skin lesions. By using the dermoscopic technique it is known that pigmented Spitz nevus on the non-glabrous skin exhibits certain characteristics. These are (1) a starburst pattern, characterized by a prominent, black to blue diffuse pigmentation and pseudopods regularly distributed at the periphery in a radiate pattern, and (2) a globular pattern, typified by a discrete, brown to grey-blue pigmentation and a peripheral rim of large brown globules, often extending throughout the entire lesion. The heavily pigmented nests of melanocytes closely packed along the dermo-epidermal junction represent the histopathological correlation of the starburst pattern. In contrast, the large nests of melanocytes within the epidermis and/or papillary dermis are consistent with the globular pattern seen in spindleand/or epithelioidcell naevi. Pizzichetta et al. reported a case of pigmented Spitz nevus on the dorsum of the first finger on his left hand that underwent careful dermoscopic follow-up. The globular pattern was recognized during initial examination, and the starburst pattern was identified on the same site 3 months later. They concluded that the two main dermoscopic aspects might be a different morphological expression corresponding to the evolutionally discrete phases of pigmented Spitz nevus. In the present case, dermoscopic study showed that a diffuse black pigmentation with a central depigmentation and a characteristic regular rim of black streaks was observed at the periphery in a radiate distribution. These findings are consistent with the starburst pattern seen in pigmented Spitz nevus on the non-glabrous skin. Thus, dermoscopy is a valuable tool for the diagnosis of pigmented Spitz nevus, even on the glabrous skin.