False 'Melanocytic' Parameters Shown by Pigmented Seborrheic Keratoses: A Finding Which is not Uncommon in Dermoscopy.

摘要

BACKGROUND: Dermoscopic evaluation of pigmented lesions includes assessment of criteria suggestive of melanocytic proliferation. Dermoscopic diagnosis may be hampered when a nonmelanocytic lesion displays one or more melanocytic features. OBJECTIVE: To evaluate the incidence of misleading dermoscopic features characteristic of melanocytic lesions in pigmented seborrheic keratosis (PSK). METHODS: We evaluated 402 clinically typical PSKs from 138 patients with at least one clinically identifiable PSK. RESULTS: Approximately 10% of PSKs displayed one or more melanocytic features, the most frequent being a "false" pigment network. CONCLUSION: The occurrence of a "false" pigment network in PSK can be misleading in the differential diagnosis of clinically equivocal lesions. A correct diagnosis can only be obtained if all available dermoscopic criteria are appropriately assessed together with the clinical examination.