False "melanocytic" parameters shown by pigmented seborrheic keratoses: a finding which is not uncommon in dermoscopy.
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.


CONCLUSIONS
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.
De Giorgi
Vincenzo
V
Dipartimento di Scienze Dermatologiche and Patologia Umana ed Oncologia, Università degli Studi di Firenze, Firenze, Italy. vdegi@tin.it
Massi
Daniela
D
Stante
Marcello
M
Carli
Paolo
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D017492:Keratosis, Seborrheic / Q000473:pathology*; D008297:Male; D008545:Melanoma / Q000473:pathology; D008875:Middle Aged; D012878:Skin Neoplasms / Q000473:pathology