Dermoscopy of pigmented poromas.

BACKGROUND: To date, little is known about the dermoscopic features of pigmented poromas.

METHODS: Twelve cases of pigmented poromas examined by dermoscopy at the Department of Dermatology, Shinshu University Hospital (Matsumoto, Japan), between January 2000 and February 2009 were collected. Retrospectively, digital dermoscopic images were evaluated for the presence of dermoscopic structures.

RESULTS: Vascular structures were observed in 8 of 12 cases. Hairpin vessels were found in 3 cases. Most were elongated and irregularly shaped. Polymorphous vessels were observed in 3 cases, of which 2 showed combinations of dotted vessels and linear-irregular vessels and 1 combinations of hairpin vessels and glomerular vessels. Arborizing vessels were observed in 2 cases. Globule-like structures occurred in 7 cases. Globule-like structures and arborizing vessels coexisted in 2 cases. Comedo-like openings were observed in 3 cases, all of which were accompanied by hairpin vessels.

CONCLUSIONS: Pigmented poromas mimic a number of skin tumors, including pigmented basal cell carcinomas, seborrheic keratosis and malignant melanoma, because they present various clinical, dermoscopic and histopathological features.