Dermoscopy of desmoplastic melanoma: report of six cases

Desmoplastic melanoma (DM) is a rare variant of cutaneous melanoma. Its diagnosis is often delayed by an unusual clinical presentation. The dermoscopic features of DM have not yet been described.

To define the dermoscopic features of DM. Patients and methods A single-institution register-based retrospective study of six cases of histology-proven desmoplastic melanoma for which dermoscopy data were available. The criteria we studied included: network, dots and globules, streaks, regression features, ulceration, number of colours, blue/white veil, and vascular pattern.

Only three cases exhibited one classical feature for a melanocytic lesion; other cases were recognized on the basis of the presence of figures of regression (all six), i.e. white scar-like areas and 'peppering' (three of six), multiple (> 4) colours (five of six), and of melanoma-related vascular patterns (five) such as linear-irregular vessels (four) and milky-red areas (two).

We believe that dermoscopy could help in the accurate diagnosis of this rare neoplasm. In the absence of a pigmented network, attention should be given to the identification of features of regression and to melanoma-associated vascular patterns.