Exogenous pigmentation of the sole mimicking in situ acral melanoma on dermoscopy

The parallel ridge pattern, characterized by a parallel band-like pigmentation of the ridges of the surface skin markings, re-presents the most important dermoscopic feature of in situ acral melanoma. A case of a young girl who showed a plantar pigmented brown macule likely due to prolonged contact with black rubber shoes, revealing a parallel ridge pattern on der-moscopy, is reported and discussed. Although parallel ridge pattern is highly suspicious of early melanoma, exogenous pig-mentation should be considered as differential diagnosis in case of rapid onset acral pigmented macules.