A Digital Dermoscopy Follow-up Illustration and a Histopathologic Correlation for Angulated Lines in Extrafacial Lentigo Maligna.

IMPORTANCE: The diagnosis of extrafacial lentigo maligna can be a challenge because the dermoscopic features are not well described. These features can share some of the criteria of superficial spreading melanoma and some of facial lentigo maligna; however, these features are often absent. A new dermoscopic pattern has recently been described as forming angulated lines.

OBSERVATIONS: We report 4 cases of extrafacial lentiginous lesions in 3 patients in whom straight angulated lines have been observed as the only key for diagnosis. This is the first time, to our knowledge, that these lines were seen in the follow-up by digital dermoscopy during a lapse time of a few months. This morphologic change led to the excision of the lesion. The pathologic diagnosis of lentigo maligna was established in each case. Moreover, a histologic correlation of these straight angulated lines is documented.

CONCLUSIONS AND RELEVANCE: Angulated lines could be considered as a new warning sign during the follow-up of extrafacial lentigo. More studies are required to establish the sensitivity and specificity of this newly described dermoscopic feature.