Introduction Dermoscopic features Characteristic lesions Histology
Asymmetrical pigmented follicular openings are curved or crescent-shaped areas of pigment partially surrounding the adnexal openings of the face.
Asymmetrical pigmented follicular openings are seen through the dermatoscope as pigmented crescents at the periphery of a follicle. They can be the same colour as the surrounding pigment as in a solar lentigo, or heavily pigmented, often with a greyish hue as seen in lentigo maligna melanoma [1].
Asymmetrical pigmented follicular openings are characteristic of:
They can also occur in:
Although asymmetrical pigmented follicular openings are often said to be a clue to melanoma in situ, the clue actually has poor specificity [2].
Asymmetrical pigmented follicular openings are due to abnormal melanophages spread asymmetrically up the hair follicle. In lentigo maligna, abnormal melanocytes may arise from stem cells in the follicular infundibulum.
