Lentiginosis Within Plaques of Linear Atrophoderma of Moulin: A Twin-Spotting Phenomenon?

The document describes a rare case of Linear Atrophoderma of Moulin (LAM) with concurrent segmental and spotty lentiginosis in a 19-year-old patient, suggesting a potential twin-spotting phenomenon. LAM is characterized by hyperpigmented, atrophic skin lesions along Blaschko's lines. This case was notable for bilateral extensive LAM with lentiginosis within the lesions, a combination not previously reported. Histopathological findings included epidermal acanthosis, a hyperpigmented basal layer, and reduced elastic fibers in the papillary dermis. The co-occurrence of lentiginosis and LAM may indicate nonallelic twin spotting, but a coincidental relationship cannot be ruled out. This case adds to the understanding of LAM's clinical presentation and possible genetic origins.