Becker's melanosis: A report of 12 cases with atypical presentation

Abstract

Becker's melanosis is a distinct clinical entity. It usually presents in adolescence as a unilateral, hyperpigmented, hairy cutaneous hamartoma. We report herein 12 cases of Becker's melanosis that differ in their presentation from classical Becker's melanosis, and we believe that such presentations are not uncommon.

Clinicopathological Features and Immunohistochemical Alterations of Keratinocyte Proliferation, Melanocyte Density, Smooth Muscle Hyperplasia and Nerve Fiber Distribution in Becker's Nevus

“…Although the diverse age may be a credible explanation for this difference34, no statistical difference of gender and diagnostic age in this study seems not to support this hypothesis. Furthermore, multiple papules within the lesion might be a clue to the clinical diagnosis of BN based on the present and previous observations48. On the other hand, we did not found positive family history, breast hypoplasia and increased prevalence of acne vulgaris, while the concomitance of neurofibromatosis type 1 in 2 cases may be interesting.…”

“…H&E stain demonstrates normal or increased number of melanocytes in BN810, while Dopa and immunohistochemical stain displays a significant increment211. We also found the incremental counts of Melan-A + melanocyte in the lesional and perilesional skin compared with normal skin.…”

“…Compared with the previous studies28, our results revealed the epidermal changes (elongated and fused rete ridges, keratotic plugging and basal pigmentation) were similar except acanthosis, but dermal alterations (mild perivascular lymphohistiocytic infiltration, fibrosis, and smooth muscle and sebaceous hyperplasia) were more common. Whether these histopathologic differences might be related to the diagnostic age, biopsied sites and judgement criteria, the rete ridge elongation and fusion and basal hyperpigmentation seems to be the typical features of BN28.…”

“…The diagnosis of BN mainly hinges on the clinical features, but histopathology may be sometimes necessary to differentiate from other pigmentary disorders such as melanocytic nevus, café-au-lait macules, congenital smooth muscle hamartoma and postinflammatory hyperpigmentation8. Compared with the previous studies28, our results revealed the epidermal changes (elongated and fused rete ridges, keratotic plugging and basal pigmentation) were similar except acanthosis, but dermal alterations (mild perivascular lymphohistiocytic infiltration, fibrosis, and smooth muscle and sebaceous hyperplasia) were more common.…”

A typical Becker′s nevus at an atypical site in a female child

“…In a case series, Becker's nevus was reported to occur at various atypical sites such as flank, pubic area, right arm, upper leg. [4] Becker's nevus rarely occurs in the lower limb. In a Jordanian survey done among males, they reported a prevalence of 6.5% of which only 1.1% of males showed localization of Becker's nevus over legs.…”