Clinico-histopathological and dermoscopic features of Becker nevus: an analytical observational study from southwestern India

Abstract

Background: Becker nevus (BN), a common nevoid hamartoma, presents as a hypermelanotic often hypertrichotic plaque localized to the chest, shoulder, or back in the first two decades of life. Aims: The aim of the study was to evaluate clinicohistopathological and dermoscopic findings of BN in the Indian population. Methods: Thirty-five clinically diagnosed cases of BN were enrolled. Sample characteristics, clinicohistopathological findings, dermoscopic findings, and developmental abnormalities were noted and an observational analytical study was carried out. Results: The mean age of the patients was 18.9 years and 28 (80%) were Males. BN was present since birth in 12 (34.3%), developed in the first decade in 5 (14.3%), and in the second decade in 18 (51.4%). Common sites included the chest in 10 (28.6%), the face in 8 (22.9%), and the upper limb in 7 (20%). Hypertrichosis was observed in 24 (68.6%) and acneiform lesions in 2 (5.7%). Twenty-two (62.9%) patients had right-sided lesions. No developmental abnormalities were detected. Skin biopsy findings included hyperkeratosis in 25 (71.4%), acanthosis in 32 (91.4%), elongation of rete ridges in 32 (91.4%), basal layer pigmentation in 35 (100%), and smooth muscle hyperplasia in 4 (11.1%) patients. Dermoscopic findings included reticular brown lines (pigmentation network) in 32 (91.4%), perifollicular white color (perifollicular hypopigmentation) in 27 (77.1%), skin furrow hypopigmentation in 17 (48.6%), and focal hypopigmentation in 15 (48.6%) cases. Conclusions: Onset at birth and facial lesions are common in those of Indian ethnicity, while developmental abnormalities associated with BN are infrequent.