Abstract

Becker's melanosisis a cutaneous smooth muscle hamartoma characterized by a circumscribed hyperpigmented plaque with hypertrichosis. This is present since birth however become prominent during puberty. It is commoner in males. Here we report a rarer presentation of Becker’s melanosis in a 13 years old female conϔ‹”med with histopathology

Keywords

Hypertrichosis, Smooth muscle hamartoma, Becker’s melanosisc

Introduction

William Becker in 1949 described Becker’s Melanosis as “concurrent melanosis and hypertrichosis in the distribution of nevus unius lateris” [1]. Becker's melanosisis a cutaneous smooth muscle hamartoma characterized by a unilateral, circumscribed hyperpigmented plaque often with localized hypertrichosis that commonly affects the shoulder or trunk. Here we report a 13 year old female came with complaints of Hyperpigmentation over right forearm since the age of 4 years .she subsequently developed increased hair growth over the patch which on histopathology revealed Becker’s Nevus

Case Report

A 13-year-old female came with complaints of a pigmented patch over right forearm since the age of 4 years. The lesion initially started over right wrist joint which gradually progressed to involve the right forearm (more on the extensors surface). It was not associated with pain or itching. H/o increased hair growth over the lesion is present. Onexamination a hyperpigmented patch with irregular borders was present over right forearm extending from mid dorsum of the hand till the right elbow joint.

Figure 1:H and E section at low power showing mild epidermal acanthosis with increased pigmentation of basal cell layer. Dermis shows increased smooth muscle cells with eel like nucleus. Pilosebaceous unit see in the deep dermis.

Figure 2:Clinical image showing pigmented patch with irregular borders and localized hypertrichosis.

Discussion

Localized hypertrichosis was present. Punch biopsy was taken over the lesion (about 5cm below the elbow joint on extensor surface). Histopathological examination revealed mild acanthosis with elongation of rete ridges, increased pigmentation of basal layer of epidermis. Dermis shows increased number of smooth muscle cells having elongated eel shaped nucleus suggestive of a smooth muscle hamartoma.William Becker in 1949 described Becker’s Melanosis as “concurrent melanosis and hypertrichosis in the distribution of nevus unius lateris”. Becker's nevus is also called Becker's melanosis or Becker's pigmentary hamartoma [2]. It is a cutaneous smooth muscle hamartoma that presents as a circumscribed, hyperpigmented patch or plaque with hypertrichosis. Mostly they are sporadic in nature; however familial occurances have been reported [3]. It has traditionally thought to occur more commonly in males, but recent studies showed equal preponderance in males and female children [4]. It commonly manifests as solitary lesion that usually involves the upper trunk, scapular region, or upper arm unilaterally [5]. Becker’s Nevus is found to be androgen-dependent (increased androgen receptors have been found over the lesion) that partially explains it occurrence in male population. It becomes more prominent during adolescence with androgen influence .Nevus of Becker is pale initially and is often first noticed after an intense sun exposure episode. Becker’s nevus syndrome is a rare condition in which there are associated anomalies like ipsilateral breast hypoplasia, musculoskeletal abnormalities (eg, scolio-sis, ipsilateral limb hypoplasia), maxillofacial abnormalities, and additional cutaneous hypoplasias. Treatment as such is not required, but some patients opt for removal of pigment or hair on lesion for cosmetic purposes. In case of smaller lesions surgical excision can be done. Ablative 10,600-nm fractional CO₂ laser and hair removal laser therapy have been used with partial s. Laser hair removal can give the illusion of lightening the lesion. Long-pulsed and picosecond alexandrite laser, as well as quality- switched Nd: YAG, have been cited as useful in some studies, but the current evidence lacks statistical power and has inconsistent findings. Topical flutamide has also been used.

Conclusion

Becker’s melanosis is smooth muscle hamartoma that commonly manifests in males around puberty and mainly involves the upper trunk and scapular region. This case is being reported due to the rare presentation of Becker’s melanosis occurring over the forearm in a female patient which to our knowledge is the second such presentation being reported from our institution.

Acknowledgement

None

Conflict Of Interest

The authors declare that there is no conflict of interest.

References

1. Becker SW. Concurrent melanosis and hypertrichosis in distribution of nevus unius lateris. Arch Dermatol Syphilol. 1949; 60:155-160.
2. Naveen KN, Pai VV, Hegde S, et al. Beckerâ??s naevus on the forearm-A case report. Egypt Dermatol Online J. 2013; 9.
3. Book SE, Glass AT, Laude TA. Congenital Becker's nevus with a familial association. Pediat Dermatol. 1997; 14:373-375.
4. Patrizi A, Medri M, Raone B, et al. Clinical characteristics of Beckerâ??s nevus in children: Report of 118 cases from Italy. Pediat Dermatol. 2012; 29:571-574.
5. Ramot Y, Maly A, Zlotogorski A. A rare case of multiple Becker's nevi in a checkerboard mosaic pattern. J Eur Acad Dermatol Venereol: JEADV. 2014; 28:1573-1574.

Author Info

Sivaramakrishnan. S^*, Abhinesh, Vignesh N R and K. Manokaran

¹Department of DVL, Sree Balaji Medical College and Hospital, Bharath University, Chennai, Tamil Nadu, India

Received: 04-Oct-2021 Accepted: 18-Oct-2021 Published: 25-Oct-2021