Egyptian Journal of Dermatology and Venerology

THROUGH THE DERMATOSCOPE
Year
: 2019  |  Volume : 39  |  Issue : 1  |  Page : 37--39

Dermatoscopy of Becker’s nevus


Pragya A Nair, Khushboo Modasia, Namrata Bhavsar, Radhika Navadiya 
 Department of Dermatology  Venereology, Pramukhswami Medical College, Karamsad, Gujarat, India

Correspondence Address:
Pragya A Nair
Department of Dermatology  Venereology, Pramukhswami Medical College, Karamsad 388325
India




How to cite this article:
Nair PA, Modasia K, Bhavsar N, Navadiya R. Dermatoscopy of Becker’s nevus.Egypt J Dermatol Venerol 2019;39:37-39


How to cite this URL:
Nair PA, Modasia K, Bhavsar N, Navadiya R. Dermatoscopy of Becker’s nevus. Egypt J Dermatol Venerol [serial online] 2019 [cited 2019 Aug 18 ];39:37-39
Available from: http://www.ejdv.eg.net/text.asp?2019/39/1/37/237843


Full Text



A 22-year-old healthy male presented with an asymptomatic hyperpigmented lesion over his left shoulder and upper arm. The lesion developed at the onset of puberty and became progressively darker since past 2 years. On examination, a well-demarcated brownish patch of ∼10×12 cm in size was present on the left shoulder extending to left arm with irregular borders ([Figure 1]). No hypertrichosis was noted on the lesion. There was absence of any other nevus elsewhere on the skin. No other congenital abnormality was detected. No hypertrichosis or café au lait spots were present elsewhere on the body. General examination and systemic examination revealed no abnormality. A clinical diagnosis of Becker’s nevi was made.{Figure 1}

Dermoscopy examination with DE-300 (Firefly) polarizing digital dermatoscope with ×20 magnification performed on the lesion demonstrated well-defined pigment network (red arrow), uniform thickness of lines, and uniform size and shape of network of pigmentation with perifollicular hypopigmentation (green arrow) ([Figure 2]).{Figure 2}

Histopathology revealed epidermal acanthosis along with regular elongation of rete ridges. Increased pigmentation of the basal layer was seen without increase in the number of melanocytes. Some melanophages were seen in the dermis ([Figure 3]). The diagnosis was confirmed histopathologically.{Figure 3}

Becker [1] first described a ‘concurrent melanosis and hypertrichosis in the distribution of nevus unius lateris’ which has since been termed Becker’s nevus.

Becker’s nevus is a cutaneous hamartoma that usually presents in late childhood or early adolescence. Clinically it presents with hyperpigmented patch that gradually evolves into a plaque and displays variable degree of hypertrichosis, that is, skin may thicken towards the center of the lesion and increased terminal hairs may appear on and around the lesion. It arises near the large joints especially shoulders, elbows, and hips. Once fully evolved, Becker’s nevus persists unchanged through life.

Becker’s nevus is not an uncommon condition, being reported in ∼2.1% of young men. Male to female ratio is reported to be 5 : 1. Androgenic pathogenesis of Becker’s nevus has been suggested based on its less frequent occurrence in females; moreover, hypertrichosis and hyperpigmentation are relatively less appreciable in affected women. Increased expression of androgen receptors and androgen receptor mRNA has been found in dermal fibroblasts of Becker’s nevus [2].

Becker’s nevi generally occur without any associated pathology, but several ipsilateral developmental abnormalities have been described, particularly breast hypoplasia, supernumerary nipples, aplasia of the pectoralis major muscle, limb reduction, segmental odontomaxillary dysplasia, and lipoatrophy. Spina bifida, scoliosis, pectus carinatum, congenital adrenal hyperplasia, and an accessory scrotum have also been reported [3].

Histopathological features of Becker’s nevi include epidermal acanthosis, regular elongation and fusion of rete ridges, hyperpigmentation of the basal layer, and hyperkeratosis, as well as dermal smooth muscle hyperplasia. It helps to differentiate it from its common mimics like congenital melanocytic nevus and café au lait macules (CALM).

Dermoscopy has gained an irreplaceable role in the clinical evaluation of skin diseases. It is a novel clinical tool that should be considered similar to the stethoscope of general practitioners. This office procedure may obviate the need for a skin biopsy for diagnosis and follow-up. Some dermoscopic patterns are observed consistently with certain diseases, and these then could be used for their diagnosis and will obviate the need for a skin biopsy, which potentially increases morbidity and costs. Dermoscopy seems to provide considerable diagnostic aid in differentiating Becker’s nevus from its differentials like congenital melanocytic nevus, CALM, and nevus spilus ([Table 1]). Dermoscopy can substitute biopsy in cosmetically important areas.{Table 1}

Although the diagnosis of Becker’s nevus is primarily clinical, it can be aided by dermoscopy. Pigment network, perifollicular and focal hypopigmentation, hypertrophic hair follicles, skin furrow, and vessels are the main dermoscopic features [5].

The dermoscopic findings in Becker’s nevus differ slightly between the center and the periphery of the lesion. In the center, there is prominent pigmentory network, blotchy hyperpigmentation with terminal hairs, and parafollicular hyperpigmentation whereas at the periphery of the lesion, there is normal pigmentory network with no hyperpigmentation, but with terminal hairs and parafollicular hyperpigmentation.

CALM present since birth or may appear later. It is found in 19% of normal individuals also. Color varies from light to dark brown with smooth or irregular borders. Giant CALM in patients of neurofibromatosis resembles Becker’s nevus. Histologically, increased pigmentation of basal layer and occasional presence of giant melanosomes characterize CALM. Dermoscopic findings are the same in the center and the periphery of the lesion, with focal thickening of pigmentory network and no hair follicles.

Lesions of Becker’s nevus are benign and asymptomatic, so no treatment is necessary. Patients should, however, be examined for associated noncutaneous abnormalities, and reassurance is all that is needed. Hyperpigmentation can be treated with Q-switched ruby and Erbium : YAG lasers with selective damage of superficial melanocytes, with some beneficial results. The hypertrichosis can be treated with depilation, a diode, or Nd : YAG laser [8].

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts on interest.

References

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