Becker's naevus of the lower limb

Follicular Becker's Nevus: A Case Report of an Uncommon Clinical Variant

Pigmented hairy epidermal nevus, also known as Becker's nevus, has a typical description as a unilateral, hairy in appearance, light to dark brown patch with an irregular but clearly defined border. However, the exact aetiopathogenesis is still poorly comprehended. We report the case of a 19-year-old female who presented with asymptomatic brownish-pigmented macular lesions on the right breast that had slowly increased in size over the past three years. Upon cutaneous inspection, the right breast had 3-5 mm rounded and oval perifollicular macules that ranged from light to dark brown hue without increased hair growth. The macules were discrete and in no particular pattern. Dermoscopy of the lesions showed well-defined perifollicular hypopigmentation surrounded by a pigmented network-like pattern. Histopathology of a punch biopsy taken from one of the follicular lesions demonstrated an increase in basal layer pigmentation with elongation of rete ridges and acanthosis, consistent with Becker's nevus. The patient underwent three sittings of diode laser therapy, once in four weeks, with slight improvement in pigmentation.

Follicular Becker's Nevus: A New Clinical Variant

Becker's nevus, also known as pigmented hairy epidermal nevus, is characteristically described as a unilateral, hairy, light to dark brown macule with sharply outlined but irregular border. The etiopathogenesis of Becker's nevus is still not clearly understood. Perifollicular pigmentation has been described earlier by some authors. But, Becker's nevus presenting exclusively with follicular lesions has not been described. We are reporting a series of patients of Becker's nevus with follicular lesions. The diagnosis in all the patients was made after clinicopathological correlation. Follicular epithelium may hold a significant role in the etiopathogenesis of Becker's nevus.

Becker nevus on the lower limb: case report and review of the literature

BACKGROUND

Becker nevus is a hamartoma with brown hyperpigmentation and hypertrichosis that usually affects young males. It has a predilection for the upper half of the trunk and proximal upper extremity.

OBJECTIVE

This is a case report of a 38-year-old male with a Becker nevus without hypertrichosis on the lower limb and a review of the literature.

RESULTS

Including our case report, 12 cases of Becker nevus on the lower limb were identified in the English literature (8 males and 4 females). It has never been reported below the knee. In males, the lesion was not associated with other anomalies, and all but two showed hypertrichosis (six of eight). In 50% (two of four) of women, it was associated with localized lipoatrophy. In one woman, it presented without hypertrichosis.

CONCLUSION

The presence of Becker nevi on the lower limb is unusual, and hypertrichosis is not always a feature. Larger studies are required to look into the true prevalence of this presentation and its prognostic value as a marker for other anomalies.