A Typical Manifestation of Birthmark-Becker's Nevus Syndrome.

Full born term male baby having hyperpigmentation over back of neck and back of chest. The colour of nevus is black coloured. Hyperpigmented area is slightly hypertrophy. Imaging, X-ray spine, X-ray fingers and toes, X-ray chest, ultrasound of abdomen, CT scan of brain-normal. Treatment advised: Pigmentation can be reduced by pigment laser.

INTRODUCTION

Becker nevus is also called as Becker melanosis. It is a birthmark occurring mostly in males. It is due to an overgrowth of the epidermis (upper layer of the skin) pigment cells (clonocytes) and hair follicles. It is found on the shoulders, upper trunk, or occasionally, elsewhere [Figures 1 and 2]. It was first documented in 1948 by an American dermatologist, Samuel William Becker (1894-1964). Becker nevus syndrome is a rare type of epidermal nevus syndrome. It is a birth mark. There may be some abnormality of the underlying tissues derived from the same embryonic cell type, the ectoderm.[1] It is very rare. It is thought that it is caused due to a gene defect, which has not yet been identified. It may be triggered to develop by the circulating androgens (male hormones such as testosterone), which is why it appears in males. The main complication is malignant melanoma. Pigmentation can be reduced by a pigment laser. It is rare birth mark.

Figure 1

Just new born baby showing nevus at neck and shoulder

Figure 2

Just new born baby showing nevus at back of trunk

There may be some abnormalities of the underlying tissues derived from the same embryonic cell type, the ectoderm.[1]

Although the majority of the published cases of Becker nevus syndrome are sporadic, familial grouping can be observed very rarely,[2] probably due to a predominant inheritance[3] phenomenon. It is assumed to be caused by to a post-zygotic autosomal lethal mutation that survives in a mosaic form; in fact, Becker nevus usually presents as a pattern of mosaicism, either as a patch with serrated borders, or less frequently, as a segmental or “flag-like” lesion.

A new-born, full-term male baby was admitted in the Kamla Raja hospital, G.R Medical College, Gwalior, M.P., India with hyperpigmentation over back of the neck and of chest. The color of the nevus was blacked and it was hyperpigmented. On examination, the hyperpigmented area was slightly hypertrophic (raised). All systems and imaging were found to be normal.