Linear forehead lesion

A 15-year-old male presented with an asymptomatic, dark-colored lesion over the forehead since birth. The lesion was first noted in the middle of both eyebrows, which then progressed in a linear pattern in an upward direction along the midline of the forehead over 10–15 years. There was no history of seizures, developmental delay, or systemic complaints. Neurological, skeletal, and ophthalmological examinations were unremarkable. The patient demonstrated age-appropriate cognitive development and satisfactory academic performance. Cutaneous examination revealed a linear, dark brown to black-colored verrucous plaque extending from the glabella to the upper forehead [Figure 1a]. There was no bleeding or ulceration from the lesion. Polarized dermoscopy revealed a cerebriform pattern interspersed with white thick scales and brown circular structures [Figure 1b]. Histopathology from the verrucous plaque showed hyperkeratosis, papillomatosis, increased basal layer pigmentation, and elongated rete ridges [Figure 2a-b]. Based on the clinical findings, dermoscopy, and histopathology features, the final diagnosis of linear verrucous epidermal nevus (VEN) was established.

Close

Figure 1:

(a) Hyperpigmented verrucous plaque over the glabella extending upward linearly over the forehead. (b) Dermoscopy showing cerebriform pattern, thick scales (black arrow) and whitish lines (blue arrow).

Export to PPT

Close

Figure 2:

(a) Histopathology on scanner view showing epidermal changes with unremarkable dermis, Hematoxylin and Eosin (H & E, ×100), (b) higher magnification showing hyperkeratosis (blue), papillomatosis with pigmented basal cell layer (red) (H & E, ×400).

Export to PPT

VEN is a benign keratinocytic hamartoma typically present at birth or arising in early childhood and is attributed to postzygotic somatic mosaic mutations. While generally isolated, VEN can be associated with systemic anomalies including skeletal deformities (e.g., scoliosis, limb length discrepancies), ocular abnormalities (e.g., colobomas, epibulbar dermoids), and neurological involvement (e.g., seizures, intellectual disability), collectively referred to as epidermal nevus syndrome.^[1] Diagnosis is primarily clinical; however, dermoscopy can serve as a valuable non-invasive adjunct in differentiating VEN from other pigmented or verrucous nevi, potentially obviating the need for skin biopsy. The various dermoscopic features include brown circles, branched thick curve lines, brown globules surrounded by a white halo, white exophytic papillary projections, brown dots, comedo-like openings, cerebriform structures, terminal hairs, and fine scaling.^[2] Occasionally, it may show different vascular patterns.^[2] The close differential diagnosis of VEN includes inflammatory linear VEN, linear lichen planus, verruca vulgaris, nevus sebaceus, nevoid acanthosis nigricans (AN), etc. [Table 1]. The available treatment options for VEN that have been mentioned in the literature include: 5-fluorouracil, tretinoin, podophyllin, cryotherapy, lasers (ablative CO₂ lasers, erbium Yaag lasers, etc.), electrosurgery, chemical peels, photodynamic therapy, and serial surgical excision and grafting. The parents were counselled regarding the benign nature of the lesion and its management options. Referral to a plastic surgeon was made for consideration of surgical excision. Facial VEN can mimic closely with nevoid AN over the face; hence, differentiating it from its closest mimickers is crucial, and dermoscopy acts as a handy adjunctive tool to narrow down the differentials.