# Case Report: Leathery black plaque on the temple and scalp

## TL;DR

A 13-year-old boy presented with a rare case of sebaceous nevus on his scalp and face, which was diagnosed and treated to prevent potential cancer.

## Contribution

This case report presents a rare presentation of sebaceous nevus with multiple verrucous plaques on the scalp and face.

## Key findings

- The patient had a hyperpigmented verrucous plaque on the scalp and face, diagnosed as sebaceous nevus.
- Dermoscopic examination showed cerebriform patterns and yellowish-gray globules, supporting the diagnosis.
- The case highlights the importance of early diagnosis to prevent malignant transformation.

## Abstract

Epidermal nevus sebaceous, commonly known as the nevus sebaceous of Jadassohn, is a congenital sebaceous hamartoma. It typically manifests as a single yellowish plaque across the head and neck and is composed of sebaceous glands. It commonly occurs during infancy and grows during puberty. Usually, it follows a benign course; however, in a few cases, it can be malignant. This is the case of a 13-year-old child with verrucous plaques on the temple and scalp.

We report the case of a 13-year-old boy with a steadily developing hyperpigmented verrucous plaque on the scalp and ipsilateral side of his face. A dermoscopic examination revealed ridges and fissures in a cerebriform pattern with yellowish-gray globules and a papillary appearance. Physical examination and laboratory tests revealed no abnormalities. Biopsies were taken from the scalp and temple area, and the findings were consistent with the diagnosis of nevus sebaceous. The patient was referred to a plastic surgeon for a staged excision.

We describe a unique example of a sebaceous nevus that affected the scalp and ipsilateral side of the face. As this hamartomatous growth carries the risk of cancer development, a dermatologist must identify the condition and begin treatment before malignant transformation occurs. This example of multiple verrucous plaques is an exception.