nevus sebaceous (organoid nevus)

Introduction

Congenital malformation of sebaceous gland differentiation on the scalp or rarely on the face.

Pathology

• papillomatous epidermal hyperplasia with large numbers of mature sebaceous glands (case report of cerebroform nevus sebaceous)
• may be part of a complex syndrome that includes skeletal, ocular, & neurologic abnormalities
• risk of malignant transformation (basal cell carcinoma)

Genetics

• mosaic genetic mutations in the HRAS & KRAS genes

Clinical manifestations

• hairless, thin, elevated 1-2 cm plaque orange in color

Complications

10% of patients develop basal cell carcinoma

Management

• surgical excision timed around & prior to puberty for cosmetic reasons & to prevent development of basal cell carcinoma

More general terms

• nevus