A seven-year-old boy presented with complaint of a bald, elevated and symptomless patch on his scalp since birth. On examination, single big plaque (7.0 cm × 5.0 cm) was present on right frontoprietal region of the scalp. It was hairless and yellow orange in colour with clearly defined margins and pebbly and velvety surface (Fig. 1). General physical examination and routine laboratory parameters were unremarkable. The diagnosis of naevus sebaceous was made on clinical ground.

Sebaceous naevi are epidermal hamartomas, with sebaceous differentiation, occur in about 0.3% of all neonates. They comprise circum-scribed, slightly raised, pinkish, yellow, orange or tan plaques, with velvety surface. The sex incidence is equal.

Fig. 1. Scalp showing yellow-orange plaque with defined margins and velvety surface.

Lesions, round, oval or linear, vary in length from under 1 cm to over 10 cm. Most commonly occur singly, usually on the scalp and neck and less frequently on the face. On scalp they are devoid of hair. Malignant transformation usually occurs in middle age. The lifetime risk of malignant transformation is less than 5%. The most common malignancy is basal cell carcinoma; most being low-grade malignancy.

Diagnosis is usually straightforward on clinical grounds alone. In early infancy, lesions in the scalp must be distinguished from aplasia cutis, syringocystadenoma papilliferum, early juvenile xanthogranulomas and solitary mastocytoma. Histological examination is confirmatory.

Removal during childhood may be necessary for cosmetic reasons and is also justified on grounds of risk of malignancy. Excision with primary closure gives an excellent cosmetic result and generally adequate even in the presence of histological malignancy. Larger lesions may require tissue expansion.