Sulcal-Gyral Pattern in the Scalp Fibrous Hamartoma of Infancy: A Case Report

Fibrous hamartoma of infancy (FHI) is a benign soft-tissue tumor that typically presents within the first two years of life. We report an eight-year-old boy with a long-standing, painless, left fronto-parietal scalp mass that enlarged over two years. Physical examination showed a 6×5×2 cm, firm, mobile, non-tender subcutaneous lesion with overlying hair. Magnetic resonance imaging (MRI) and contrast-enhanced computed tomography (CT) showed a subcutaneous, fat-containing mass without bony involvement and a sulcal-gyral surface pattern. The lesion, including overlying skin and thickened pericranium, was excised en bloc, and the defect closed with a rotational flap. Histopathology confirmed FHI, showing the characteristic triphasic composition of mature adipose tissue, fibrocollagenous fascicles, and primitive spindle-to-stellate cells in a myxoid stroma without atypia or necrosis. This case illustrates that FHI, although usually infantile and truncal, can occur on the scalp in older children, and that complete surgical excision is an effective management option.