Trichoblastoma and syringocystadenoma papilliferum arising in naevus sebaceous in a 4-year-old boy.

摘要

Naevus sebaceous (NS) often shows the development of secondary tumours. The most common benign growth is syringocystadenoma papilliferum and trichoblastoma, while basal cell carcinoma (BCC) is the most frequent malignancy. Secondary tumours usually occur after puberty in NS but rarely occur in children. The youngest patient documented to date is a 7-year-old, who developed BCC in a NS lesion.2 We report trichoblastoma and syringocystadenoma papilliferum arising from a NS in a 4-year-old boy. A 4-year-old boy had a yellowish verrucous plaque on the left cheek since birth. The plaque gradually became larger as the patient grew. Biopsy exhibited a slightly thickened epidermis with a few small, immature sebaceous glands, and several apocrine glands. In addition, clusters of germinative follicular cells and small clusters of sebocytes originated from the under surface of the epidermis. Fibrotic stroma surrounded the clusters of primitive follicular cells. These findings were consistent with NS with trichoblastoma (Fig. 1a).