Bazex-Dupré-Christol syndrome: an ectodermal dysplasia with skin appendage neoplasms.

Bazex-Dupré-Christol syndrome is a rare X-linked genodermatosis characterized by early-onset nonmelanoma skin cancers, atrophoderma follicularis, hypotrichosis, hypohidrosis, and multiple milia. Its molecular basis remains unknown and nosologic classification is debated. We report a 5-year-old child presenting sparse hair, reduced sweating, ice-pick skin depressions of the dorsum of hands, facial and limb milia, perianal skin hyperpigmentation, and hyperpigmented papules of the axillae and neck. His mother showed similar features but lacked hair involvement. Histologic examination of a skin papule obtained from the index case revealed features consistent with trichoepithelioma. Our findings indicate that trichoepitheliomas are an early sign of Bazex-Dupré-Christol syndrome and may guide the diagnosis even before the development of basal cell carcinomas. The high frequency of hypotrichosis, hypohidrosis and dry skin in Bazex-Dupré-Christol syndrome indicates that it may be better classified as an ectodermal dysplasia. Comparison with other conditions combining features of ectodermal dysplasia and proneness to skin tumors suggests the involvement of a common pathogenic pathway implicated in both skin development and cancer.