Macrodactyly in Proteus syndrome.

A case of Proteus syndrome in a 13-year-old boy with macrodactyly, hemihypertrophy, exostosis of the skull, epidermal naevi, palmar and plantar masses, and scoliosis is reported. Macrodactyly involving the left thumb was treated surgically. The usual findings in macrodactyly, hypertrophy of the digital nerves and proliferation of subcutaneous fat, were not observed in this case. Macrodactyly associated with Proteus syndrome should be distinguished from other forms of macrodactyly because of its poor prognosis and high rate of recurrence.