Proteus syndrome.

Proteus syndrome is a rare congenital disorder that is characterized by a wide variety of deformities including macrodactyly. Skin and soft tissue lesions are common; they may increase in size as the child develops and may assume tremendous proportions. The syndrome is often mistaken for other more commonly recognized conditions such as neurofibromatosis. Unlike neurofibromatosis, the soft tissue masses in Proteus syndrome are not nerve tumors but, rather, are hamartomas composed primarily of lipomatous tissue. The hand surgeon should be aware of this condition when evaluating a child with macrodactyly.