Asymmetric, disproportionate craniofacial hyperostoses of mosaic pattern in a patient not meeting Proteus syndrome criteria.

A 34-year-old patient with asymmetric hyperostosis of the craniofacial skeleton much more pronounced on the right side is presented. A long-term follow-up of 16 years showed progression of overgrowth even after skeletal maturity and despite repeated surgical corrections focusing on regional reduction of the hyperostoses. Clinical situation during infancy, adolescence, and adulthood is documented. Although the craniofacial hyperostosis in the patient was indicative of the Proteus syndrome, the applicable criteria were not met. Proportionate mild hemihypertrophia/hyperplasia of the patient's right extremities also exclude an oligosymptomatic variant of the Proteus syndrome limited to the skull. Both surgical strategies and difficulty of a diagnostic classification are discussed.