The Proteus syndrome involves asymmetrical gigantism, verrucous epidermal naevi, vascular malformations, hamartomas and hyperostosis. The clinical features have frequently been described, but the radiological features have not been studied in detail. This paper describes the radiological features of a group of 18 patients (12 male, 6 female) that presented to the Department of Dermatology and Orthopaedic Surgery of this institution.

Plain radiographs of each affected area were obtained to assist in the diagnosis and subsequent management of each patient. These radiographs were evaluated in an attempt to define the radiological anatomy of the osseous lesions.

The abnormalities were classified as involving abnormal ossification, hyperostotic overgrowth or ectopic calcification. The individual features of each group will be presented. We attempted to define radiological parameters that were specific to this condition and therefore useful in diagnosis. We considered a number of radiological measurements and found a consistent alteration in bony architecture of the upper and lower limbs of affected individuals. This association was not detected in other overgrowth symptoms. This is the first objective radiological parameter that assists in the diagnosis of this rare condition.