Melorheostosis: a review of 23 cases.

The aim of this study was to review clinical and radiological signs of melorheostosis in a large series of cases. Family history, patient history, clinical data and radiological features of 23 consecutive cases of melorheostosis were investigated. Criteria for establishing the diagnosis "melorheostosis" were defined. Sixteen patients (mean age 34 years, equal ratio between genders) had chronic pain in the affected limb(s) and/or subcutaneous fibrosis and/or various skin lesions. Number of involved bones: one bone (n = 10); two bones (n = 4); three or more bones (n = 9). Anatomic distribution: upper extremity (n = 5); lower extremity (n = 16); upper and lower extremity (n = 1); sacrum (n = 1). Radiologic pattern: osteoma-like (n = 7); classic candle wax appearance (n = 5); myositis ossificans-like (n = 1); osteopathia striata-like (n = 6); mixed pattern (n = 4). Patterns different from the appearance formerly judged to be "classic" prevail. The standard concept of disease manifestation has to be adjusted. Pathogenesis remains unclear. The classic theory claims the presence of an early embryonic infection of a sensory nerve inducing changes in the respective sclerotome, but we propose the concept of mosaicism as a better explanation for the sporadic occurrence, the asymmetric "segmental" pattern with variable extent of involvement and equal gender ratio of the disease.