Melorheostosis (of Leriand Joanny) is a rare, non-genetic sclerotic dysplatic bone disorder presenting at any age, usually from late childhood to adulthood. Its aetiology is unknown. It affects mainly the long bones of the upper and lower limbs, but also the short bones of the hand and foot and, rarely, the axial skeleton. Onset is usually insidious, with pain, deformity of the extremity, limb stiffness and limitation of joint motion, as well as thickening and fibrosis of the overlying skin and muscle atrophy being the common clinical features found on presentation. In adults the characteristic radiographic appearance consists of irregular hyperostotic changes of the cortex, generally on one side of the bone, resembling melted wax dripping down one side of a candle, from which melorheostosis derives its name. This, however, is not a feature of the radiographic appearance in children, where the external cortical margin retains its regular outline. Children more often present with a discrepancy in limb size rather than with pain (as is seen in adults). We present our case of melorheostosis in a 12-year-old child to highlight the main clinical and radiological differences found between children and adults.

sclerosis; bone dysplasia; cortical hyperostosis; medullary encroachment; limb asymmetry; growth disturbances