A Highly Unusual Clinical Presentation and Imaging Appearance of a Rare Diseases: Melorheostosis.

Introduction: Melorheostosis, on its own, is an extremely uncommon disease. It is non-hereditary, sclerosing bone lesion affecting the adjacent soft tissues. Long bones are commonly involved. About 50% of the cases are evident before 20 years of age. It is gradually progressive and involves the adjacent soft tissues resulting in pain, fibrosis, joint contractures, and limb length discrepancies. Various forms of clinical presentation such as hemimelic, monomelic, mono-ostotic, and polyostotic have been described in the literature. Similarly there are different radiological varients like classical, osteoma , osteopathic striatae , and myositis ossificans.. Treatment is mainly palliative.

Case Report: We describe a highly unusual and extensive involvement of the lower limb in a Melorheostotic patient of 35 years of age with a deformity and limb length discrepancy. X-rays are like that of myositis ossificans and mixed type of pattern with extensive involvement from the pelvis to the toe. There is also intra-articular extension of melorheostosis mimicking synovial chondromatosis. The patient is in our close follow-up and physiotherapy guidance. Such an extensive involvement, along with para-articular and intra-articular involvement, is very rare.

Conclusion: Melorheostosis can extensively involve the whole of the limb right from the pelvis to the digits. It can also extend into the joints producing intra-articular loose bodies. Para-articular soft-tissue masses are also common. Radiologically, it can have a mixture of patterns described in the literature. Close follow-up of the patient is essential so as to provide palliative treatment, deal with the deformities, and to assess the progression of the diseases.