Melorheostosis of the Right Lower Limb Presenting as Progressive Painful Swelling in a Young Adult: A Case Report.

Introduction: Melorheostosis is a rare, sporadic sclerosing bone dysplasia characterized by cortical hyperostosis with the classical "dripping candle wax" appearance on radiographs. It predominantly affects long bones of the appendicular skeleton and may mimic neoplastic or inflammatory bone disorders, creating diagnostic challenges. Case Report: A 28-year-old male presented with progressive pain and diffuse swelling of the right lower limb for 2 months. Examination revealed a hard swelling extending from the knee to the foot, fixed to the underlying bone with preserved joint mobility and no inflammatory signs. Radiographs demonstrated irregular cortical hyperostosis along the tibial shaft with the characteristic "dripping candle wax" appearance, with additional sclerotic involvement of the distal femur and multiple tarsal bones. Bone scintigraphy showed increased tracer uptake in the affected regions, whereas magnetic resonance imaging revealed cortical thickening without aggressive periosteal reaction or soft-tissue mass. Histopathology confirmed dense lamellar bone with osteoblastic rimming and no evidence of malignancy. A diagnosis of polyostotic melorheostosis was established. The patient was managed conservatively with analgesics and remained clinically stable with symptomatic improvement on follow-up. Conclusion: Polyostotic melorheostosis should be considered in patients presenting with unilateral limb pain and cortical hyperostosis. Recognition of the characteristic radiographic appearance is critical for accurate diagnosis and to avoid unnecessary invasive or aggressive treatment.