Extensive melorheostosis of the upper extremity: Evaluation of disease activity with 99mTc-MDP bone scintigraphy.

Melorheostosis is a rare, sporadic sclerosing bone dysplasia characterized by a "dripping candle wax" appearance on imaging. We report a case of a 29-year-old male with a 20-year progressive history of bone overgrowth and joint contracture in the left upper extremity. Technetium-99m-methylenediphosphonate (99mTc-MDP) bone scintigraphy demonstrated intense tracer uptake, indicating high metabolic activity despite the long-term disease course. Three-dimensional computed tomography (CT) reconstruction visualized extensive hyperostosis crossing multiple joints, while magnetic resonance imaging (MRI) revealed associated soft tissue involvement. The diagnosis was confirmed by biopsy. This case highlights the value of multimodality imaging in assessing the extent and activity of this rare condition to guide surgical intervention.