Melorheostosis simulating bone tumor: Diagnostic challenges in a case report with literature review

Abstract

Melorheostosis is a rare skeletal dysplasia of uncertain etiology that predominantly affects the long bones; involvement of the hand and wrist is uncommon, with an incidence of 0.9–1/million. Although the condition classically demonstrates a “dripping candle wax” appearance on radiographs, atypical presentations may mimic other sclerotic bone disorders, creating diagnostic challenges. We report the case of a 35-year-old female who presented with pain and deformity in the right hand for 2 years. Clinical examination revealed tenderness over the thumb and index finger, with a restricted range of motion (ROM) and decreased grip strength. Radiographs demonstrated eccentric cortical thickening with a characteristic dripping-candle-wax appearance. Computed tomography and magnetic resonance imaging of the hand and wrist supported the diagnosis of melorheostosis. Bone scintigraphy showed increased tracer uptake around the thumb and index finger. Bone biopsy from the index finger revealed non-specific histopathological findings, including dead bone with adjacent fibrous tissue and fragments of mature lamellar bone. The patient was treated conservatively with intravenous zoledronic acid (4 mg diluted in 100 mL of normal saline) administered once monthly for 3 consecutive months, along with nonsteroidal anti-inflammatory drugs and physiotherapy, and showed relief of pain and no improvement in ROM at 20-month follow-up. This case highlights the diagnostic importance of multimodality imaging and emphasizes the role of a multidisciplinary approach in distinguishing melorheostosis from other sclerotic bone disorders.