Melorheostosis of the Trapezium

We report a 56-year-old female with symptomatic protrusion of the bony lesion in the trapezium. Excision and biopsy of the bony lesion revealed thickened and sclerotic bony trabecula with adjacent zone of fibrocartilage, which is comparable with melorheostosis. This lesion with unique radiologic and histologic findings may be important to differentiate with other bony lesions such as myositis ossifications and osteosarcoma.