A rare case of first metacarpal chondromyxoid fibroma

Chondromyxoid fibroma is a rare, benign, aggressive tumor of cartilaginous origin. It accounts for <0.5% of all bone tumors. The first metacarpal is a rare site of origin of this tumor. This tumor of young age is cartilaginous with fibrous and myxoid elements affecting the metaphyseal region of a long bone. A 35-year-old female presented with chief complaints of pain and swelling in her right thumb for 2 years. The range of movements was restricted and painful. The patient was unable to use the thumb for any daily activities. The radiograph showed an expansile bubbly lesion with sclerotic rims. The computed tomography scan showed a well-circumscribed heterogeneous hypodense lesion with cortical destruction. Wide resection of the lesion was done, and the defect was substituted with a fibular strut graft and bone grafting for pseudoarthrosis. Histopathology reports suggested tissue with mature cartilage and paucicellular myxochondroid matrix with multinucleate giant cells and spindle cells, suggesting chondromyxoid fibroma. Chondromyxoid fibroma of the first metacarpal is an exceptionally rare condition. One of the primary concerns when managing this particular location is the potential loss of opposition, which is crucial for hand functionality. Despite the inherent risk of recurrence, a wide resection combined with strut grafting is a highly promising approach that can lead to a favorable prognosis and the restoration of hand function. This method not only effectively addresses the tumor but also provides structural support to the metacarpal bone, improving the likelihood of a successful outcome. By preserving hand function and mitigating opposition loss, patients can regain essential dexterity and grip strength.