Presentation of malignancy by metastasis to the carpal navicular bone.

Although peripheral metastases of many malignancies to bone are common, metastases to the hand and carpus are rare. This is the first report of a silent primary malignancy of the lung presenting as a metastasis to the carpal navicular bone. Only eight instances of carpal bone metastases secondary to all tumor sources were revealed in a search of the literature. The presentation of metastatic disease in the hand in an occult malignancy may be deceptive, often mimicking pulp space infection, osteomyelitis, septic arthritis, gout, acute rheumatoid monoarticular arthritis, tenosynovitis, or sympathetic dystrophy. These lesions often present as radiolucent lesions; histologic findings are consistent with the tumor of origin. Treatment is palliative and consists of resection or amputation. Radiotherapy should be avoided in the hand due to secondary fibrosis and scarring.