Rectal carcinoma metastasizing to a toe.

We report on a 63-year-old patient with rectal carcinoma that metastasized to a toe. Although bone metastases from malignant tumors are common, metastatic lesions of the small bones of extremities are very rare. We have found in the literature only 29 cases of carcinoma which have metastasized to the small bones of the feet. Twenty of these cases are verified histologically. The differential diagnosis includes osteomyelitis, gout, and Reiter's disease. The roentgenographic features and the possible pathogenetic mechanisms of peripheral metastases are discussed.