A patient with an instraphalangeal keratin cyst that became troublesome four and one-half years after removal of an enchondroma at the same site has been described. In addition, keratin cysts in bone reported between August 1923 and April 1967 have been analyzed according to the age and sex of the patient, location of the lesion, history of trauma, roentgen findings, treatment, and histopathological diagnosis. Regrettably, amputation was performed for twenty-seven of the eighty-four cysts recorded. Recommended treatment is excision of the cyst, curettage, and packing with bone chips.