THE results obtained from the use of radium in some cases of hemangiomas are all that may be desired. Instances have been seen in which large tumor masses have entirely disappeared without any sign of scarring, and the overlying skin was absolutely perfect. Many cases come under observation in which some surgical procedure has been employed, followed by recurrence of the mass and large scars, which make them more difficult to treat. Frequently, the blood vessels have enlarged beyond the previously involved area, giving a crater-like shape to the tumor, while in others, especially those cases in which carbon dioxide snow has been employed, large ulcers are seen. It would seem logical, therefore, that some mild irradiation should first be used and, if it fails, then resort to surgery. The method for the eradication of these troubles depends largely upon the following factors: (1) condition of the nevus when seen by the physician; (2) the previous history; (3) the histologic formation of the mass. For convenience in treatment, a purely arbitrary division has been adopted in this review of 506 cases of nevi, as follows: (1) hemangiomas, with subdivisions of different grades into capillary and cavernous, which comprised the largest, and totaled 422 cases; (2) lymphangiomas, which numbered 14 cases; (3) fibroangiomas, including the various forms of moles, which amounted to 70 cases. The difference between the rather large first group of hemangiomas and the small third group, including moles, is explained by the fact that, as a rule, when moles first appear upon the body they are small and are seldom brought to the attention of a physician until they become troublesome or large enough to cause disfigurement. If all cases of moles were recorded, the proportion in this review would no doubt be entirely different. The type of nevus most susceptible to irradiation is the cavernous hemangioma. Its history is quite distinct and differs from the others in that at birth, or shortly afterwards, a small spot is noticed which enlarges rapidly (within a few days, weeks, or sometimes a few months), then becomes stationary or may still continue to enlarge slowly. The history of the capillary type is not so distinct and there is some element of doubt as to its formation. Although many individuals will contend that nothing was seen at birth, a few days later the discoloration will be noted but, as time progresses, very little difference in its size and character will develop. The fact that these marks are flat and of no distinct tumor formation, naturally makes detection at birth rather difficult, due to the incidental discoloration of the child's skin. Moles are usually observed at birth, and show little change as time advances, and to some extent this is true of lymphangiomas. All three of the above-mentioned classes may remain stationary for years and then, for some unknown cause, enlarge rapidly.