Malignant tumors in children occur with sufficient frequency so that the diagnosis must always be kept in mind in dealing with sick youngsters. This entails some conditioning of the physician's thinking so that he is always alert to the possibility of malignancy in any differential diagnosis. Cases cannot be discovered early or proper treatment started immediately if the physician is not aware of the possibility of this diagnosis.
A review of the literature furnishes considerable evidence of the occurrence of these tumors.1-25 Yet, two distortions can occur in interpreting most studies in regard to the frequency of such conditions: (1) Few institutions are observing a representative cross-section of all types of tumors in children. The type of case admitted may be dependent upon the reputation of the institution's staff in attracting patients with that particular disease—such as the large specialized cancer hospitals—and such cases will not reflect the true