he insidious onset of thyroid hypofunction and retardation of growth in the Marshallese children was probably associated with the slow loss of functioning thyroid cells through lack of replacement due to radiation impairment of cellular replication. One can speculate that less injured cells in the thyroid probably responded to the increased TSH simulation and the picture of concomitant atrophy and hyperplasia resulted in gross nodule formation. In the 2 cases with complete thyroid atrophy, however, there must have been sufficient radiation damage to prevent appreciable responses to TSH stimulation. No Jvoubt there is increased risk of cancer of the thyroid in the Marshallese children and it is perhaps chance that no such malignancies have yet been discovered. The literature is replete with many retrospective as well as prospective studies which show the late development of cancer of the thyroid in children that had been treated with cervical irradiation during infancy and early childhood.[11-13] However, there is scant evidence as yet for the development of cancer of the, thyroid following radioiodine treatment. Increased prevalence of cancer of the thyroid has been reported in adults exposed tc the atomic bomb in Hiroshima [14] and other types of radiation.[15] It is of course not possible to prove the causal relation- ship of irradiation in the case of cancer of the thyroid in the exposed women reported here, but in view of low incidence of such lesions in the Marshallese, this possibility must be seriously considered. It is not known whether treatment with thyroid hormone will reduce the risk of cancer of the thyroid in the human being. However, sch suppression has been reported to prevent the development of thyroid nodules in rats.(16] It is hoped that the hormone treatment being given the Marshallese may suppress such neoplasia from radiation. SOC 1bO2