-17The irradiated Marshallese thyroids often have many minute soljid cellular or mixed papillary and follicular lesions in addition to the much larger lesion which had drawn primary attention on physical examination. Many of the occupying an area no larger than a dozen normal follicles just as diny lesions are is seen in the radiated rat thyroids. An exposed Marshallese waman on wham we did a total thyroidectamy in 1969 for Carcinoma has developed a pituitary tmor, as evidenced by erosionlof the sella tursica. This may be the first human example of the Furth mice in were destroyed and a pituitary tumor rich in TSH subsequently deve clincal case, the woman had presumably been taking the T, supple In this as supplied. The final important observation among the Marshallese has been the elopment of lesions in 2 young men who at the time of exposure were in utero. determined, the fetuses were sufficiently developed so that the taken up radioiodine. id should have The thyroids in these cases showed multiple recently operated one of the mothers for what proved to be miltipla "atypical" adenoma The long delay in the development of neoplasms following ‘i in the Marshallese as well as in the animals. Our experience has do not develop lesions readily unless they are irradiated when ve 2/3 of the life span has lapsed. 9 years. young and 1/2 to The first Marshallese lesions didjnot develop for Many of the first lesions found came from the atoll with [he greatest fall- out (Rongelap). It was quite some years later that lesions began appearing in peonle who were on the next nearest atoll (Alingnae) where the dose had bein somewhat less. While lesions were appearing on the nearer atolls, the low dose recRived on an atoll much further away (Uterik) seemed to have produced no lesions. However, in the most Tecent years, 8 individuals have been cperated from this most remot# of the carinomas found have come fram this atoll. These observati atoll. Four emphasize even more the risk of the low dose range and the long latent period to pyoduce neoplasms.