43 Table 25 Thyroid Lesions in Marshallese. December 1974 Group Rongelap exposed 1173 rads) Age at exposure Est. thyroid dose, rads Subjects® with thyroid lesions No. subjects with surgery “ Subjects® with malignant lesions <10 10-18¢ 810-1150 335-810 89.5¢17 19) 16.6/2 12) 15 1 3.3(1 19) 3 6.112 33) >18 All Ailingnae exposed (69 rads) <10 10-18 >18 All in utero exposed Utink exposed (14 rads) Rongelap unexposed <10 10-18 >18 All 335 536¢ 275-450 190 135 217e 175 +> 69 +> 60-958 27-60 27 50° <10 10-18 Likiep unexposed 91/3 3314 34.4(22 64) 33.312 6) 19 If 0.0(071) 0 33.3 (6, 18) 4 36.3 (4/11) 33 3(1°3) 0.0 (0/1) 0.0 (0°58) | 4.8(1/21) 6.4 (3/78) 3.8 (6, 157) 1.6 (1/61) 7.7 (1/13) 4.7(3 64) 3 1 0 0 1 3 + 4.8 (1, 21) 0.6(1 157) 0 1 > 18 All 5.8 (7/120) 4.6 (9/194) 2 3 <10 0.0 (0/31) 0 >10 All 4.7 (5,106) 3.6 (3/137) 0 0 4Dose from 1311, 132], 133], and 135] plus gamma; mean dose extrapolated from calculations?for adults and 3-vear-olds ‘see Section II). > Based on numberof people exposed, excluding those in utero (numberof cases/total numberin group). ° The thyroid is considered to be fully developed by about age 18. 4QOne additional case of adenoma, found at autopsy, not included here. * Weighted mean dose. ‘ Pathologists differed as to whetherthis lesion was malignant; it was scored as benign. * The more energetic, shorter-lived isotopes of iodine contributedless to the total thyroid dose in the Utirik people because the fallout occurred later there. It might be surmised also that the biological effectiveness of the thyroid dose per rad would be less in the Utirik group. roid surgery has been carried out on 24 ofthe exposed Rongelap people with removalof varying amounts of thyroid tissue depending on the extent of the lesions (20 were subtotal and 4 total thyroidectomies with parathyroidectomyinadvertently in one of the latter who was thought to have cancer at the time of surgery). Of these cases, 3 were found to have carcinoma ofthe thyroid and 21 to have benignlesions of the thyroid. The first case of carcinoma ofthe thyroid oc- curred in a 40-vear-old woman (29 at the time of exposure} in the heavily exposed group. Theinterval between exposure and diagnosis was 11 vears.70.23 The second and third cases in this group occurred 15 years after exposure, in a 36-year-old woman (age 21 at exposure) and in a 22-year-old woman(age6 at exposure). A fourth case of cancer was found, 14 years after exposure, in a 36-year-old Utirik woman whohad received considerably less exposure.23 Three of 196 unexposed Rongelap people have had surgery with removal of benign adenomas. All three were women. Hospital summaries of cases admitted at BNL are presented in Appendix 10. 1. Gross Appearance Since the discovery of the first thyroid lesion 9 years after radiation exposure, clinicians particularly interested in the thyroid have participated in the annual examinations. As a result, anyslight irregularities discovered by palpation drew special attention. This high degree of scrutiny and suspicion led to the detection and removalof nodules