World J. Surg. Vol. 16, No. 1, Jan./Feb. 1992 136 revealed only 4 thyroid operations. One of the 4 was said to have been a carcinoma (Dr Julian, the surgeon at Majuro Hospital, personal communication). As emphasized in this report, there is sometimes difficulty drawing a distinction between benign and malignant thyroid neoplasms. The effect of radiation on the thyroid cells adds to the difficulty because of bizarre nuclear forms which may develop [13, 16]. Such nuclei may contain excessive amounts of chromatin not unlike malignant cells [14-16] (Figs. 4, 7 and 8). Furthermore, the radiation may damage the function of the gland, causing a decrease in production of thyroid hormone and a superimposed compensatory stimulus for cell division among the surviving cells [14]. This may result in cellular hyperplasia with the formation of papillary structures. It is therefore not surprising in the case of the Marshallese that pathologists might disagree about the diagnosis and the potential for some lesions to metastasize. Many of the papillary and mixed papillary and follicular thyroid lesions grow very slowly. Once removedit is impossible to say what that lesion might have done. The Marshallese accident has given an unique opportunity to see these thyroid lesions develop after a single simultaneous event in multiple individuals. Some lesions were so small that they had not yet grownto the extent that there was overt invasion of the capsule or the wall of a blood vessel; yet, the cellular forms sometimes provided a basis for suspicion that some of these small lesions had not fully declared their pathophysiologic potential and spread to lymph nodes. As this experience has evolved, the occasional uncertainty of the diagnosis at surgery prompted this surgeon to removeall lymph nodes in the immediate drainage area of a lobe which contained a lesion in question. It was a fortuitous finding that in these cases there were 5 instances of spread to lymph nodes while the primary was only I cm orless Fig. 9. This female was exposed on Rongelap at age 7. Bilateral subtotal thyroidectomy, removing all gross nodules, was done at age 22, The gland displayed many discrete lesions of various size and patterns, the largest being 1.0 cm. A palpable mass recurred 10 years later. Total thyroidectomy revealed manysimilar lesions, the largest being 1.5 cm. No malignant change had occurred in the interval. A variety of small papillary, solid cellular, and follicular patterns scattered throughout the gland at the first operation (x25). outside the fallout area, there were 5 people in this group who developed masses over the years. One was carcinoma. It seemed clear that neoplasms sometimes arise spontane- ously in the Micronesians, as they do in other parts of the world. A review of the surgery logs at the Majuro Hospital (which receives patients from the entire Trust Territory) dating from the early 1960s to the late 1970s, revealed an occasional thyroidectomy and several carcinomasof the thyroid (personal review by BMD). Most of these surgical cases came from the Caroline and Marianna Islands, far west of the fallout area. Noneof these cases were being cared for by the Marshall Island Brookhaven Medical Team. Recently Hamilton and coworkers [29] reported finding thyroid masses in’ people living in more remote parts of the Marshall Islands. As of March 1989, a review of thyroid operations logged at the Majuro Hospital for the i years preceding and following the Hamilton report gdb 2 eed in diameter, in 3 cases to only a single lymph node. Many writers consider such small lesions in the thyroid to be innoc- uous [17-19, 26, 30]. In this study the circumstances led to the discovery of carcinomas that seemedto be in an incipient stage of development. If these small lesions had not been discovered by the palpation of experts or found incidentally at surgery (undertaken for what proved to be a benign lesion), it is reasonable to speculate that the pathological process would probably have continued until the primary lesion had become obviously palpable and many nodes by then would have become positive. The latter scenario is the customary finding encountered in a general surgical experience, where a frank carcinomais palpably obvious with many positive nodes discovered; just as occurred here in 3 cases where the primary lesion was large (easily palpable) and many nodes were involved. Three or more decades ago many observers [24, 26, 31-35] reported on the multicentric nature of papillary carcinoma of the thyroid. At that time, the importance of the relationship of thyroid carcinomato the previoususeof radiation treatment for thymic hypertrophy and inflammatory disease of the neck had not been appreciated. Multicentricity was reported to befre- quent when tiny sites were looked for. The occurrence of positive nodes was reported to be very high (31, 33, 35; 36]. These were usually more advanced cases in which a clinically evident mass had drawn attention; however, it was not always