[Functional aspect of thyroid tumors].

Total of 1663 consecutive operative cases with thyroid tumors were analysed as to the hormonal function. These tumors consisted of 195 adenomas, 140 solitary adenomatous nodules, 121 multiple adenomatous goiters, 31 cysts, and 176 carcinomas. Among the cases with solitary nodules, 16 were classified as functioning. Cases which showed elevated serum T--4 and T--3 levels were those with functioning nodules. Among the cases with adenomatous goiter, elevated T--4 level was observed in 10 cases and elevated T--3 level in 7. delta TSH after TRH injection revealed minimum in many cases with adenomatous goiter. Microscopically no difference was observed between functioning and non-functioning nodules. However, findings of electron microscopy and histochemical observations (acid and alkaline phosphatase) revealed elevated activities in functioning nodules. Thyrotoxicosis is not severe in thyrotoxic adenomatous goiter (so-called adenomatous goiter with hyperthyroidism) and no specific findings were seen in patient's age and size of goiter. High proliferative index, derived from DNA histogram, was observed in cases with adenomatous goiter.