Abstract
The definition and the entity of adenomatous goiter are still obscure in Japan, in spite of the detailed description by our coworker, Dr. Sawada. To clarify the differences between adenomatous goiter and adenoma, radiological and histological methods were used. One hundred and thirty four cases of adenomatous goiter and 1083 cases of adenoma were subjected to this study.
In adenomatous goiter many nodules are scattered through the whole gland or located in a part of the gland showing conglomerate appearance. Histologically definite capsules surrounding nodules are not observed. Various steps of the development of follicle, from immature to large mature, are seen. These findings suggest the hyperplastic character of this disease.
The frequency of adenomatous goiter among simple nodular goiter is 11.0%. There was no difference in this frequency before and after 1964.
The scintigram of adenomatous goiter frequently shows irregular cold nodule which is distinguishable from typical cold nodule of adenoma.
The differential diagnosis between adenomatous goiter and thyroid cancer is sometimes difficult. In our series, 14.9% of adenomatous goiter was misdiagnosed as cancer preoperatively. However, comparing the frequencies of the misdiagnosis before and after 1964, it decreased after 1964.
In gross findings adenomatous goiter sometimes shows conglomerate appearance, however has little tendency to cystic degeneration. Adenomatous goiter is classified into scattered type and circumscribed type, and unilateral type and bilateral type. In age distribution of each, the unilateral type is observed more frequently in younger generation than bilateral type.
There are still some unknown problems concerning the histological difference between adenomatous goiter and multiple adenomas.
