機能性甲状腺癌の一例

Abstract

A 62-year-old woman with large tumor of the thyroid manifesting thyrotoxicosis is presented. Thyroid function tests showed a slight hyperthyroidism. Radiolabelled iodine accumulated in some parts of the tumor and the others were cold. Triiodothyronin (l-T＿3) administration showed non-suppression of the hot pattern. Moreover the blood thyroxin level was not lowered following the suppression of thyrotropin (TSH) induced by l-T＿3 administration. A total tumorectomy was performed and the pathological examination showed various degrees of follicular carcinoma. Histological findings were compared to the radiolabelled iodine uptake by mapping of thyroid scintigram. The most highly accumulated area of radiolabelled iodine consisted of smaller follicles with coloid. However, the unaccumulated areas consisited of cancer cells simulated in fetal thyroid or solid and trabecular patterns. This clinical evidence indicates that thyrotoxicosis in this case is caused by the excessive secretion of thyroid hormones from which were produced the cancer cells of highly accumulated area of radiolabelled iodine.