No abstract

The postoperative outcome (including clinicopathologic features) in 19 patients with differentiated thyroid cancer of the isthmus was investigated to develop more appropriate surgical strategies for these lesions. The extent of thyroidectomy, including neck dissection, tumor size, nodal involvement, and other clinical features were evaluated. The incidence of intraglandular dissemination was about 16% in all patients. Analysis of regional node metastatic distribution revealed no definite metastatic pattern. In addition, there was no apparent correlation between tumor size and nodal involvement. Two of the six patients who underwent total thyroidectomy suffered permanent postoperative hypoparathyroidism. It is thus recommended that isthmusectomy, including an adequate edge of surrounding normal thyroid tissues of each lobe and modified or limited neck dissection when cervical nodes are palpably enlarged, is sufficient as an appropriate primary surgical procedure for differentiated carcinoma of the thyroid isthmus.

Several reports have been published on the anti-TSH receptor antibody in putative autoimmune thyroid disorders using a radioreceptor assay. We have carried out correlative studies between the ability of serum immunoglobulins to displace radiolabeled TSH from the thyroid plasma membrane receptor [TSH-displacing activity (TDA)] and that of actual stimulation of the human thyroid gland [human thyroid-stimulating activity (hTSA)] in Graves' and other thyroid diseases and in control subjects. TDA was assayed by the use of a radioligand technique, while the activation of adenylate cyclase in human thyroid slices was measured as an index of hTSA. The same immunoglobulins were employed for both assays. In this series, positive TDA and hTSA values were found in 70.4% and 81.5% of the samples in active untreated Graves' disease, respectively. Samples from normal persons and from several patients with toxic nodular goiter gave generally negative results in both assays; in a small proportion of patients with either subacute thyroiditis or Hashimoto's thyroiditis, the TDA was positive but hTSA proved to be negative. In Graves' disease (including those patients on propylthiouracil) in remission and treated with 131I, the correlation between TDA and hTSA was not significant (r = 0.309; P greater than 0.1); even when the procedures were compared in the untreated group alone, there was no significant correlation between the two activities (r = 0.309, P greater than 0.1). These studies indicate that 1) significant TDA and hTSA are observed in Graves' disease; nevertheless, the correlation between them is not significant; 2) the hTSA assay appears to be more sensitive and specific than the TDA assay; and 3) TDA may not be synonymous with thyroid stimulation.

Ninety-one small differentiated thyroid carcinomas less than 10 mm in size treated during the last 33 years were subjected to clinical study. In 44 of the 91 cases, tumor was found incidentally at surgery, while in the remaining 47 a thyroid mass was palpable before operation. A preoperative diagnosis of carcinoma could not be made in nodules less than 5 mm in size. Ultrasonographic examination is now extending the limits of exact diagnosis. Metastasis was found in 16 of 33 patients who had lymph nodes dissected. Metastatic lymph nodes were distributed in the same sites as those with thyroid carcinomas larger than 10 mm. Pathologic examination was carried out in 108 small carcinomas including cases from an affiliated hospital. Histologically, all of them were papillary or follicular carcinomas. The growth pattern of the tumors was divided into 5 groups: 23 were nonencapsulated sclerosing type, 29 encapsulated type without capsule invasion, 48 encapsulated type with capsule invasion, 4 the infiltrative type, and 4 the round type. Lymph node metastasis and intraglandular dissemination were found most frequently in the infiltrative type, followed by the encapsulated type with invasion. The results suggest the necessity of lymph node dissection and lobectomy for patients with these histological types of small carcinomas who had only local removal of the tumor.