Faculty Bibliography

Computerized axial tomography (CAT) was used to study 39 patients with known thyroid disease and 14 patients with primary hyperparathyroidism. In all, CAT was performed only when information that was required for diagnosis or therapy was not available from other less expensive techniques. The greatest value was found in the evaluation of cryptic symptoms or structures in the neck after surgery for thyroid cancer, the assessment of the extent of thyroid cancer, the localization of aberrant thyroid tissue, the etiology of unexplained recurrent laryngeal nerve paralysis and the identification and delineation of mediastinal goiter. In six of 14 patients undergoing neck exploration for primary hyperparathyroidism CAT correctly localized the site of the enlarged parathyroid glands including one mediastinal parathyroid adenoma and one patient with two parathyroid adenomas

Seven patients with carcinoma in a thyroglossal duct cyst have received treatment over a 15 year period. Findings in all of these patients reflect the likelihood of carcinoma arising within thyroglossal duct tissue. In each patient there was sufficient histologic evidence of the presence of a thyroglossal duct cyst and carcinoma arising within an intimate admixture of normal thyroid tissue in the cyst wall. In the absence of a history of irradiation and with separation of the carcinoma from the pyramidal lobe of the thyroid, excision of the thyroglossal cyst alone by traditional means seems appropriate. Our experience as well as a review of reported cases to date indicate that distant metastases are extremely rare and the prognosis excellent

The euthyroid autonomous nodule of the thyroid may escape diagnosis if only the usual criterion of less than 50% suppression of radioactive iodine uptake, (RAIU) after administration of liothyronine sodium is employed. This was the case in four patients who had thyrotoxic response to suppressive therapy, which had been given as a result of the improper conclusion that a nodule was hyperplastic, after the RAIU had fallen. We studied 95 patients with a solitary functioning nodule and found ten euthyroid persons (11 tests) in whom scintiscans showed persistent function in the nodule in spite of suppression of the RAIU by more than 50%. A thyrotropin-releasing hormone test demonstrated lack of thyroid-stimulating hormone responsiveness after administration of liothyronine, proving adequacy of the suppressive dose. Diagnosis of an autonomous nodule should not be excluded unless a scintiscan reveals that its function, in distinction to the rest of the gland, is curtailed by adequate suppression.