SURGICAL TREATMENT OF CARCINOMA OF THE THYROID GLAND

ATTEMPTS to devise a standardized surgical procedure for managing JT\. carcinoma of the thyroid gland have not been signally successful, chiefly because of the marked differences in biologic behavior of the different types of carcinoma. Thus, a procedure that is rational for the management of papillary lesions is irrational for the treatment of malignant adenomas and diffuse adenocarcinomas. Removal of thyroid, contiguous tissues and zones of venous and lymphatic spread is an impossibility because of neighboring vital structures; and the necessity of radical operation in the majority of cases has been challenged. Survival and recurrence rates have been disappointing in the evaluation of the procedures which have been proposed, partly because of the slow natural progress of lower grades of malignancy and partly because of extremely rapid progress of more malignant lesions. In addition, because of differences in fundamental criteria of malignancy adopted by different pathologists, results following treatment at different institutions may not be comparable. At the Mayo Clinic, the extent of the surgical procedure is determined by the type of malignancy and its local spread, and no effort is made to manage all such growths in the same fashion. Radical operations are rarely carried out, except in the case of the papillary form, and even lesions of this type are usually treated by limited resections. This approach to the problem implies a knowledge of the type of malignancy, which can be secured only by biopsy (1); and information as to its local extent, which requires exposure and mobilization of the thyroid, at least in cases in which there is a reasonable chance of cure. The treatment of the primary lesion and that of the surrounding tissues will be discussed separately. This departure from the usual method of discussing treatment according to type of ca'rcinoma was chosen in order to bring the discussion into line with actual practice, since the thyroid gland is managed first, and regional tissues are considered only after the primary lesion has been dealt with.