Nodular Goiter and Malignant Lesions of the Thyroid Gland*

THE lack of agreement in recent reports concerning the incidence of carcinoma in cases of nodular goiter and the current tendency to minimize the incidence of malignant change in multiple nodular goiter led us to review the association of cancer and nodular goiter in cases observed at the Mayo Clinic. All cases of malignant lesions of the thyroid gland seen at the clinic from 1907 to 1937, inclusive, have been reviewed previously and reported by one of us (Pemberton (1)). The present study, consequently, was limited to cases of malignant lesions of the thyroid gland seen during the decade from 1938 to 1947, inclusive. The findings, in general, with the exception of an unexplained change in the incidence of the different types of carcinoma, were in keeping with those in the earlier series. The findings also supported the belief long held by us and by others, that clinically unrecognizable carcinoma occurs sufficiently often in nodular goiter to warrant thyroidectomy in the great majority of such cases.