CHRONIC THYROIDITIS: A CLINICAL AND PATHOLOGIC STUDY OF 354 PATIENTS*†

Abstract

CHRONIC thyroiditis, as evidenced by lymphoid infiltration, fibrosis and epithelial alteration of the thyroid gland, is a poorly defined thyroid disorder. Since the classic descriptions of Riedel (1, 2, 3) and Hashimoto (4), numerous controversial reports on chronic thyroiditis have appeared in the literature (5–24). These have not shown uniform opinions on the etiology, pathogenesis, classification and terminology or treatment of this group of thyroid diseases. The present report is concerned primarily with a pathologic appraisal of 195 thyroid glands which displayed three types of diffuse thyroiditis, 1) lymphadenoid goiter (“Hashimoto” thyroiditis, struma lymphomatosa), 2) granulomatous or giant-cell thyroiditis, and 3) “Riedel” thyroiditis (Table 1). Included in this study were an additional 159 glands in which the chronic thyroiditis of the “Hashimoto” type was either focal or was associated with other diseases of the thyroid gland (Table 2). The purposes of this paper are 1) to describe and illustrate the pathologic lesions of each of the three types of chronic thyroiditis, 2) to make clinical correlations which may aid in the clinical diagnosis, 3) to delineate and emphasize the wide scope of the pathologic manifestations of lymphadenoid goiter, 4) to clarify the interrelationships of lymphadenoid goiter with hyperplastic, involutionary and neoplastic processes in the thyroid gland, and 5) to discuss various views regarding the etiology and pathogenesis of each type of chronic thyroiditis.