NEOPLASTIC AND NONNEOPLASTIC THYROID LESIONS IN AUTOPSY MATERIAL - HISTORICAL REVIEW OF 6 DECADES IN SAO-PAULO, BRAZIL

Aims and background: The aim of the study was to report and discuss a historical series of neoplastic and non-neoplastic lesions of the thyr oid gland obtained at autopsy that were examined between 1931 and 1989 at the Pathology Department of the Medical school of the University o f Sao Paulo. Methods: Records of 145,043 cases were reviewed to select those affecting the thyroid gland. The slides of these selected cases were analyzed and classified according to the current terminology Res ults: Non-neoplastic lesions comprised 91.62% of the cases (n=4647), a nd most of them were adenomatous goiter (n=3014). Neoplastic lesions w ere divided into two groups: primary and metastatic. Of the 282 primar y tumors, 135 were benign and 147 were malignant. Among the malignant neoplasms, the most frequent types were follicular, papillary and undi fferentiated (n=39, 36 and 29, respectively). The most frequent tumor types among the metastatic neoplasms were lymphoproliferative processe s and carcinomas (n=67 and 34, respectively). Conclusions: We conclude that, because of the high frequency of neoplastic lesions (8.38%), 68 .24% of which were malignant, detailed examination of the thyroid by p athological methods should be carefully and systematically performed f or the accurate detection of thyroid lesions, especially carcinomas.