NEOPLASTIC AND NONNEOPLASTIC THYROID LESIONS IN SURGICAL MATERIAL - HISTORICAL REVIEW OF 5 DECADES IN SAO-PAULO, BRAZIL

Aims and background: The goal of the study was to report and discuss t he neoplastic and non-neoplastic diseases of the thyroid gland present in a historical series of surgical material examined during the perio d 1945 to 1989 at the Pathology Department of the Sao Paulo University Medical School. Methods: Records of 281,175 cases were reviewed to se lect those which affected the thyroid gland. The slides of these selec ted cases were analyzed and classified according to current terminolog y. Results: Non-neoplastic lesions comprised 86.68% of the cases (n = 7024), and most of them were nodular goiter (n = 6458). Neoplastic les ions were divided into two groups: primary and metastatic. Of 1072 pri mary neoplasms, 530 were benign;and 542 were malignant. Of the maligna nt neoplasms, papillary and follicular were the most frequent types (n = 201 and 187, respectively), followed by undifferentiated (n = 86), Hurthle (n = 46), medullary (n = 16) and others (n = 6). Of 8 metastat ic neoplasms, 4 were from and undetermined primary epidermoid carcinom a. Conclusions: We concluded that owing to the high incidence of neopl astic lesions (13.32%), half of which were malignant, examination of t he thyroid gland should be done with strict criteria in view of the th erapeutic and prognostic implications.