Neoplastic and Non-Neoplastic Thyroid Lesions in Surgical Material: Historical Review of Five Decades in São Paulo, Brazil

Abstract

Aims and background The goal of the study was to report and discuss the neoplastic and non-neoplastic diseases of the thyroid gland present in a historical series of surgical material examined during the period 1945 to 1989 at the Pathology Department of the Sao Paulo University Medical School. Methods Records of 281,175 cases were reviewed to select those which affected the thyroid gland. The slides of these selected cases were analyzed and classified according to current terminology. Results Non-neoplastic lesions comprised 86.68% of the cases (n = 7024), and most of them were nodular goiter (n = 6458). Neoplastic lesions were divided into two groups: primary and metastatic. Of 1072 primary neoplasms, 530 were benign and 542 were malignant. Of the malignant neoplasms, papillary and follicular were the most frequent types (n = 201 and 187, respectively), followed by undifferentiated (n = 86), Hürthle (n = 46), medullary (n = 16) and others (n = 6). Of 8 metastatic neoplasms, 4 were from and undetermined primary epidermoid carcinoma. Conclusions We concluded that owing to the high incidence of neoplastic lesions (13.32%), half of which were malignant, examination of the thyroid gland should be done with strict criteria in view of the therapeutic and prognostic implications.