Structure of nodular thyroid pathology in population of the Orel Region: analysis of data revealed by cytological examination during a screening study

Full text: To analyze the structure of nodular thyroid pathology based on cytological examination data collected during a large-scale screening study of population of the Orel Region, as one of the regions of the Russian Federation (RF) contaminated with radionuclides after the Chernobyl accident. Fine needle aspiration biopsy (FNAB) specimens were collected from 433 residents of four Rayons of the Orel Region of the RF (Bolhovsky - 224 persons, Mtsensky - 81, Uritsky - 69, Kolpnyansky - 59). The sampled group included 68 males (15.7%) and 365 females (84.3%) aged 14 - 78 years (44 years old, mean). Slides were stained using Pappenheim's procedure. A total of 30268 individuals living in four Rayons of Orel Region have been subjected to ultrasound thyroid examination that identified 5277 (17.4%) persons with thyroid nodules. Among them, 4821 patients were further seen by an endocrinologist. Based on the specialist's opinion, FNAB was done in 433 cases. Cytological examination revealed that most of thyroid nodules resembled cellular and colloid goiter (209 persons, 48.3%) and nodular type of lymphocytic thyroiditis (25; 5.7%). Cells of cystic thyroid lesions were detected in 44 FNABs (10.2%). Non-informative samples were obtained in 72 cases (16.5%). Thyroid tumors were diagnosed in 58 individuals (13.4%). Follicular tumor (FT) was diagnosed in 22 persons (5.1%), suspicious for FT in 18 (4.2%), Hurtle cell tumor (HT) in 14 (3.2%) and suspicious for HT - 4 (0.9%). Prevalence of thyroid tumors was comparable in three examined districts: Bolhovsky Rayon - 33 persons (14.7%), Mtsensky - 11 (12.5%), Kolpnyansky - 9 (15.3%). In Uritsky Rayon the number of cases was lower, 5 persons (7.2%). Twenty-five patients (5.8%) were diagnosed for thyroid cancer (TC) or assigned as suspicious for TC. Papillary thyroid cancer (PTC) was diagnosed in 12 persons (2.8%), suspicious for PTC in 9 (2.1%), and thyroid carcinoma not otherwise specified in 4 cases (0.9%). TC was diagnosed more often in Kolpnyansky (9 persons, 15.3%) and Uritsky Rayons (10 persons, 14.5%) while in Mtsensky and Bolhovsky Rayons TC prevalence was lower (4 persons, 4.9%) and (2 persons, 0.9%), respectively. Cytological examination demonstrated that nodular goiter is a predominant lesion in the structure of nodular thyroid pathology. Benign and malignant thyroid tumors were detected less often. Prevalence of thyroid tumors apparently differs between the examined areas of one region. Further study is needed to explain the observed discrepancies