Structural and morphologic characteristics of nodular goiter in chronic iodine deficiency status

Abstract

OBJECTIVES . Diffuse and nodular goiter are the most common thyroid gland (thyroid) diseases in children and adults living in iodine-deficient regions. Thyroid hormone potentiates progressive hypertrophy and hyperplasia of thyrocytes, with uneven proliferation of thyroid cells leading to nodule formation. Iodine deficiency, which promotes replication of thyroid follicular cells, also increases the incidence of TSH Receptor mutations, leading to receptor activation and autonomous functioning of follicles. AIM . To evaluate and describe ultrasound and cytologic thyroid nodes in the regions in Russia with proven iodine deficiency. MATERIALS AND METHODS . The study was conducted in regions with proven iodine deficiency in the Central and North Caucasian Federal Districts. Population of conditionally healthy adult volunteers (mean age — 47.5 years) was recruited as part of visiting events to screen for the occurrence of thyroid nodes. RESULTS . The results obtained indicate a high prevalence of multinodular colloid goiter in adult patients living in conditions of chronic iodine deficiency. In the Chechen Republic, the prevalence of nodular thyroid pathology was found in 64.5% (205/318) of cases, and in the Tula region — in 40.6% (116/286). In the studied sample the results of cytologic examination confirmed the presence of colloid thyroid masses in 97% (60/62) — Bethesda category II; in 3% (2/62) of patients nodular masses had Bethesda IV. Diffuse goiter prevalence in the examined population was 20.8%. CONCLUSIONS . A study indicates a high prevalence of iodine-deficient thyroid disease — multinodular colloid goiter in regions with proven chronic iodine deficiency. The wide prevalence of goiter with colloid and cystic components is confirmed by the cytologic examination with different ultrasound characteristics according to the EU-TIRADS classification. The obtained data correspond to the official statistics demonstrating high prevalence of nontoxic goiter in adults in the examined regions, which is an important argument confirming the need for systemic iodine prophylaxis.