Current issues relating to diagnostics and treatment of papillary thyroid cancer with coexistent autoimmune thyroiditis

Abstract

Recent studies have shown that papillary thyroid cancer (PTC) associated with autoimmune thyroiditis (AIT) has a higher percentage of malignant nodes. However, it has not been studied how AIT affects the development and course of PTC.The aim was to determine the incidence of autoimmune thyroiditis in papillary thyroid cancer and study the frequency of its metastasis.Materials and methods. A retrospective analysis of 63 case histories of patients diagnosed with PTC who received treatment in the Surgery Department of “VIZUS” LLC from January 2018 to December 2019 was performed. The mean age of the patients was 53.1 ± 10.4 years. There were 56 (88.9 %) women and 7 (11.1 %) men among the patients. All the patients underwent surgical treatment. An inclusion criterion for the main group was pathohistologically confirmed PTC and AIT – 33 patients (52.4 %). The comparison group included patients with PTC without AIT – 30 (47.6 %).Results. Hypothyroidism was detected in 5 (15.2 %) persons of the main group, and the other patients were diagnosed with euthyroidism – 28 (84.8 %). All the comparison group patients - 30 (100 %) were in a state of euthyroidism. Elevation of antibodies to thyroperoxidase (AT-TPO) was found in 14 (42.4 %) persons in the main group, while no increase in this indicator was found among the comparison group patients. The specific to AIT changes in the ultrasonographic characteristics of the thyroid parenchyma were detected in 13 patients (39.4 %) of the main group and in 9 (30.0 %) patients of the comparison group, P = 0.3714. Following the cytological examination results of thyroid nodule aspirates, follicular neoplasia was detected in 6 (18.2 %) patients of the main group and in 2 (6.7 %) of the comparison group, P = 0.0473. The pathohistological examination revealed a combination of PTC with AIT in 33 (52.4 %) patients. Cancer metastasis to the regional lymph nodes was observed in 14 (42.4 %) patients with AIT and 10 (33.3 %) patients of the comparison group, P < 0.0356.Conclusions. The results of ultrasound, fine-needle aspiration biopsy and measurement of serum thyroid hormone levels are not sufficiently informative to diagnose AIT. The specific to AIT changes in the thyroid parenchyma impede the diagnosis of malignancies. The metastasis frequency in PTC with coexistent AIT is higher than without it.