Endocrine Abstracts

Introduction: Co-occurrence of differentiated thyroid carcinoma (DTC) and chronic autoimmune thyroiditis (HT) is a debatable subject in many studies. It’s noted that patients with HT have less aggressive tumors and a better prognosis, possibly related to the immune response against tumoral cells.

Aim: To evaluate demographic, clinical, laboratorial, histopathological parameters in patients with HT and DTC, compared to the patients without HT, focusing on differences in tumor aggressivity.

Methods: This study is a case-control retrospective study, where 106 patients were evaluated, 68 patients with HT and DTC and a control group of 38 patients without HT. The data are analyzed using IBM-SPSS v.24.

Results: Patients with HT and DTC were mostly females (95.6%) and of the age group 41-50 years old, with a mean age of 47.34 years old. In most of the patients, biopsy description was that of papillary carcinoma (52.9%), with predomination of classic variant. The majority of primary tumors in patients with HT were 0-2 cm (69.7%), unilateral (76.3%) and unifocal (68.2%). 66.1% of patients with HT had no capsular invasion, significantly less than the patients without HT (P 0.016). Vascular and extrathyroidal, despite being less frequent, had no statistical significance. Only 11.7% of the patients with HT have lymph node metastasis and advanced age proved to be the only relevant risk factor for that (P 0.002). None of the patients with HT had distant metastasis, which compared to the group without HT was statistically significant (P 0.05). All patient were treated with radioactive iodine and the most frequently used dose was 100 mCi (48.8%). Unlike the group without HT, all patients with HT took only one dose of radioactive iodine (P 0.021).

Conclusions: Patients with HT have some features which are less aggressive compared to those without HT as: less capsular invasion, lack of distant metastasis and less frequently treated with radioactive iodine. Because of their risk of malignancy, patients with HT should be monitored periodically.

Keywords: HT, differentiated thyroid cancer, tumor aggressivity