Introduction: A crucial issue in the management of thyroid nodules is an accurate estimation of their malignancy risk. The key tool for risk stratification is fine-needle aspiration biopsy. Unfortunately, approximately 20% of biopsy results are indeterminate. The malignancy risk assigned to these categories does not allow unequivocal further management.
Objectives: We aimed to assess the malignancy risk in indeterminate thyroid nodules in the Polish population, and to analyze the effectiveness of clinical decisions after an indeterminate cytological diagnosis in Polish clinical practice.
Patients and methods: This retrospective analysis included 222 indeterminate thyroid nodules in 222 patients. The ultrasound features were assessed based on scans preceding a thyroid biopsy. Cytology results were classified according to the Bethesda system. The nature of the thyroid nodule was determined on the basis of histopathological analysis or follow-up.
Results: The analyzed cohort comprised 82 lesions in Bethesda category III, 75 in Bethesda category IV, and 65 in Bethesda category V. The malignancy risk, estimated on the basis of histological verification and surveillance was 6.7% for Bethesda III, 11.3% for Bethesda IV, and 70.3% for Bethesda category V. An ultrasound pattern was not sufficient enough to refine the malignancy risk after obtaining an indeterminate cytopathology result. In surgically treated nodules, postoperative hypoparathyroidism was significantly more frequent following more extensive surgical procedures.
Conclusions: The majority of Polish patients with thyroid nodules assigned to Bethesda III and IV cytological categories are overtreated based on the use of diagnostic tools currently available in Poland.