Fine Needle Aspiration Cytology and Thyroglobulin Antibodies in Preoperative Diagnosis of Thyroid Malignancy

Introduction: Most important in the evaluation of thyroid thyroid disease is to differentiate a disease that is treated medically from a disease that requires surgical treatment. In preoperative differentiation of a malignant from a benign lesion are used different diagnostic methods (US, scintigraphy, FNAC, MRI).

Aim: The aim of the study was to determine the diagnostic value of fine needle aspiration cytology (FNAC) and serum thyroglobulin antibodies (TgAb) values in individual cytological categories.

Methods: The prospective study included 100 patients with scintigraphic cold thyroid nodules divided into two groups. The first group consisted of 50 patients with histopathological verified benign nodules and the second group of 50 patients with histopathological verified benign nodules. Demographic datas, FNAC findings, TgAb levels and final histopathological findings were recorded. FNAC with ultrasound (US) guidance was performed by the so-called Free hand technique. TgAtb values were estimated by the radio-immunity assay (RIA) method.

Results: In patients with histopathological findings of a benign nodule, 20 patients had a cytological finding of a colloidal nodule, 18 patients had a cellular nodule, 12 had a finding of follicular neoplasm. In patients with a histopathological finding of the malignant nodule, 9 patients had a cytological finding of a colloidal nodule, 8 had a cellular nodule, 21 follicular neoplasm and 12 patients had cancer. FNAC had a sensitivity of 66%, specificity of 76%, a positive predictive value of 73%, a negative predictive value of 69%. The highest preoperative serum TgAb values were in patients with cytologic findings of cancer, and the lowest in the cellular nodule.

Conclusion: The finding of FNAC together with serum TgAb values contributes to better diagnosis and selection of patients requiring surgery.