Thyroid ultrasonographic charasteristics and Bethesda results after FNAB

Thyroid nodular disease (TND) is a frequent clinical problem and the major concern is the probability of malignancy in a solitary nodule or in one or more nodules of a multinodular goiter. For this purpose, neck ultrasound and fine needle aspiration biopsy (FNAB) under ultrasound guidance have been established as the initial investigation of choice.

A total of 1113 patients (210 male/903 female) underwent FNABs for the same number of thyroid nodules. Correlated were the demographic profile (age and gender) and sonographic features of these nodules with the FNAB outcome. The Bethesda system (B) for reporting thyroid cytopathology was used.

Out of total 1113 cases, 255 (22.9%) were characterised as nondiagnostic (B1), 780 (70.1%) were diagnosed as benign (B2), 35 (3.1%) were diagnosed as B3 (atypia/ follicular lesion of undetermined significance), 10 (0.9%) were diagnosed as B4 (follicular neoplasm or suspicious for follicular neoplasm), while 13 (1.2%) cases were categorized as B5 (suspicious for malignancy) and 20 (1.8%) as B6 (malignant). When comparing the sonographic features of nodules with benign cytology (category B2) vs those of nodules with cytology category B3-6, irregular shape and ill-defined margins of the nodule, and microcalcifications and the hypoechogenicity increased significantly the possibility for a B3-B6 cytology result (p<0.05). Finally, there was no association of gender and age with the (B) category results.

The aforementioned sonographic findings decrease the possibility for a benign cytology result according to the Bethesda classification system. Key words: Bethesda classification system, fine needle aspiration biopsy, thyroid nodules, thyroid ultrasound.