Introduction. Medullary thyroid carcinoma (MTC) is not a common type of thyroid cancer but a dangerous one. Therefore, early diagnosis is of utmost importance. That in mind, we decided to determine how well thyroid ultrasound (US) and fine-needle aspiration (FNA) perform in detection of MTC. Methods. A total of 76 MTC cases from 2004 to 2017 were analyzed in Kaunas Clinics. In all cases diagnosis was verified by histological evaluation. Patients’ age, gender, presence of Type 2 Multiple Endocrine Neoplasia (MEN2 syndrome), sonographic features of thyroid nodules and results of cytologic and histologic evaluation were assessed.
Results. In 38 of the cases MTC was located in the left lobe of thyroid gland (50%), right lobe – 28 (36.8%), bilaterally – 10 (13.2%). MEN2 syndrome was diagnosed in 9 of the MTC cases (11.8%). In 66.7% of MEN2 syndrome cases MTC was bilateral. 55 thyroid nodules (72.4%) were hypoechoic, 48 (63.16%) had irregular or lobulated margins, 41 (53.95%) were taller-than-wide, 33 (43.42%) had microcalcifications, 65 (85.53%) were solid, mean size was 2.75 ± 1.68 cm. Thyroid US had sensitivity of 89.24% in predicting malignancy. FNA findings were distributed as follows: 6 (7.89%) benign, 52 (68.42%) suspicious, 7 (9.21%) malignant, 4 (4.27%) nondiagnostic, 7 (9.21%) follicular neoplasm. FNA had sensitivity of 81.94% in detecting MTC. Mean size of thyroid nodules measures during histologic evaluation was 2.63 ± 1.7 cm. Positive correlation (r = 0.87, p < 0.001) was found between sizes of thyroid nodules measured during thyroid US and hystologic evaluation.
Conclusions. In our study we concluded that MTC presented itself more often as a solitary nodule. In cases of MEN2 syndrome, bilateral medullary thyroid cancer was more common. Both thyroid US and FNA were sensitive in predicting malignancy. Thyroid nodule size measured during thyroid US correlated strongly with histological measurements.