Solitary nodular goiter: Role of ultrasonography in fine-needle aspiration cytology diagnosis

ABSTRACT

Purpose: To assess the contribution of ultrasonography to the fine-needle aspiration cytology diagnosis of solitary nodular goiters [SNG]. 759 cases of SNG detected by ultrasonography were subjected to fine-needle aspiration. The age of the patients ranged from 9 to 92 years with a median of 35 years. Malefemale ratio was 135624. May-Gr'nwald-Giemsa-stained smears were reviewed and the cytodiagnosis was correlated with clinical and ultrasonographic findings. The right lobe of the thyroid was more frequently involved [52.3% cases] by solitary nodules compared to the left lobe [33.9% cases] and isthmus [13.8% cases]. 27% of SNG cases missed at clinical examination could be detected because of ultrasonography. The frequency of solid echotexture in colloid goiter without cytologic evidence of cystic degeneration [60.3%] was significantly higher than that observed in colloid goiter with cystic degeneration [32.6%, p < 0.001]. The difference of solid echotexture between hyperplastic nodules [55.4%] and colloid goiter [38.5%] was also statistically significant [p < 0.02]. The frequency of solid echotexture and homogeneous hypoechoic pattern in neoplastic goiter [65.4 and 21.2%, respectively] was significantly higher than that in nonneoplastic lesions [43.3 and 8.6%, respectively, p < 0.01]. Ultrasonography, besides its use in the detection of solitary nodules and selection of appropriate areas for aspiration, correlated with cytological interpretation in the majority of cases. However, ultrasonography cannot replace cytologic diagnosis as the specificity and positive predictive values are not sufficiently accurate