Routine ultrasound-guided aspiration cytology for evaluation of palpable thyroid nodules in an endemic area: is it justified?

Abstract

Purpose: To prospectively evaluate the efficacy of routine ultrasound-guided fine-needle aspiration cytology (FNAC) of thyroid nodules in an endemic area and to analyze the factors influencing it.

Methods: Patients with thyroid nodules were randomly subjected to either conventional palpation-guided fine-needle aspiration cytology (PFNAC) or ultrasound-guided fine-needle aspiration cytology (USFNAC). The results of cytology were compared with the final histopathologic diagnosis in 112 patients who had undergone surgery. The performance of both methods was individually analyzed in solid nodules, cystic nodules, and solitary and multinodular goitres.

Results: Overall, USFNAC showed a significantly higher sensitivity (83.3% vs 54.6%, p < .001), positive predictive value (100% vs 85.7%, p < .001), and greater diagnostic accuracy (96.5% vs 89.1%, p = .052) compared with PFNAC. The sensitivity of USFNAC was significantly higher compared with that of PFNAC in cystic and complex nodules (75% vs 50%, p < .001) but not in solid nodules (77.8% vs 75%, p > .05). USFNAC was more sensitive and more accurate than PFNAC for detection of malignancy in multinodular goitres (66.7% vs 50%, p < .05; 95.6% vs 86.2%, p < .05, respectively).

Conclusion: The superiority of "routine" USFNAC over PFNAC is mainly due to its better performance in cystic nodules and multinodular goitres. Hence, routine USFNAC can be recommended in areas where such lesions constitute the majority of thyroid nodules.