Impact of fine needle aspiration cytology on the management of solitary thyroid nodules.

To evaluate the impact of the routine use of fine needle aspiration cytology (FNAC) on the management of solitary thyroid nodules, 102 consecutive patients were assessed in regard to the proportion of patients being subjected to surgery and the corresponding yield of malignancy. This cohort was compared with a historical control where FNAC was not routinely applied as a diagnostic selection criterion. The percentage of patients operated on had decreased from 95% to 60% (P less than 0.001) without any significant decrease in the field of malignancy: 18.6% vs 17.6% (P = 0.97). The yield of malignancy of patients operated on had increased from 18.4% to 26.2%. Of those not subjected to surgery, 14 patients or 14% of the original cohort experienced spontaneous complete resolution of their nodules after a mean follow-up period of 5.5 months (s.d. = 3.5) (non-resected group). In the retrospective evaluation of diagnostic discriminants to maximize yield of malignancy while minimizing unnecessary surgery for thyroid nodules, the use of combined parameters of clinical suspicion, positive FNAC and age greater than or equal to 50 years detected 100% of malignancies with only 50% of patients requiring surgery. This was superior to other modalities including clinical parameters and expensive investigations of radionuclide scans and ultrasonography. In conclusion, the use of FNAC in the evaluation of solitary thyroid nodules has resulted in a decreased proportion of patients requiring surgery and cost saving while maintaining the yield of malignancy.