Long-term assessment of a multidisciplinary approach to thyroid nodule diagnostic evaluation

The diagnostic evaluation of patients with thyroid nodules is imprecise. Despite the benefits of fine-needle aspiration (FNA), most patients who are referred for surgery because of abnormal cytology prove to have benign disease. Recent technologic and procedural advances suggest that this shortcoming can be mitigated, although few data confirm this benefit in unselected patients.

A total of 2587 sequential patients were evaluated by thyroid ultrasound and were offered ultrasound-guided FNA (UG-FNA) of all thyroid nodules that measured > or =1 cm during a 10-year period. Results of aspiration cytology were correlated with histologic findings. The prevalence of thyroid cancer in all patients and in those who underwent surgery was determined. Surgical risk was calculated.

Tumors that measured > or =1 cm were present in 14% of patients: Forty-three percent of patients had tumors that measured <2 cm in greatest dimension, and 93% had American Joint Committee on Cancer stage I or II disease. The cytologic diagnoses 'positive for malignancy' and 'no malignant cells' were 97% predictive and 99.7% predictive, respectively. Repeat FNA of initial insufficient aspirates, as well as more detailed classification of inconclusive aspirates, improved preoperative assessment of cancer risk and reduced surgical intervention. Fifty-six percent of patients who were referred for surgery because of abnormal cytology had cancer compared with from 10% to 45% of patients historically. An analysis of operative complications from a subset of 296 patients demonstrated a 1% risk of permanent surgical complications.

The current findings demonstrated the benefits of UG-FNA and of a more detailed classification of inconclusive aspirates in the preoperative risk assessment of thyroid nodules, supporting adherence to recently published guidelines.