Management of thyroid follicular proliferation: an ultrasound-based malignancy score to opt for surgical or conservative treatment.

This study was conducted to evaluate whether ultrasound characteristics of thyroid nodules with a known cytologic diagnosis of "follicular pattern" (indicative of follicular hyperplasia, follicular adenoma or follicular carcinoma) can be used to define a nodule malignancy score to limit surgery to selected, higher-risk cases. In pre-operative ultrasound results of patients diagnosed with a "follicular pattern" on cytology who subsequently underwent surgery, each nodule feature was given a score from 0 (most likely benign) to 2 (most likely malignant), resulting in a total score ranging from 0 to 11. The total nodule score (total malignancy score) was then compared with the definitive histologic diagnosis. According to our results, surgery is advisable in patients with score ≥4 (79% of carcinomas), ultrasound follow-up seems to be appropriate for patients with a score of 3 (21% of carcinomas) and no action is recommended for patients with score <3 (only benign nodules).