Background. Fine-needle aspiration cytology (FNAC) is diagnostic standard for thyroid nodules. However, the influence of size on FNAC accuracy remains unclear especially in too small or too large thyroid nodules. The objective of this retrospective cohort study was to investigate the effect of nodule size on FNAC accuracy.Methods.All consecutive patients who underwent thyroidectomy for nodules in 2010 were enrolled. FNAC results (according to the Bethesda system) were compared to pathological diagnosis. The nodules were categorized into groups A–E on the basis of maximal diameter on ultrasound (≤0.5, >0.5–1, >1-2, >2–4, and >4 cm, resp.).Results.There were 502 cases with 690 nodules. Overall FNAC sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.4%, 98.2%, 99.4%, 86.4%, and 96.0%, respectively. False-negative rates (FNRs) of groups A–E were 3.2%, 5.1%, 1.3%, 13.3%, and 50%, respectively. Accuracy rates of groups A–E were 96.8%, 94.8%, 99%, 94.7%, and 87.5%, respectively.Conclusion.Although accuracy rates of FNAC in thyroid nodules smaller than 0.5 cm are comparable to the other group, thyroid nodules larger than 4 cm with benign cytology carry a higher risk of malignancy, which suggest that those should be considered for intensive follow-up or repeated biopsy.

The persistence of neck scarring is a common concern among patients undergoing thyroidectomy. Botulinum toxin A (BTA (Botox)) has been shown to suppress scar enlargement at the incision site. The objective of this study was to evaluate the effect of intraoperative Botox administration on neck scarring after thyroidectomy. A prospective double-blind randomized clinical trial was performed in patients undergoing conventional thyroidectomy. Forty patients were randomly allocated to a Botox or a control group (both, n = 20). The wound was closed after injection into the platysma muscle of 50 U of Botox diluted in 1 mL of normal saline or 1 mL of saline alone. Skin scars were assessed using the modified Stony Brook Scar Evaluation Scale (SBSES) and Manchester Scar Scale (MSS) at 1, 12, and 24 weeks postoperatively. The SBSES and MSS scores of the Botox group were significantly better than those of the control group (p = 0.034 and p = 0.039). At 24 weeks postoperatively, the SBSES and MSS scores were significantly better in the Botox group (p = 0.006 and p = 0.030). BTA injected into the incision site can suppress postoperative scar formation and thereby improve the cosmetic outcome.