Is fine needle aspiration really not necessary in patients with thyroid nodules ≤ 1 cm with highly suspicious features on ultrasonography and candidates for active surveillance?

BACKGROUND: The low rate of progression associated with the potential complications of thyroidectomy makes active surveillance an increasingly recommended management in low-risk papillary microcarcinomas of the thyroid (PMT). The objective of this study was to report the results of fine needle aspiration (FNA) of nodules ≤ 1 cm with highly suspicious appearance on ultrasonography (US) in patients who are potential candidates for active surveillance.

METHODS: We revised thyroid nodules ≤ 1 cm with highly suspicious appearance on US in patients without known distant metastases, suspicion of extrathyroid extension, or suspicious lymph nodes on US. FNA was guided by US. All patients were referred for surgery, except for those with benign cytology (on two occasions).

RESULTS: There were 181 patients with 198 nodules ≤ 1 cm that were highly suspicious and apparently restricted to the thyroid on US. Initial cytology was benign in 76 nodules (38.4%). Among these 76 nodules, repetition of FNA confirmed the benign nature in 59 (29.8%). Initial cytology was insufficient, indeterminate, suspicious of papillary thyroid cancer (PTC) and malignant (PTC) in 5, 15, 12, 9, and 80 nodules, respectively. FNA revealed medullary carcinoma in one patient. All 90 suspicious or malignant nodules were carcinomas on histology and 22 (81.4%) of the 27 nodules with indeterminate cytology were malignant.

CONCLUSIONS: FNA changed the "presumptive" diagnosis of PMT in 30% of nodules. Diagn. Cytopathol. 2017;45:294-296. © 2016 Wiley Periodicals, Inc.