In the Journals

Results of repeat thyroid FNA mostly unchanged from initial biopsy

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September 23, 2015

Results of repeat thyroid fine-needle aspiration biopsy were often unchanged from a benign initial fine-needle aspiration result, according to recent study findings published in Thyroid.

“Current guidelines recommend a repeat thyroid ultrasound 6 to 18 months after the initial fine-needle aspiration (iFNA) and repeat fine-needle aspiration biopsy (rFNA) if there is documented nodule growth,” the researchers wrote. “The clinical value of this approach, however, is unclear.”

M. Regina Castro, MD, of the Mayo Clinic in Rochester, Minnesota, and colleagues conducted a retrospective review of medical records on 323 patients (81% women; mean age, 52.3 years) with 334 thyroid nodules seen at the Mayo Clinic who had a benign iFNA biopsy and rFNA biopsy between 2003 and 2013. The researchers sought to determine the clinical relevance of rFNA biopsy after a benign iFNA biopsy.

History of thyroid disease was not found in 86% of participants; 7.5% had Hashimoto’s thyroiditis, 1.8% had Graves’ disease and 5.1% had other thyroid diseases. Only two participants did not undergo rFNA.

The mean nodule size was 2.3 cm, with size information available for 313 nodules. Thirteen percent of nodules were larger than 4 cm, and 28.4% had at least one suspicious ultrasound feature.

Rapid growth at baseline or during follow-up was reported by 1% of participants. Most participants (93%) had serum thyrotropin levels between 0.3 mIU/mL and 5.5 mIU/mL, followed by less than 0.3 mIU/mL (4.2%) and greater than 5.5 mIU/mL (2.3%); 28 participants did not have available serum thyrotropin levels.

Mean time to rFNA was 3.1 years. Results of rFNA were most commonly benign (85.3%), followed by suspicious (7.2%), nondiagnostic (5.7%) and malignant (1.8%). Clinical management was changed in 9.5% after rFNA.

Among participants who underwent surgery, 4.1% had thyroid malignancy, and malignancy prevalence was 1.2% among the whole cohort.

 “Since at least half of the malignant results included nonthyroid malignancies in this potentially high-risk population, one should consider rFNA in patients with a known nonthyroid malignancy (particularly those that more frequently metastasize to the thyroid, such as melanoma, kidney, breast and lung cancers) and thyroid nodules that are growing,” the researchers wrote. “For most other patients, growth alone, in the absence of other clinical or sonographic features of concern, rFNA cytology rarely yields a different result and may, in many cases, lead to unnecessary surgical intervention. Good communication between members of the interdisciplinary team (clinician, radiologist and pathologist) may help circumvent some of the difficulties in the management of thyroid nodules.” – by Amber Cox

Disclosure: The researchers report no relevant financial disclosures.