Who Performs Thyroid Fine Needle Biopsy
Thyroid fine needle aspiration biopsy (FNA) should be performed by a trained operator using ultrasound guidance, with the procedure typically conducted by radiologists, endocrinologists, or surgeons who have expertise in ultrasound-guided needle procedures. 1, 2
Procedural Requirements and Operator Qualifications
Ultrasound guidance is mandatory for thyroid FNA, as this is the preferred method recommended by multiple guidelines due to superior accuracy, economy, safety, and effectiveness compared to palpation-guided techniques 1, 2
The procedure requires an operator skilled in both ultrasound imaging and needle aspiration technique, as proper sampling technique (taking samples circumferentially at the periphery of the nodule) is critical to avoid false negatives from central degeneration 3
An experienced cytopathologist must be available to interpret the specimens, as FNA interpretation requires specific expertise in thyroid cytology 4, 3
Common Clinical Settings
Radiologists frequently perform ultrasound-guided thyroid FNA in hospital radiology departments, particularly when imaging expertise is prioritized 5
Endocrinologists who are trained and motivated in FNA technique can develop the necessary skills quickly and often perform the procedure in outpatient settings 6, 7
Surgeons with ultrasound training may perform thyroid FNA as part of preoperative evaluation 4
Critical Quality Factors
The operator must obtain adequate sampling, defined as a minimum of 6 aspirates with at least 6 clusters of benign cells on each of at least 2 aspirates when benign disease is suspected 3
Multiple needle passes (3 passes) significantly improve specimen adequacy rates compared to single-pass techniques, reducing unsatisfactory biopsy rates from 33.8% to 13.7% 5
The presence of an on-site cytologist to prepare slides immediately improves diagnostic yield, though on-site microscopic assessment is not always available 5
Important Caveats
Avoid referring to providers without ultrasound capability, as palpation-guided FNA does not meet current guideline standards and has inferior accuracy 1, 2
The operator must work closely with a pathologist experienced in thyroid cytopathology, as follicular neoplasms may yield indeterminate results requiring surgical excision for definitive diagnosis 1, 2
False negatives cannot be entirely excluded even with experienced operators, though false positives are practically nil when proper technique is used 6