From the Guidelines
To order a fine needle aspiration (FNA) biopsy for a thyroid nodule, first consult with an endocrinologist or refer the patient to an interventional radiologist or surgeon who performs this procedure, as recommended by the most recent guidelines 1. The referral should include relevant clinical information such as nodule size, characteristics, and any concerning symptoms. Prior to the FNA, obtain thyroid function tests including TSH, free T4, and possibly free T3 to assess thyroid function, as suggested by previous studies 1. Additional recommended labs include calcitonin (to screen for medullary thyroid cancer, especially if there's a family history) and thyroid antibodies (anti-TPO and anti-thyroglobulin) if autoimmune thyroid disease is suspected. Ultrasound imaging of the thyroid should be performed before the FNA to characterize the nodule and guide the biopsy, as recommended by the latest guidelines 1. The decision to perform FNA is typically based on nodule size (usually >1 cm), ultrasound characteristics suggesting malignancy, or concerning clinical features. After the procedure, the sample will be sent for cytological examination, and in some cases, molecular testing may be recommended for indeterminate nodules, as suggested by recent studies 1. Patients should be advised to avoid blood thinners for several days before the procedure and to expect mild discomfort during the biopsy, which typically takes only a few minutes to perform. Some key points to consider when ordering an FNA biopsy for a thyroid nodule include:
- Nodule size: usually >1 cm
- Ultrasound characteristics: hypoechogenicity, microcalcifications, absence of peripheral halo, irregular borders, solid aspect, intranodular blood flow, and shape (taller than wide)
- Concerning clinical features: history of head and neck irradiation, family history of thyroid cancer, suspicious features at palpation, presence of cervical adenopathy
- Laboratory tests: TSH, free T4, free T3, calcitonin, thyroid antibodies (anti-TPO and anti-thyroglobulin)
- Molecular testing: may be recommended for indeterminate nodules, as suggested by recent studies 1.
From the Research
Ordering a Fine Needle Aspiration Biopsy for Thyroid Nodule
To order a fine needle aspiration biopsy for a thyroid nodule, the following steps can be taken:
- Consult with a physician to determine if a fine needle aspiration biopsy is necessary based on the patient's medical history and the characteristics of the thyroid nodule 2
- Choose a laboratory that has experience with thyroid nodule fine needle aspiration biopsies and has a good reputation for accurate results
- Ensure that the laboratory uses ultrasound-guided fine needle aspiration biopsy, which can help to reduce the rate of nondiagnostic and false negative results 3, 4
Recommended Labs
The following labs may be recommended for fine needle aspiration biopsy of thyroid nodules:
- Labs that use ultrasound-guided fine needle aspiration biopsy, which allows for real-time visualization of the needle and can help to improve the accuracy of the results 4
- Labs that have experience with thyroid nodule fine needle aspiration biopsies and have a good reputation for accurate results
- Labs that use a standardized and meticulous technique for fine needle aspiration biopsy, which can help to lower the yield of nondiagnostic specimens and false-negative results 4, 5
Factors to Consider
When ordering a fine needle aspiration biopsy for a thyroid nodule, the following factors should be considered:
- The size and characteristics of the thyroid nodule, which can help to determine the likelihood of malignancy 6
- The patient's medical history, which can help to determine the likelihood of malignancy and the need for a fine needle aspiration biopsy 2
- The experience and reputation of the laboratory, which can help to ensure that the results are accurate and reliable 3, 4, 5