The number of patients suffering from thyroid nodules is increasing, and sometimes they are very nervous about whether the nodules are cancerous because they cannot get a clear treatment plan from the doctor. Nowadays, the nature of the pathology can be clarified by ultrasound-guided fine needle aspiration technique FNAB of the thyroid lesion.
Patients should not swallow or speak during FNAB to minimize movement of the thyroid gland. The neck is sterilized, the ultrasound probe is placed in the best position where the nodule can be seen, and FNAB is performed using a 27G needle under continuous ultrasound guidance. The puncture specimen is examined in the pathology department. After the biopsy is completed, local pressure bandage is applied and the patient can leave the hospital after feeling no discomfort.
1. What kind of nodules require FNAB?
Indications for FNAB combining ultrasound and clinical manifestations
Ultrasound/clinical manifestations
Indications for FNAB
Solid nodules
Solid nodules with suspicious ultrasound findings, especially microcalcifications
≥25px
Solid nodules without suspicious ultrasound findings
≥37,5px
Mixed cystic nodule with suspicious ultrasound
≥37,5px
Mixed cystic solid nodule without suspicious ultrasound
≥50px
Spongy nodule
≥50px
Simple cystic without any of the above mentioned features
FNAB not required
Solid portion >50% greater than initial ultrasound
FNAB indications
Suspected cervical lymph nodes
FNAB lymph nodes with/without nodules
Multiple nodes
Normal tissue spacing
FNAB for more than four suspicious nodes, if no suspicious nodes, biopsy of the largest node may be considered
No normal tissue spacing
FNAB is not required
Rapidly and diffusely enlarging thyroid
FNAB to rule out undifferentiated carcinoma, lymphoma, or metastasis
People at high clinical risk for thyroid cancer
For this group, the criteria for FNAB indication may be reduced (e.g., threshold >12, 5px for suspicious solid nodules)
History of radiation exposure in childhood or adolescence
FDG-concentrated nodules on PET
Age <15 or >45, especially in men
History of thyroid cancer with lobectomy on one side
Have a thyroid cancer patient in the immediate family
Personal history of thyroid cancer (familial adenomatous polyposis, Kanai’s syndrome, Cowden’s syndrome, or type II multiple endocrine adenoma (Sepulcher’s syndrome))
2. What is the accuracy of the FNAB results?
FNAB is a cytopathologic examination with a sensitivity of 92% (72-98%) and a false positive rate of 3% (0-7%) for the diagnosis of thyroid cancer by fine needle aspiration technique of ultrasound-guided thyroid lesions FNAB. The false-negative rate is less than 0,6% and is a reliable method for the diagnosis of papillary, medullary and poorly differentiated cancers. Preoperative FNAB can help reduce unnecessary thyroid nodule surgery and help determine the appropriate treatment plan.
Tip: Approximately 10-15% of cases may be poorly sampled and require a repeat ultrasound or FNAB in 3 months.
3. What preparation is needed for FNA?
Patients are required to have routine blood tests, coagulation function and ECG before FNAB, and no fasting is required.
Patients should not swallow or speak during FNAB to reduce the movement of the thyroid gland. The neck is sterilized, the ultrasound probe is placed in the best position where the nodule can be seen, and FNAB is performed under continuous ultrasound guidance using a 27G needle. The puncture specimen is examined in the pathology department. After the biopsy is completed, local pressure bandage is applied and the patient can leave the hospital after feeling no discomfort.
4.Appointment process
Outpatients can go to our oncology surgery and general surgery clinics with the ultrasound report of our hospital or other hospitals (contact number: 057466623721) to ask whether FNAB is needed.
FNAB examination time and place: Every Tuesday afternoon in the ultrasound department on the fourth floor of the special examination building.