Thyroid Nodule Biopsy/ Cytology 101: What clinical management decisions are associated with the 6 Bethesda Reporting groups?
DR. Guttler’s comments on the Bethesda reporting system. My comments follow the description of each category.
What you need to know about each of the six.
- The most important is the ROM( risk of malignancy ) management recommendations.
- Bethesda 1 ND/UNS non-diagnostic unsatisfactory ROM 5-10% recommend repeat FNA with US guidance. I suggest you have expert FNA physicians who use of rapid adequacy assessment to decrease inadequate results. Radiologists are bad at adequacy because they use large er needles and stay in the nodule too long obtaining bloody samples devoid of cells or cells clumped in fibrin resulting in an over diagnosis of complex 3 D follicular lesion.
- Bethesda 2 B benign 0-3 % Clinical and US follow up. A good quality FNA can result in a benign diagnosis that is strong evidence it is not cancer in 97-100 % of the cases.
- Bethesda 3 AUS/FLUS atypia and or folicular lesion undetermined significance 6-18% Repeat FNA,molecular testing or lobectomy. The addition of NIFT-P a comment is added. ” rare atypical nuclear features in this follicular patterned lesion suggests the possibility of Follicular variant of Papillary cancer or NIFT-P. The key to this category is molecular marker testing. Several labs offer it.I use Interpace DX but there are several more. I do not use the ones with just classifiers.
- Bethesda 4 FN/SFN follicular neoplasm or suspicious for FN 10-40% molecular testing lobectomy. This can be a problem when bloody smears are called follicular neoplasms. Have expert review the smears and if they are distorted by blood and fibrin , a repeat should be done with molecular tests.
- Bethesda 5 SM suspicious for maliganacy 45-60% near-total or lobectomy. There are things that can go wrong with both 5, and 6. Suspicious or diagnostic for cancer can be wrong. We have seen the wrong cancer diagnosed as 5, or 6. This resulted in the wrong surgery, and radiation therapy. The rare Medullary thyroid cancer can be miss-diagnosed as Hurthle cell or follicular cancers, and the chance to do the correct first surgery will be missed, and prevent radiation surgery.
- Bethesda 6 M malignant 94-96% near-total or lobectomy. I have seen biopsy proven stage 6 thyroid cancer at needle biopsy called benign at surgery. One was called Hashimoto’s instead of variant papillary with lymphocytes, and a follicular variant papillary thyroid cancer called follicular adenoma.
What about inadequate biopsies?
Can’t get cells: Fibrous tumors, schwannomas, fibrotic Hashimoto’s, or Reidels.
Operator is the main cause of bad biopsies due to poor technique. > 10% inadequate the operator needs re-training.Radiologists are the main problem as they get too many bloody samples and too high inadequate rates. Surgeons and ENT are next followed by endocrinologists.All need training in biopsy technique.
Poor specimen quality causes false negative and false positive results. These can lead to unnecessary surgery with the morbidity associated parathyroid and vocal nerve damage. Rapid Adequacy Assessment ROSE can help decrease ND/UNS.
Also there are alternative therapy options for micro-papillary thyroid cancer with active surveillance , ethanol ablation PEI or radiofrequency ablation RFA to ablate the small cancer in the thyroid gland without surgery or radioiodine.
Richard Guttler MD,FACE,ECNU
Come to see me for outside opinions and re-biopsies with molecular marker testing.
Call 310-393-8860 or email@example.com for details.