Efficacy of surgeon-performed, ultrasound-guided lymph node fine needle aspiration in patients with thyroid pathologic conditions

Digital Examination of LYmph node CYtopathology Using the Sydney system (DELYCYUS): An international, multi-institutional study

BACKGROUND

After a series of standardized reporting systems in cytopathology, the Sydney system was recently introduced to address the need for reproducibility and standardization in lymph node cytopathology. Since then, the risk of malignancy for the categories of the Sydney system has been explored by several studies, but no studies have yet examined the interobserver reproducibility of the Sydney system.

METHODS

The authors assessed interobserver reproducibility of the Sydney system on 85 lymph node fine-needle aspiration cytology cases reviewed by 15 cytopathologists from 12 institutions in eight different countries, resulting in 1275 diagnoses. In total, 186 slides stained with Diff-Quik, Papanicolaou, and immunocytochemistry were scanned. A subset of the cases included clinical data and results from ultrasound examinations, flow cytometry immunophenotyping, and fluorescence in situ hybridization analysis. The study participants assessed the cases digitally using whole-slide images.

RESULTS

Overall, the authors observed an almost perfect agreement of cytopathologists with the ground truth (median weighted Cohen κ = 0.887; interquartile range, κ = 0.210) and moderate overall interobserver concordance (Fleiss κ = 0.476). There was substantial agreement for the inadequate and malignant categories (κ = 0.794 and κ = 0.729, respectively), moderate agreement for the benign category (κ = 0.490), and very slight agreement for the suspicious (κ = 0.104) and atypical (κ = 0.075) categories.

CONCLUSIONS

The Sydney system for reporting lymph node cytopathology shows adequate interobserver concordance. Digital microscopy is an adequate means to assess lymph node cytopathology specimens.

Surgeon‐performed fine‐needle aspiration for lymph nodes behind the big cervical vessels in papillary thyroid cancer

Objective

This study aimed to describe the technique of surgeon‐performed ultrasound (US)‐guided fine‐needle aspiration (FNA) of cervical retrovascular lymph nodes in papillary thyroid cancer (PTC) patients and analyze its efficacy.

Methods

This study included consecutive patients with retrovascular suspicious lymph nodes who had FNA performed by surgeons. The technique and efficacy of four different puncture routes were assessed.

Results

A total of 102 lymph node FNAs were performed on 100 patients. None yield insufficient aspiration, while 2% of FNA cytology result in an indeterminate diagnosis. No severe complication was observed. Cytologic testing plus thyroglobulin washout indicated sensitivity, specificity, positive predictive value, and negative predictive value in diagnosing nodal metastasis were 99%, 93%, 97%, and 97%, respectively. There was no significant difference in the test accuracy of FNA through different routes.

Conclusions

In PTC patients, suspicious lymph nodes behind the big cervical vessels should not be considered a contraindication to FNA. They can be diagnosed safely and accurately using appropriate puncture routes.

Level of evidence: 4.

Standardization of thyroid fine needle aspiration procedure and outcomes within an endocrine surgery department

Background

Fine needle aspiration (FNA) biopsy is an essential procedure for thyroid nodules. Although, the efficacy of surgeon-performed thyroid FNA biopsies has been demonstrated in the literature, there are insufficient data regarding how to establish an efficient program with a low insufficiency rate within a group practice.

Methods

An endocrine surgery thyroid FNA biopsy program was established in 2000 by one surgeon, with training of additional partners during fellowship and upon recruitment. The results within 18 years were analyzed. The FNA biopsies were performed by endocrine surgeons under ultrasound guidance without on-site pathologist review.

Results

A total of 5,469 FNA biopsies were performed by 7 surgeons. The total number of FNA biopsies performed by each surgeon varied between 291-1,378. FNA biopsies were performed in 2 passes using 22-gauge needles under constant suction. The overall insufficiency rate was 4.3%, with individual surgeon rates ranging between 2.7% and 7.2%. The insufficiency rate for the whole team ranged between 3.3% and 5% when examined in 5-year blocks.

Conclusions

This study shows that an establishment of a highly efficient thyroid FNA biopsy program within a group practice is possible with a structured endocrine surgical training and adoption of a standard technique.

Thyroglobulin washout from cervical lymph node fine needle aspiration biopsies in patients with differentiated thyroid cancer: an analysis of different expressions to use in post-total thyroidectomy follow-up

INTRODUCTION

Although frequently used as an adjunct to cytology in patients with differentiated thyroid cancers, interpretation of thyroglobulin washout remains unclear. We aim to compare the utility of different analytic tools to develop recommendations for use in post-total thyroidectomy follow-up.

METHODS

This is an institutional review board-approved retrospective study of patients who underwent lymph node fine needle aspiration biopsy with thyroglobulin washout between 2012 and 2018, during the post-total thyroidectomy follow-up of differentiated thyroid cancer. The utilities of thyroglobulin washout concentration, thyroglobulin washout/serum thyroglobulin ratio, and absolute thyroglobulin content were compared.

RESULTS

Sixty-four patients underwent 79 fine needle aspirations with thyroglobulin washout of cervical lymph nodes. Fifty-two lymph nodes were found to be metastatic and 27 benign. One patient had a pathologically confirmed lymph node metastasis despite a thyroglobulin washout of 0. The optimal cutoffs of thyroglobulin washout, thyroglobulin washout/serum thyroglobulin ratio, and absolute thyroglobulin content to predict metastatic involvement were 2.5 ng/ml (94% sensitive, 100% specific), 0.1 (100% sensitive and specific), and 12.5 (94% sensitive, 100% specific), respectively. The second measure lacked utility in patients with undetectable serum thyroglobulin.

CONCLUSION

The use of thyroglobulin washout concentration or thyroglobulin washout/serum thyroglobulin ratio has drawbacks based on variations in technique and clinical scenario. Absolute thyroglobulin content is an alternative that may be a more objective expression of thyroglobulin washout.