Intraoperative thyroid frozen section: indications, results and consequences

Jesper Gern; Michael Arbogast; Hakan Alakus; Stefanie Brunner; Matthias Schmidt; Michael Faust; Christiane Josephine Bruns; Anne Maria Schultheis; Costanza Chiapponi

doi:10.21037/gs-23-105

Intraoperative thyroid frozen section: indications, results and consequences

Gland Surg. 2024 May 30;13(5):630-639. doi: 10.21037/gs-23-105. Epub 2024 May 23.

Authors

Jesper Gern^#^{1

2

3}, Michael Arbogast^#^{1

2

3}, Hakan Alakus^{1

3}, Stefanie Brunner^{1

2

3}, Matthias Schmidt^{3

4}, Michael Faust^{3

5}, Christiane Josephine Bruns^{1

2

3}, Anne Maria Schultheis^{3

6}, Costanza Chiapponi^{1

2

3}

Affiliations

¹ Department of General, Visceral, Cancer and Transplant Surgery, University Hospital of Cologne, Cologne, Germany.
² Department of General and Visceral Surgery, Evangelisches Klinikum Köln Weyertal, Cologne, Germany.
³ Medical Faculty of the University of Cologne, Cologne, Germany.
⁴ Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany.
⁵ Policlinic for Endocrinology, Diabetes and Preventive Medicine, University Hospital Cologne, Cologne, Germany.
⁶ Department of Pathology, University Hospital Cologne, Cologne, Germany.

^# Contributed equally.

Abstract

Background: Frozen section (FS) analysis is strongly influenced by the experience of surgeons and pathologists. We analyzed its performance in a secondary care hospital with surgical and pathologic experience transferred from a university hospital.

Methods: Indications, results, and consequences of all thyroid FS performed between January 1, 2021 and December 31, 2022 were critically reviewed.

Results: FS was performed in 90 (26.5%) of 340 procedures. Indications consisted in a suspicious fine needle biopsy in 28 (31.1%) cases, (99m) Technetium-Methoxy-Isobutyl-Isonitrile (MIBI) retaining hypofunctional nodules in 25 (27.8%), the intraoperative appearance in 18 (20%), the sonographic appearance in 18 (20%) and a positron emission tomography (PET) positive result in 1 case (1.1%). Malignancy was diagnosed in 21 (23.3%) and confirmed by final histology in all cases (100%). In the remaining 69 (76.7%) FS displaying no positive malignancy criteria, final histology delivered benign in 62 (89.8%) and malignant diagnoses in 7 cases (10.1%). 25% of thyroid carcinomas could not be diagnosed by FS. FS sensitivity was consequently 75% (95% CI: 55.1-89.3%). All missed malignancies were papillary thyroid carcinomas of follicular variant (fvPTC). FS sensitivity was lowest in MIBI positive hypofunctional nodules (33%) and Bethesda III (50%) as opposed to Bethesda V (92.9%) and to those cases with suspicious sonographic or intraoperative appearance (71.4%). Two-staged surgery was necessary in 10 (15.8%) of carcinomas.

Conclusions: Sensitivity of FS in a secondary care hospital offering surgical and pathologic experience from a specialized university center is 75% and mainly reduced by the prevalence of fvPTC. Omitting FS in Bethesda III and MIBI positive hypofunctional nodules might improve FS performance.

Keywords: Thyroid surgery; intraoperative frozen section (intraoperative FS); thyroidectomy.