Frozen Tissue Examination: Is It really no Longer of Use in Parathyroid Surgery? Single-center Retrospective Study on 97 Patients treated by minimally Invasive Approach
Authors: Furderer, Thomas , Bouviez, Nicolas , Paquette, Brice , Landecy, Gerard , Heyd Bruno , Vienney, Gabriel , Lakkis, Zaher , Tauziede Mael 
Published: August 2017

ABSTRACT

Introduction
Surgery, by minimally invasive approach, has become the gold standard in the treatment of primary hyperparathyroidism. However, the preoperative and intraoperative examinations to be performed are still subject to debate. The frozen tissue examination of the parathyroidectomy specimen is often criticized, as it is deemed difficult and noninformative in case of multiglandular disease. The primary objective was to study the result of the frozen tissue examination and its benefit in the operative strategy in minimally invasive surgery.

Materials and methods
This is a single-centre retrospective descriptive study on patients who underwent surgery for primary hyperparathyroidism between January 2011 and September 2013 at Besançon Centre Hospitalier Régional Universitaire (CHRU) [Regional University Hospital Center]. Inclusion criteria consisted of: At least one contributory preoperative imaging test, a focused approach, and an intraoperative frozen tissue examination with microscopic analysis of the surgical specimen.

Results
A total of 157 patients were treated for hyperparathyroidism and 97 were enrolled in the study. The mean age was 62.3 ± 13.7 years, mean serum calcium was 2.81 ± 0.24 mmol/L and the mean parathyroid hormone (PTH) level was 175 ± 120 pg/mL. Around 53 patients (54.6%) had concordant scintigraphic and ultrasound examinations while 20 patients (20.6%) had an isolated contributory scintigraphic examination, 21 patients (21.6%) had an isolated contributory cervical ultrasound and 3 patients had discordant examinations. The sensitivity of the preoperative imaging in case of concordance was 84.9% for the location of the diseased gland, and 92.4% for its lateralization. The sensitivity to ultrasound alone and scintigraphy alone was 61.9% and 65% respectively. Nearly 23 false positive imaging results were found in which 11 were corrected during surgery by the surgeon based on the macroscopic appearance. The frozen tissue examination of the surgical specimen changed the surgical strategy in 12 cases (12.4%): Six results of normal parathyroid gland (50%), four results of thyroid tissue (33.3%), and two cases of hyperplastic gland (16.7%). The results of the frozen tissue examination thus led to 12 exploratory cervicotomies, which revealed three ipsilateral adenomas (25%), six contralateral adenomas, and one adenoma included in the thyroid lobe, and enabled the surgeon to perform two subtotal parathyroidectomies for parathyroid hyperplasia. The mean duration of the frozen tissue examination was 24.2 ± 8.6 minutes and the cure rate is 100% for the population treated by minimally invasive approach.

Conclusion
In our experience, the frozen tissue examination enabled the surgeon to intraoperatively correct 12 erroneous imaging diagnoses, including two cases of parathyroid hyperplasia and thus to continue the exploration of other glands and immediately carry out the appropriate treatment. This is an interesting technique, but it is conditioned by the pathologist’s expertise.

How to cite this article
Furderer T, Bouviez N, Paquette B, Landecy G, Heyd B, Vienney G, Lakkis Z, Tauziede M. Frozen Tissue Examination: Is It really no Longer of Use in Parathyroid Surgery? Single-center Retrospective Study on 97 Patients treated by minimally Invasive Approach. World J Endoc Surg 2017;9(2):55-60.