A simple inflation method for frozen section diagnosis of minute precancerous lesions of the lung

doi:10.1016/j.lungcan.2007.08.023

Lung Cancer

Volume 59, Issue 2, February 2008, Pages 198-202

https://doi.org/10.1016/j.lungcan.2007.08.023 Get rights and content

Summary

Background

Recently, the demand for intraoperative pathology consultation for small pulmonary nodules including ground-glass opacity (GGO) has been increasing. Evaluation of minute precancerous lesions of the lung by frozen section is very difficult for the pathologist as uninflated lung tissue usually shows severe atelectasis and frozen artifact. We tried to inflate lung tissue with the embedding medium used for frozen section and to determine the appropriate dilution ratio of the embedding medium for optimization of frozen section morphology.

Methods

The lung specimens were derived from 10 patients who underwent video-assisted thoracoscopic surgery (VATS) due to pneumothorax (four patients) and GGO (six patients) detected on high-resolution computed tomography (HRCT) at Seoul National University Bundang Hospital. The pneumothorax specimens were divided into six groups—uninflated, inflated with saline, and inflated with embedding medium (not diluted, 1:1, 2:1 and 2:3). The qualities of the frozen sections were compared with corresponding permanent paraffin sections. Lung specimens obtained from the six people with GGO detected on HRCT were submitted for intraoperative pathology consultation. Frozen sections were made after inflation with optimally diluted embedding medium determined by the above experiment with pneumothorax specimens, and the frozen section diagnoses (FSD) were compared with the final pathologic diagnoses of corresponding permanent paraffin sections.

Results

The frozen section quality of lung tissue was excellent after simple inflation with diluted embedding medium (2:3). Minute precancerous foci such as atypical adenomatous hyperplasia (AAH) and bronchioloalveolar carcinoma (BAC) could be readily identified in frozen sections using this method. Of the six patients with solitary GGO, four were diagnosed as BAC, nonmucinous type and two were as AAH on the frozen sections. Intraoperative FSD corresponded well with final diagnoses obtained with paraffin sections.

Conclusions

An inflation procedure using diluted embedding medium can make lung tissue expand well during frozen section. Minute and even nonpalpable GGO lesions could be detected more easily by this technique in frozen sections, which would be helpful in determining how extensive a surgical procedure needs to be. Application of this procedure appears to improve the accuracy of FSD of minute precancerous pulmonary nodules.

Introduction

The detection rate of minute pulmonary nodules suggestive of lung cancer or atypical adenomatous hyperplasia (AAH) in the peripheral lung parenchyma is increasing due to the widespread use of computed tomography (CT) in clinical practice [1]. Preoperative diagnosis of these minute nodules by transbronchial or transthoracic biopsies can be difficult due to sampling problems [2], [3]. The demand for intraoperative pathology consultation for these minute pulmonary nodules including ground-glass opacity (GGO) has been increasing. Frozen section diagnosis (FSD) is especially difficult in lesions less than 1 cm in size because they may not be detected by palpation [3], and even worse, cryosections of deflated lung tissue show complete collapse of the architectural morphology. Apparent hypercellularity and thickening of alveolar walls become evident in such tissues and may mimic alveolar hyperplasia. Frozen sections of minute precancerous lesion presenting with GGO on CT are very difficult to interpret, as reactive epithelial changes can mimic a malignancy. The surgical pathologist is hence presented with a dilemma; whether to make an intraoperative diagnosis of malignancy based on atypical changes that could be artificially exaggerated by the technical artifacts of the frozen section procedure, or to defer the diagnosis until permanent paraffin sections can be examined. A diagnosis such as “atypia, defer to permanent sections” when examining minute precancerous lesions on frozen section is often favored by the surgical pathologist, as it avoids possible diagnostic mistakes and potential medico-legal exposure [3]. However, this equivocal FSD delays the correct diagnosis of minute pulmonary lesions and may subject the patient to a second operation after permanent pathologic diagnosis. It has been widely accepted that formalin inflation of lung specimens greatly improves histologic examination [4]. However, this method could not be applied to frozen section because the sections tend to be torn into shreds during cryosectioning. Therefore it is imperative to devise a technique that facilitates pathologists to make FSD of the small pulmonary nodules with confidence. This report describes a simple, easy and quick procedure that preserves the original dimensions of lung specimens for frozen section, allowing correct histological evaluation.

Section snippets

Materials and methods

The lung specimens were derived from 10 patients who underwent video-assisted thoracoscopic surgery (VATS) due to pneumothorax or ground-glass opacity (GGO) on high-resolution computed tomography (HRCT) at Seoul National University Bundang Hospital between June 2006 and April 2007. Subjects were studied according to the guidelines of the Committee of Medical Ethics of the Seoul National University Bundang Hospital, Korea, and gave informed consent. None of the 10 cases were pathologically

Determination of optimal dilution ratio of embedding medium inflation

The appearance of embedding medium-inflated lung tissue was markedly different from that of uninflated lung tissue on frozen section (Fig. 1). Uninflated lung tissue showed marked artificial atelectasis mimicking hypercellularity such as interstitial cellular infiltration. The same lung tissue inflated with diluted embedding medium demonstrated a much more expanded lung structure as compared to uninflated or saline infused tissue. Inflation of the lung with embedding medium without dilution or

Discussion

The detection rate of small nodules in the lung parenchyma has been increasing due to the widespread use of CT screening for lung cancer (1). Small pulmonary nodules are frequently first diagnosed by frozen section, followed by lobectomy or limited resection (3). Intraoperative FSD is a very important pathologic examination that can determine the extent of the subsequent surgical procedure. However, frozen section of deflated lung specimens results in the collapse of parenchymal tissue and

Conflict of interest statement

All authors declare that we do not have any actual or potential conflict of interest including any financial, personal or other relationships with other people or organizations within 3 years of beginning the work submitted that could inappropriately influence our work.

Acknowledgements

The authors wish to express their gratitude especially to Ju Hyuk Park, M.T., and Haeryoung Kim, M.D., Department of Pathology, Seoul National University Bundang Hospital, for his excellent technical assistance and her critical comment of this manuscript.

References (5)

P. Mazzone et al.
Bronchoscopy and needle biopsy techniques for diagnosis and staging of lung cancer
Clin Chest Med
(2002)
S.J. Swensen et al.
Screening for lung cancer with low-dose spiral computed tomography
Am J Respir Crit Care Med
(2002)

There are more references available in the full text version of this article.

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