The accuracy of frozen section diagnosis of pulmonary nodules: evaluation of inflation method during intraoperative pathology consultation with cryosection.

INTRODUCTION: Intraoperative frozen section diagnosis (FSD) is a very important pathologic examination that can determine the extent of the subsequent surgical procedure. However, FSD is especially difficult in small pulmonary nodules due to severe architectural distortion during cryosection. This study was undertaken to determine the accuracy of FSD of pulmonary nodules and to evaluate the inflation method during cryosection.
METHODS: We retrospectively reviewed FSD of 229 consecutive pulmonary nodules and evaluated the diagnostic accuracy and efficacy of inflation method during cryosection. Since August 2006, all frozen sections (165, 72.1%) were made after inflation with optimally diluted embedding medium.
RESULTS: The FSD were as follows: nonneoplastic lesions (29, 12.7%), benign neoplasms (28, 12.2%), and malignant neoplasms (172, 75.1%). The proportion of the lesions smaller than 2 cm was 60.3% (138 of 229). The frozen section quality of lung tissue was excellent after inflation with diluted embedding medium. Inflated lung specimens harboring minute lesion displayed distinct gross appearance, which could not be palpated. Histologically, open air spaces and normal parenchymal architectures were well preserved. Minute precancerous foci such as atypical adenomatous hyperplasia and bronchioloalveolar carcinoma could be readily identified. After using inflation method during cryosection, both the sensitivity and specificity reached 100%, and the incidence of intraoperative pathology consultation increased markedly, especially small impalpable lesions.
CONCLUSIONS: The accuracy of FSD and histologic qualities were excellent by using inflation method, especially in cases of impalpable small precancerous lesions. The pathologist could guide with confidence the surgeon in planning the surgical management.