폐암의 진단에서 경기관지 침흡인술(TBNA)의 유용성에 대한 연구

Abstract

Objectives: Transbronchial needle aspiration (TBNA) is the newest technique to become available for use with the fiberoptic bronchoscope. But because it is associated with the technical difficulties and problems in the interpretation of cytologic examination, it carries the least application until now and its routine use just like forceps biopsy or washing is not recommended. Even though several indications have been suggested, the role of needle aspiration in the diagnosis of central lesion remains to be determined. The needle, however, would have the advantage of easy penetration through submucosal or peribronchial tissue layers that are difficult to access with biopsy forceps, it can have the unique diagnostic usefulness and it is a safe technique without any significant complications. The purpose of this study was to establish the diagnostic yield of TBNA, especially in patients with peribronchial or submucosal lesion or necrotic endobronchial lesion, to compare the yield to that of forcep biopsy. Methods: Sixty-seven patients who were found to have the lesions suggestive of peribronchial or submucosal tumor or necrotic endobronchial lesion during diagnostic fiberoptic bronchoscopy and fifty-two patients in whom primary or metastatic lung cancers were confirmed from January 1992 to December 1993 at Severance Hospital Yonsei University were included in this study. The TBNA always preceded all the other procedures in order to minimize the possibility of contamination of the aspirated specimen. Interpretation of TBNA result was done with four categories; ① carcinoma of definite cell type, ② carcinoma of uncertain cell type, ③ suspicious of malignancy, ④ negative or unsatisfactory, after correlating the biopsy result. Results: During this period, flexible fiberoptic bronchoscopic examination was done in 1,517 cases and TBNA in 4.4%. Of these patients of TBNA, 62.9% of lesions occurred in the right bronchi, 34.3% in the left bronchi, and 2.8% in the distal trachea. The difference of TRNA yield according to cell type or bronchoscopic appearance of lesion was not significant, but it showed the relatively better result in small cell carcinoma and metastatic lung cancer. The difference of the yield between TBNA and biopsy among any cell type or any bronchoscopic finding was not significant, but the difference between the yield of the biopsy alone and the biopsy combined with TBNA was statistically significant. The cases in which TBNA was the only diagnostic test that disclosed a malignant lesion were 15 (28.8%). For 5 patients in 10, repeated bronchoscopy could have been avoided if at initial bronchoscopy physicians had performed TBNA. Conclusion: Our findings suggest that TBNA is a safe technique that can significantly increase the diagnostic yield of fiberoptic bronchoscopy in the diagnosis of peribronchial or submucosal spread of bronchogenic carcinoma over that of forceps biopsy alone, and can be beneficial for suspected small cell carcinoma and pulmonary metastatic lesions. To obtain the maximal diagnostic yield, needle aspiration should be combined with the forceps biopsy.