Comparison of rigid and flexible transbronchial needle aspiration in the staging of bronchogenic carcinoma

In staging bronchogenic carcinoma by transbronchial needle aspiration (TBNA ), rigid histology needles are generally preferred to flexible cytology nee dles owing to the widespread opinion that rigid needles have higher diagnos tic yield and less false-positive results. The objective of this study was to compare the efficacy and safety of the rigid and flexible TBNAs in stagi ng bronchogenic carcinoma to establish whether a flexible cytology needle m ethod can replace the rigid needle. A prospective study was conducted in 13 8 consecutive patients with extra- or endobronchial masses suggestive of br onchogenic carcinoma and amenable to surgical procedures. All 8 mm and larg er paratracheal, carinal, hilar and/or main bronchial lymph nodes determine d before bronchoscopy by computed tomography (CT) were sampled by successiv e 18-gauge rigid and 21-gauge flexible TBNAs in the same session. The anato mic landmarks were followed precisely during TBNAs, and a proper technique applied in sampling and specimen processing. Malignant lymph node involveme nt was specified in 97 (72%) cases of bronchogenic carcinoma by rigid, and in 89 (66%) by flexible TBNA. There were 4 (100%) benign cases (3 with tube rculosis and 1 with sarcoidosis) of 101 (73%) with positive rigid TBNAs (82 with histological and 19 with cytological specimens). TBNAs determined mal ignant lymph node involvement :in a total of 104 (78%) patients. Of 30 TBNA -negative patients, 14 were proven to have false-negative TBNAs by mediasti noscopy/mediastinotomy/minithoracotomy, and 16 to have true-negative TBNAs by thoracotomy. Thoracotomy confirmed true positivity in 52 rigid and 49 fl exible TBNAs, and false negativity in 4 rigid and 7 flexible TBNAs. Further staging was confirmed in these 7 cases. Four had proven false negative res ults by both methods. The presence of small cell carcinoma (21) or N-3 dise ase (27) presented a contraindication to thoracotomy in 48 TBNA-positive pa tients. Adequate-quality and malignant lymph node specimens were more frequ ently obtained by both techniques at advanced tumor and node stages. Howeve r, malignant lymph node invasion was significantly more frequent in rigid a nd flexible TBNA specimens only in the presence of advanced tumor status an d abnormal endoscopic appearance. The sensitivities of rigid and flexible T BNAs were 74 and 70%, respectively (p > 0.05), but both had a specificity o f 100%. Neither false-positive results nor serious complications other than hemorrhage of 30-100 mi (rigid: 5%, flexible: 2%)were encountered with eit her technique. These results indicate that in bronchogenic carcinoma, hilar and mediastinal lymph nodes can be staged by 21-gauge flexible TBNA (76%) as accurately as by 18-gauge rigid TBNA (79%) if a proper technique is appl ied and anatomic landmarks are followed precisely (p > 0.05).