Small bronchogenic carcinomas presenting as solitary pulmonary nodules. Bioptic approach guided by CT-positive bronchus sign.

To evaluate the utility of the CT bronchus sign in making a choice between transbronchial biopsy (TBB) and transthoracic needle aspiration (TTNA) as the first diagnostic procedure in a patient with a solitary pulmonary nodule (SPN), we reviewed the results of TBB and TTNA in 26 patients who had a bronchogenic carcinoma less than 3 cm, studied with thin-section CT. The patients were divided into two groups. Group 1 included ten cases with a third- to fifth-order bronchus sign. Group 2 included two cases with a sixth-order bronchus sign and 14 cases with absence of a bronchus sign. TBB was performed in all the patients; conversely, TTNA was carried out in 22 patients. In group 1, TBB gave a diagnostic yield in eight (80 percent) of ten patients, while TTNA was positive in three (42 percent) of seven patients (p > 0.05). Conversely, in group 2, results of TBB were normal in all the patients, while TTNA gave a diagnosis in 10 (66 percent) of 15 patients (p < 0.05). We think that TBB should be considered the method of choice in diagnosing SPNs associated with a third- to fifth-order bronchus sign; conversely, TTNA is more useful than TBB in diagnosing SPNs in the presence of a more peripheral bronchus sign or with the absence of a bronchus sign. In conclusion, we suggest routine evaluation with thin-section CT of each SPN to optimize diagnostic management.