Sputum cytology for the detection of pulmonary metastases from colorectal carcinoma.

Twenty-two patients with pulmonary metastases from adenocarcinoma of the colon and rectum had sputum samples examined for cytology. All patients had lesions demonstrated on chest roentgenography and eight patients also underwent bronchoscopy. Three or more sputum samples were examined for eight patients, two samples for seven patients, and seven patients had one sample only examined. In five of 22 patients, the sputum samples were reported to be unsatisfactory for cytodiagnosis. Of the remaining 17, nine patients had at least one positive result for metastatic adenocarcinoma and in two additional cases the sample showed atypical cells. The result was therefore positive or atypical in 11 of 17 patients (65 percent). The positive cytology rate reported (79 percent for multiple pulmonary metastases) represents an improvement compared with previously published work. In this study 14 patients had either one or two samples collected for cytology and it is likely that the positivity rate would have been higher if three samples had been collected.