In our previous study on fixed tissue blocks, we reported a high apoptotic
rate in patients with operated small cell lung carcinomas. In addition to t
umour cells, numerous apoptotic bodies could also be found within alveolar
macrophages within and close to tumour tissue. In order to test if such cel
ls could be found in sputum smears and if their presence could be utilized
as a marker in tumour diagnosis, we analyzed the occurrence of alveolar mac
rophages with apoptotic bodies (AMWABs) in a set of sputum smear and BAL sa
mples from patients with and without a pulmonary malignancy. An increased a
mount of AMWABs in the cytoplasm could be found in sputum and BAL samples f
rom patients with lung cancer. Interestingly, AMWABs could also be seen in
patients with a histologically confirmed pulmonary malignancy, but with no
detectable tumour cells in their sputum smear. Thus, the presence AMWABs in
sputum smears could serve as a more sensitive marker of pulmonary malignan
cy than the presence of malignant cells per se. This is the first report de
scribing apoptotic bodies in macrophages and the utility of their detection
in cancer diagnosis.