Tumor cell colonies in bone marrow cultures from patients with small cell carcinoma of the lung.

Bone marrow specimens from 27 patients with small cell carcinoma of the lung (17 with limited and 10 with extensive disease) were plated in a culture system that supports the growth of multilineage haemopoietic progenitors CFU-GEMM. In five patients (three with extensive and two limited disease) atypical colonies could be observed that were not identifiable as haemopoietic colonies. Cytological staining and cytochemical examination as well as electronic micrographs suggest that these colonies are derived from metastatic carcinoma cells. The histological examination of marrow cells from three out of these five patients revealed no bone marrow involvement. Additional studies might provide further evidence whether bone marrow cultures are a useful probe in order to monitor bone marrow involvement in patients with small cell carcinoma of the lung.