Patterns of bone marrow involvement with small cell lung cancer.
The extent of tumor involvement, necrosis, reticulin, and megakaryocytosis were assessed in 25 patients with small cell lung cancer in their bone marrow at diagnosis. The pattern of marrow involvement was compared with clinical outcome and tolerance of therapy. Any marrow involvement, no matter how minor, is a poor prognostic factor. Neither more extensive involvement, nor greater marrow fibrosis significantly worsened the prognosis.