Bone-marrow examination in the staging of small-cell anaplastic carcinoma of the lung with special reference to subtyping. An evaluation of 203 consecutive patients.

Histologic examination of bone-marrow from the posterior iliac crest was routinely done as a pretreatment staging procedure in 203 consecutive patients with small-cell anaplastic carcinoma of the lung. Subtyping of the patients according to the WHO classification included 27.8% with "fusiform" cell type (WHO II,1), 28.3% with "polygonal" cell type (WHO II,2), 42.8% with "lymphocyte-like" cell type (WHO II,3), and 1.1% with mixed types (WHO II,4). Bone-marrow involvement was found in 17.2%. No significant difference was observed among the histological subtypes with regard to bone-marrow involvement. A comparison of bone-marrow biopsy and aspiration in patients investigated with both procedures showed that aspiration alone was diagnostic in nine of 24 (38%) positive patients as compared with two of 24 (8%) with biopsy alone, while in the remaining 13 patients (54%) both procedures were positive. Of the 35 patients with positive bone-marrow examination, 77% had no other evidence of distant metastatic disease if liver metastases identified by peritoneoscopy and liver biopsy are excluded as a staging procedure. With the exception of thrombocytopenia which was observed in six patients, with bone-marrow metastases, hematological findings were of little value in detecting bone-marrow involvement.