[Changes in bone marrow cellularity close to cancer metastases. Cyto-histologic study].

Before starting any therapy, we systematically studied by biopsy the bone marrow of 66 patients suffering from various cancers and suspect of marrow metastasis. Metastatic cells were thus found in 45 patients. Bone marrow composition was examined on histologic sections by granulometric method, while relative proportions and morphology of the various hematopoietic series were examined on cytologic prints. It then appeared that any important metastatic invasion goes together with deep alterations of the surrounding hematopoietic tissue, with frequent peri-metastatic collagenic fibrosis and hypoplasia of the various cell-lines; when metastatic growth is still moderate, hematopoietic tissue is, on the contrary, often hyperplastic, "irritative". These marrow alterations are not to be found far from the metastasis, and thus seem to be directly linked to the actual presence of cancerous cells.