Multiple Hematopoietic-Cell Lineages in Multiple Myeloma

To the Editor: Using flow cytometry, Epstein and colleagues (March 8 issue)* found that myeloma cells expressed not only features characteristic of myeloma cells but also markers expressed on preB cells, megakaryocytes, myelomonocytes, and erythroid cells. The authors concluded that cells of multiple lineages are involved in multiple myeloma, and mentioned that these findings could imply the existence of a common neoplastic progenitor for all hematologic tumors. Another way to investigate the level at which the malignant process occurs in hematologic cancers is by determining the familial aggregation of hematologic cancers among patients with a specific disease — i.e., multiple…