Metastatic neuroblastoma in bone marrow aspirate smears

The authors observed rosette formation and partially fibrillar, blue-grey, extracellular material in Wright-Giemsa-stained bone marrow aspirate smears in five preparations from three cases of neuroblastoma metastatic to bone marrow. These features are little publicized in the literature and textbooks. These findings in neuroblastoma metastatic to bone marrow should prove helpful in differentiating that entity from acute leukemia and from other metastatic small-cell neoplasms in bone marrow.