Diagnosis of neuroblastoma by electron microscopy of bone marrow aspirates.

Three patients are reported in whom the diagnosis of neuroblastoma was made following electron microscopy of a bone marrow aspirate. The ultrastructure of neuroblastoma cells is distinctive, and they can be distinguished by electron microscopy from cells of the other tumors with which neuroblastoma is often confused by light microscopy. The rapidity with which the diagnosis can be obtained through use of this procedure argues for its adoption in any patient in whom the diagnosis is suspected and who has tumor cells in bone marrow. Early initiation of appropriate therapy is made possible, and elaborate diagnostic procedures may be avoided.