A 43-year-old man presented with fatigue after thalidomide treatment for plasma cell myeloma, diagnosed 3 years previously. A bone marrow aspiration was performed. The bone marrow clot section showed a peculiar rosettelike pattern, with a vasculocentric arrangement of malignant plasma cells (Figures 1 and 2). An aspirate smear showed numerous abnormal-appearing plasma cells (Figure 3). Most of the plasma cells had plasmablastic features with prominent, central nucleoli.
Rosettes come in many varieties—“true” (perhaps implying the existence of “untrue” rosettes), pseudo, vascular, and eponymous (Homer-Wright, Flexner-Winterstein)—as well as a variety of other names. They are useful in the diagnosis of certain neuroepithelial malignancies, ependymoma in particular, but they can also be seen in a variety of other neoplasms.
Rosettes have previously been reported in plasma cell myeloma.1 The relatively large amount of cytoplasm and perivascular crowding make these “faux” rosettes similar to ependymal rosettes. In this case, the previous treatment with thalidomide may be associated with the unusual appearance of the bone marrow. Thalidomide is associated with both antiangiogenic effects as well as antiproliferative effects on the multiple myeloma.2 In this case, the antiangiogenic action appeared focused primarily on the small vessels, with a sparing of the larger caliber vessels. The plasma cells crowd around the available blood supply of the larger vessels, giving them a rosettelike appearance.
References
Author notes
Reprints: Dennis P. O'Malley, MD, Indiana University School of Medicine, Department of Pathology and Laboratory Medicine, 702 Barnhill Dr, Riley 0969, Indianapolis, IN 46202 ([email protected])
