Pseudo-Gaucher cell proliferation associated with myelodysplastic syndrome.

We report an extremely rare case of pseudo-Gaucher cell proliferation with myelodysplastic syndrome (MDS). A 77-year old Japanese man was referred to our hospital with splenomegaly and thrombocytopenia, and subsequent bone marrow aspiration revealed infiltrates of foamy vacuolated macrophages without any evidence of other morphologic abnormalities. A karyotype analysis showed the presence of 46,XY,del(20)(q11) in 20 of 20 examined bone marrow cells. We performed a splenectomy, and the resulting pathologic findings revealed massive infiltration of foamy vacuolated macrophages, which were morphologically compatible with Gaucher cells. The activities of beta-glucosidase and acid sphingomyelinase were within normal ranges; therefore, the foamy vacuolated macrophages were considered pseudo-Gaucher cells. A diagnosis of MDS, subclassified as refractory anemia, was then made according to World Health Organization classification guidelines. Pseudo-Gaucher cell proliferation and infiltration might therefore be observed in other patients presenting with MDS.