LABORATORY DATA
On evaluation, the patient had massive splenomegaly with pancytopenia. The WBC count was 1,500/mL, hemoglobin 9.1 g/dL and the platelet count was 27,000/mm3 with absolute neutropenia. His serum ANCA, HbsAg and RF were all negative. A bone marrow aspirate and core biopsy was performed as part of the workup (Figures 1, 2 and 3).

Figure 1: Bone Marrow Giemsa	Figure 2: Bone Marrow Giemsa	Figure 3: Bone marrow core biopsy

Peripheral blood smear normocytic anemia, anisopoikilocytosis, circulating nucleated red blood cells, severe thrombocytopenia and atypical cells.

ANCILLARY STUDIES
Flow cytometric analysis of the bone marrow aspirate shows a monoclonal population of B-lymphocytes (CD19, CD 20 positive) expressing CD45, CD19, CD20, bright CD22, bright CD11c, CD22 and negative for CD2, CD3, CD5 and CD10. Further testing using additional markers on flow cytometry allowed for exact typing of this bone marrow lesion.

Immunohistochemical stain CD20 is available for review (Figure 4).

Figure 4: CD20 on bone marrow core	Figure 5: Cytochemistry