PMC4204466_01
A. Bone marrow clot section shows immature cells with monoblastic morphology (right lower corner) intermixed with mature-appearing lymphocyte (left upper corner), H & E, X40. B and C. The mature-appearing lymphocytes co-express CD5 and CD19, consistent with chronic lymphocytic leukemia (CLL), B-CD19 stain, C-CD5 stain, X40. D. CD11c stain is positive in monoblastic population and negative in CLL population, CD11c stain, x40. E. There is a residual monoblastic population, but CLL population is not observed, H & E, x40. F. CLL population is relapsed (center), demarcated from monoblastic population, H & E, X40.
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PMC4204466_01_nihms635188f1.jpg
F1
A repeat bone marrow aspiration detected 20% monoblasts (Figure 1A, right lower corner) expressing CD11c antigen as assessed by immunohistochemistry (Figure 1D) and 24% monocytes. In addition, a large population of mature small lymphocytes (Figure 1A, left upper corner) co-expressing CD5 (Figure 1B) and CD19 (Figure 1C) antigens was noted. CLL cell aggregates were no longer detected by morphologic analysis (Figure 1E). Continuation of the same treatment regimen was recommended. However, a bone marrow aspiration and biopsy was compatible with relapsed AMML with 33% myelo-monoblasts and, in addition, relapsed CLL, interstitial pattern, comprising 5-10% of the total bone marrow cellularity (Figure 1F).