PMC4343282_01
PMC4343282_02
Pre-transplant bone marrow sampling. (A, B) H&E stained sections of the trephine biopsy at (A) x 10 and (B) x 100 oil. (C) Wright-Giemsa stained bone marrow particle crush at x 100 oil. (D) Flow cytometry of bone marrow aspirate samples. The majority of cells did not have increased forward scatter. The clone expressed uniform CD5, dim to absent CD20, CD23 and lambda light chain, but did not express CD79b.
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F1
Prior to transplant, her BM had a prominent diffuse, interstitial lymphoid infiltrate comprising 80-90% cellularity [Figure 1(A)]. The cells were small to intermediate in size with scant cytoplasm on hematoxylin and eosin (H&E) staining [Figure 1(B)], and had the usual characteristics of CLL/SLL, including scant cytoplasm and clumped chromatin, on Wright-Giemsa staining [Figure 1(C)].
Post-transplant bone marrow sampling documenting Richter transformation. (A) Neoplastic cells exhibited prominent nucleoli and vesicular chromatin. They expressed CD20 and PAX-5. Images were all captured with a x 100 oil objective. Main panel on left represents H&E stained core biopsy. Insert photo on left demonstrates large (3-4 times diameter of adjacent red cells) neoplastic lymphocytes, one with a prominent nucleolus, seen on Wright-Giemsa stained marrow smear. (B) The B-cell clone had increased forward scatter as determined by flow cytometry, but had the same expression of CD5, CD20, CD23 and lambda light chain as previously characterized (clonal population highlighted by red circle). Forward scatter plot demonstrates back-gated cells corresponding to the population within the red circle. (C) B-cell clonality assay by PCR (using Framework 2 and 3 primer sets) showed clonal rearrangement of the immunoglobulin heavy chain gene (IgH) in the bone marrow aspirate sample.
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F2
In comparison to prior biopsies, however, the cells were large, with vesicular chromatin and prominent nucleoli, expressing the B-cell markers CD20 and PAX-5 [Figure 2(A)]. Flow cytometry identified a 0.1% lambda-monotypic B-cell population that had CD5, dim CD20 and CD23 [Figure 2(B)]. The average forward scatter of this small population was increased [Figure 2(B)] compared to prior studies, indicating increased cell size. Molecular testing to look for B-cell receptor gene rearrangements demonstrated a clonal B-cell population [Figure 2(C)], and a major peak at 127 base pairs was clonotypic to that previously described in this patient's prior aspirates containing her CLL/SLL cells.