PMC3573821_01
Medium-sized cells with speckled chromatin and multiple small conspicuous nucleoli.
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F1
Pathology from fine needle aspiration showed medium-sized cells with speckled chromatin and multiple small conspicuous nucleoli (fig. 1).
Molecular cytogenetic analysis revealed a significant number of MYC/IgH fusion events.
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F2
Molecular cytogenetic analysis (fluorescence in situ hybridization) revealed a significant number of MYC/IgH fusion events (fig. 2).
Tumor cells are strongly positive for CD20, consistent with mature B-cell lineage.
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F3
Immunohistochemistry showed that the tumor cells were strongly positive for CD20, consistent with mature B-cell lineage (fig. 3).
Tumor cells show weak expression of BCL-2.
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F4
The tumor cells showed weak expression of BCL-2 (fig. 4).
Proliferation index is 100% by Mib-1 immunohistochemistry.
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F5
Ki-67 proliferation index was 100% by Mib-1 immunohistochemistry, consistent with the diagnosis of Burkitt's lymphoma (fig. 5).
EBV by in situ hybridization is negative in this tumor.
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F6
EBV by in situ hybridization was negative in this tumor, which is atypical of classical PTLD that are positive for EBV (fig. 6).