Figure 1.
Typical morphology of bone marrow or lymph node involvement in BL. (A) Typical morphology of bone marrow with involvement by BL. Characteristic immunophenotype illustrated by immunohistochemistry: CD20+, CD10+, Ki67+ (100%), TdT– (terminal deoxynucleotidyl transferase), and CD34–. Classic translocation involving c-myc and immunoglobulin heavy chain genes is illustrated by fluorescence in situ hybridization (FISH) analysis with probes for 14q32 (immunoglobulin heavy chain [IgH]), green; 8q24 (MYC), red; and chromosome 8 centromere probe, aqua. Fusion product t(8;14)(q24:q32) in yellow (indicated by arrows). (B) Typical morphology of lymph node with involvement by BL. Characteristic immunophenotype illustrated by immunohistochemistry: CD20+, CD10+, Ki67+ (100%), TdT–, and CD34–. Classic translocation involving c-myc and immunoglobulin heavy chain genes is illustrated by FISH analysis with probes for 14q32 (IgH), green; 8q24 (MYC), red; and chromosome 8 centromere probe, aqua. Fusion product t(8;14)(q24;q32) in yellow (indicated by arrows). The large images of bone marrow and lymph node involvement in panels A and B were obtained using an Olympus BX50 microscope (Olympus, Tokyo, Japan) equipped with an Olympus UPlanF1 40 ×/0.75 objective lens (H&E images of bone marrow and lymph node), or an Olympus UPlanF1 20 ×/0.50 objective lens (CD20, CD10, Ki67, TdT, and CD34 immunohistochemistry stains). Photography was performed with an MTI 3CCD digital camera (DAGE-MTI, Michigan City, IN), PAXit 2.0 acquisition software (MIS, Franklin Park, IL), and Adobe Photoshop 7.0 imaging software (Adobe, San Jose, CA). The immunohistochemical stains were obtained using DAKO autostainer universal staining system (DAKOCytomation, Carpinteria, CA) and the following antibodies: CD10 clone 56C6 (Novocastra, Newcastle upon Tyne, United Kingdom), CD20 clone L26 (DAKOCytomation, Glostrup, Denmark), CD34 clone QBEND10 (Immunotech, Marseilles, France), Ki67 clone MIB-1 (DAKOCytomation), and TdT clone A3524 (DAKOCytomation). The FISH insert images were acquired using the Vysis IgH/MYC/CEP-8 Dual Fusion DNA probe (Vysis/Abbott, Downers Grove, IL), a Zeiss Axioskop microscope equipped with a Zeiss PlanApo 100 × oil immersion objective lens and dual band pass filter (Carl Zeiss, Thornwood, NY), and Applied Spectral Imaging (Vista, CA) digital camera and software version 3.0.