Diffuse Large B-cell Lymphoma, NOS, Centroblastic



Diffuse Large B-cell Lymphoma, NOS, Centroblastic


Francisco Vega, MD, PhD





Key Facts


Terminology



  • Diffuse proliferation of large neoplastic B cells composed predominantly of centroblasts


  • Typical: Medium to large cells (10-14 µm) with fine chromatin, 2-3 small nucleoli often apposed to nuclear membrane, and scant basophilic cytoplasm


Clinical Issues



  • Most frequent morphologic variant of DLBCL


Microscopic Pathology



  • Diffuse growth pattern and predominantly composed of centroblasts


  • Sclerosis is frequent in extranodal sites


  • Usually express pan-B markers: CD20, CD22, CD79a, PAX5


  • Germinal center markers, CD10 and Bcl-6, expressed in variable proportion of cases


Ancillary Tests



  • t(14;18) is detected in almost 30% of cases; translocations involving 3q27 are also common


  • 2 major molecular groups of DLBCL



    • GC type


    • ABC type


    • Patients with DLBCL of GC type have better prognosis than those with ABC type


Top Differential Diagnoses



  • DLBCL, immunoblastic variant


  • DLBCL, anaplastic variant


  • Plasmablastic lymphoma


  • Follicular lymphoma (grade 3B)







Diffuse large B-cell lymphoma (DLBCL). Typical centroblasts image are large, noncleaved with vesicular chromatin and have membrane-bound nucleoli. Reactive small lymphocytes are also present image.






DLBCL composed of multilobated centroblasts image. The tumor cells are large, and some have deeply lobated nuclei.


TERMINOLOGY


Abbreviations



  • Diffuse large B-cell lymphoma (DLBCL), centroblastic


Synonyms



  • Centroblastic lymphoma


Definitions



  • Diffuse proliferation of large neoplastic B cells composed predominantly of centroblasts



    • Centroblasts



      • Typical: Medium to large cells (10-14 µm) with fine chromatin, 2-3 small nucleoli often closely apposed to nuclear membrane, and scant basophilic cytoplasm


      • Multilobated: Medium to large cells with lobated nuclei (> 3 lobes)


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Predominantly disease of adults and elderly but also occurs in children and young adults


    • Most frequent morphologic variant of DLBCL


Presentation



  • Enlarging mass in nodal or extranodal sites


  • Gastrointestinal tract is frequent extranodal site


  • Stage IV in at least 1/3 of cases


  • Bone marrow involvement occurs less frequently than in patients with low-grade B-cell lymphomas


  • Certain morphologic variants more prevalent at particular extranodal sites



    • Cells with multilobated nuclei in cases involving bone

Tags:
Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Diffuse Large B-cell Lymphoma, NOS, Centroblastic

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