Rare variant of DLBCL. These cases often have loss of CD45, CD20, and CD79a expression, which may cause significant difficulty in diagnosis. Less than 40 cases have been reported in the medical literature. The term ALK-positive plasmablastic B-cell lymphoma may be the best term to remember to correlate with the IHC profile.
Characteristic Immunophenotype
|
Marker
|
Comment
|
|
Negative
|
|
|
Negative
|
|
|
Negative
|
|
|
Weak/Negative
|
|
|
Positive
|
|
|
Positive (usually in a granular cytoplasmic pattern)
|
|
|
Positive
|
|
|
+/-
|
|
|
CD57
|
+/-
|
|
+/-
|
|
|
Negative. Rare cases have shown focal weak staining.
|
References
Parker, A., et. al. “Best Practice in Lymphoma Diagnosis and Reporting.” British Committee for Standards in Haematology, Royal College of Pathologists. April, 2010.
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.