PCDLBCL, LT : Immunophenotype

Comments:
Immunophenotype of Primary Cutaneous Diffuse Large B-cell Lymphoma, Leg Type:

• Positive for B-cell markers such as CD20, CD79a, and PAX5
• Strongly express BCL2 (10% -ve), BCL6, IRF4/MUM1 (10% -ve), and FOXP1
• IgM is positive; 50% coexpress IgD
• CD10 is not expressed (+ve in <10%)
• Strong nuclear expression of MYC (75% of cases)
• MYC translocations are found only in 30% of cases
• Ki-67 proliferation index is 60-90%