CD20-positive primary nasal peripheral T-cell lymphoma: An analysis of one case and review of the literature.

CD20-positive T-cell lymphoma (TCL) is a very rare disease entity that is associated with the co-expressions of a range of T cell lineage makers, such as, CD2, CD3, CD5, or CD7, and CD20. The biological and clinical significance of CD20 antigen expressed in TCL has been unclear. Here, we are reporting an unusual case of CD20-positive primary nasal peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) in a 62-year-old female with both peripheral blood (PB) and bone marrow (BM) involvement. Flow cytometry (FC) analysis revealed CD20+ lymphoma cells in PB, BM, and lymph node (LN) and was consistent with pathological findings. FC immunophenotyping was proved of great diagnostic contribution.