Rare case of CD20-positive primary cutaneous T-cell lymphoma, NOS, with an aggressive clinical course

Primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS) is a group of T-cell lymphomas that does not fit the criteria of other primary cutaneous T-cell lymphomas (PCTCLs) defined by the WHO. The immunophenotype of the neoplastic T-cells can vary, with some cases showing aberrant expression of CD20. The diagnosis is exceedingly rare, and the prognosis is poor. 1