A primary cutaneous non-T, non-B CD4(+), CD56(+) lymphoma

Background: Cutaneous lymphomas are heterogeneous clonal lymphoproliferative disorders originating from B or T lymphocytes. Observation: We describe a patient with a unique primary cutaneous lymphoma characterized by a bruise-like aspect of the skin lesions, a CD4(+), CD43(+), CD56(+), CD2(-), CD3(-), CD8(-), T-cell receptor-negative phenotype of the medium-sized to large lymphoid tumor cells and an undetermined genotype (T-cell receptor beta and immunoglobulin heavy chain in germline configuration, no clonal T-cell receptor gamma population as detected after analysis with polymerase chain reaction combined with denaturing gradient gel electrophoresis) and fast relapse after radiotherapy. Conclusions: This non-B, non-T cutaneous lymphoma cannot be classified by any current lymphoma classification. It seems to represent a new disease entity with peculiar clinical, histologic, and molecular features.