Blastic NK-cell-like lymphoma with T-cell receptor gene rearrangement.

Blastic natural killer (NK) cell lymphoma is very rare but has been recently classified as a distinct entity in WHO classification. However, the classification remains controversial, and the clinicopathologic spectrum is not completely understood. We report a unique case of cutaneous CD4(+) CD56(+) malignancy with a typical clinical presentation and immunophenotype of blastic NK-cell lymphoma in a 15-year-old Guamanian girl. The skin was the only site involved by the lymphoma. Molecular study showed clonal T-cell receptor gamma gene rearrangement. The patient has been disease-free till now (more than 12 months following bone marrow transplant). This case may represent a tumor at an early stage of a common developmental pathway for T-cells and NK-cells.