Cutaneous graft-versus-host-like reaction in systemic T-cell lymphoma

We report a case of systemic T-cell lymphoma with cutaneous lesions showing histological features of a cutaneous graft-versus-host-like-reaction. Histology from liver, lymph node and bone marrow showed a malignant T-cell infiltrate. T-cell receptor gene rearrangement studies confirmed the diagnosis. A cutaneous graft-versus-host-like reaction has been reported with disseminated malignancy and one case has been reported with systemic lymphoma. Graft-versus-host disease normally occurs when lymphocytes from an immunocompetent donor are introduced into a histo-incompatible recipient who is incapable of rejecting them. In our patient a similar reaction may have occurred if the lymphoma was composed of cytotoxic cells or if a cell-mediated immune response against the malignant T-cells cross-reacted with epidermal keratinocytes. Alternatively the malignant T-cells could have been functionally active and induced a lichenoid reaction in the skin.