Non lymphoblastic T cell lymphomas with prevalent skin involvement different from mycosis fungoides or Sézary's syndrome. A retrospective study of 6 cases in Europe.

A retrospective study of 23 cases of nonlymphoblastic T cell lymphomas with no features of either mycosis fungoides (MF) or Sézary syndrome (SS) was carried out. 6 patients exhibited cutaneous (or mucous) lesions and are presented herein. There was no detectable visceral or node involvement except in 1 patient. 3 cases were immunologically proven to be of peripheral T cell origin. Except T cell lymphomas in Japan and in the Caribbean area, the frequency of prevalent skin involvement is reportedly very low in non-MF/SS non lymphoblastic T cell lymphomas. However, it is likely that this frequency has been underestimated in Western countries. The histologic features of our cases run the heterogeneous spectrum of recently described node-based forms of peripheral T cell lymphomas: 'angioimmunoblastic lymphadenopathy with dysproteinemia'-like lymphoma, large T cell lymphoma, multilobulated cell lymphoma, T zone lymphoma. The histologic pattern of skin infiltration was different from that of MF/SS. One case was initially suggestive of a pseudolymphoma and had a prolonged evolution but the other patients suffered from rapid extracutaneous involvement and fatal evolution with resistance to treatment. Cutaneous plasmacytomas were seen in 1 case. Hence, certain cutaneous T cell lymphomas exhibit histologic, immunological and developmental features similar to those of node-based peripheral T cell lymphomas but different from those of MF/SS.