Cutaneous T cell lymphoma with suppressor/cytotoxic (CD8) phenotype: identification of rapidly progressive and chronic subtypes.
We identified nine patients with cutaneous T cell lymphoma in whom the neoplastic cells expressed the CD8 (T8) suppressor T cell phenotype instead of the more common CD4 (T4) helper T cell phenotype. Five had rapidly progressive disease characterized by distinctive papulonodular skin lesions (four patients), involvement of palms or soles (four patients) or oral cavity (two patients), and poor response to standard topical therapy (four patients). Histologic examination showed extensive epidermotropism often associated with pagetoid features. Immunoperoxidase studies revealed a novel aberrant T cell phenotype characterized by lack of expression of CD4 and CD2 (T11) but positive staining for CD3 (T3) and CD7 (3A1). In contrast, the neoplastic cells from four patients with clinically more chronic CD8+ cutaneous T cell lymphoma, although also commonly epidermotropic, had a different aberrant T cell phenotype similar to that often seen in CD4+ mycosis fungoides; that is, there was lack of expression of CD7 but a positive reaction to staining for CD2. In two cases the tumor cells acquired the CD7 antigen or lost the CD2 antigen with progression of the disease. Two cases were analyzed with Southern blotting and both showed rearranged DNA bands that confirmed the presence of clonal populations of T cells. Our findings suggest the following: (1) CD8+ cutaneous T cell lymphoma can be rapidly progressive or chronic. (2) These two types cannot be reliably distinguished by histologic features. (3) Rapid progression was associated with a CD2-, CD7+ phenotype whereas chronicity was associated with a CD2+, CD7- phenotype.