Phenotypic heterogeneity of lymphoma of the skin.

We studied surface markers present in 56 cases of lymphoma of the skin by immunohistochemical staining, using the ABC (avidin-biotin-peroxidase complex) and PAP (peroxidase-antiperoxidase complex) methods. Of these cases, 49 were T-cell lymphoma and 7 were B-cell lymphoma. Ten of the 49 cases of T-cell lymphoma were adult T-cell leukemia/lymphoma (ATL). Twenty-five of 31 cases of T-cell lymphoma except ATL analyzed by the ABC method showed a helper/inducer phenotype (Leu2a-,Leu3a+), two cases showed a suppressor/cytotoxic phenotype (Leu2a+, Leu3a-), one case showed Leu2a+Leu3a+, one case showed an inducer phenotype (Leu2a-, Leu3a+, Leu9+), and one case showed OKT11+, Leu2a-, Leu3a-, Leu1-, Leu9+, CD25+, Leu10+, CD30+. One CD8+ lymphoma was Pagetoid reticulosis, and a CD4+, CD8+ lymphoma was lymphomatoid papulosis with erythematous plaque. Cutaneous T-cell lymphoma (CTCL), previously described by Edelson et al., is defined as a helper T-cell lymphoma with marked affinity for the skin. In our study, 5 cases of T-cell lymphoma of the skin were not CTCL as described by Edelson et al. These results show that T-cell lymphoma of the skin is heterogeneous in nature. In other words, CTCL is one type but represents a major proportion of T-cell lymphomas of the skin.