Histopathologic Features and Immunophenotype of 19 Primary Cutaneous Lymphomas

ABSTRACT

The diagnosis of primary cutaneous lymphoma is based on a combination of clinical, histological, immunophenotypic and genetic criteria. Nineteen cases of primary cutaneous lymphomas were studied for clinicopathologic, immunophenotypic, and genetic features. Seventeen (89%) cases were T cell origin and two cases (11%) were B cell origin. CD30-positive cutaneous lymphoproliferative disorder was the most frequent subtype, occupying 42% (8 cases) of the cases. CD8 was positive in 5 cases consisting of 3 cutaneous T cell lymphomas and 2 anaplastic large cell lymphomas. CD4 was positive in 2 cases of mycosis fungoides and 3 cases of lymphomatoid papulosis. Six (67%) of 9 cases of cutaneous T cell lymphoma were positive for TIA-1. Ten (83%) out of 12 cases showed clonal rearrangements of TCR gamma genes, however, one T/NK cell lymphoma and one anaplastic large cell lymphoma did not. EBV association was detected only in T/NK cell lymphomas among 10 cases examined. In conclusion, our study showed higher proportion of CD30-positive lymphoproliferative disorders and less frequent mycosis fungoides in Korea compared to the incidences in Western countries. Our immunostaining results suggested that mycosis fungoides and lymphomatoid papulosis are CD4-positive T cell origin, however, the remaining primary cutaneous T cell lymphoma is predominantly CD8-positive cytotoxic T cell origin.