gamma delta T-cell lymphoma of the skin: a clinical, microscopic, and molecular study

Only a few cases of primary gamma delta cutaneous T-cell lymphoma (CTCL) have been reported. We encountered 3 cases of this rare condition.

To characterize gamma delta CTCL by clinical, microscopic, and molecular methods and to investigate the role of Epstein-Barr virus (EBV) infection in its pathogenesis.

Patients were evaluated by clinical examination, and biopsy specimens of lesional skin were examined by light microscopy and immunohistochemistry. Polymerase chain reaction amplification for T-cell receptor gamma gene rearrangements and in situ hybridization for EBV were performed on 3 biopsy specimens.

National Institutes of Health, a tertiary referral center.

Individuals with a clinical and histologic diagnosis of primary gamma delta CTCL.

Clinical, light microscopic, and immunohistochemical features, and the presence of T-cell rearrangement and EBV RNA in biopsy specimens.

Patients exhibited multiple plaques, tumors, and/or subcutaneous nodules primarily distributed over the extremities. Individuals exhibited an aggressive clinical course with resistance to multiagent chemotherapy and radiation. Microscopic examination revealed epidermotropism in 2 cases, a dermal infiltrate in all 3 cases, and subcutaneous involvement in 1 case. Immunohistochemical studies showed the presence of CD3(+)TCR delta(+) in 3 patients, CD8(+)in 1, and CD4(+), CD20(+), CD56(+), and beta F1(+) in none. All 3 cases exhibited an activated cytotoxic T-cell phenotype positive for T-cell intracellular antigen 1, perforin, and granzyme B. A clonal T-cell receptor gamma chain gene rearrangement was detected in all 3 cases by polymerase chain reaction. In situ hybridization was negative for EBV sequences in all 3 cases.

gamma delta Cutaneous T-cell lymphomas are EBV-negative lymphomas that express a mature cytotoxic phenotype and have an aggressive clinical behavior. Arch Dermatol. 2000;136:1024-1032