γδ T-cell neoplasms: A clinicopathological study of 11 cases

Background: The majority of T-cell neoplasms express T-cell antigen receptor (TCR) αβ on their cell surface, and a few cases show the TCR γδ phenotype. Recently, a variety of γδ T-cell neoplasm was recognized; however, its clinicopathological features have not been extensively analyzed. Here we report the results of a clinicopathological study of 11 cases of γδ T-cell neoplasm. Patients and methods: During the 11-year period from 1989 to 1999, 104 patients with T-cell neoplasms were examined by flow cytometric analysis and/or immunohistochemical analysis. Tumor cells from all 104 patients expressed one or more of the T-cell antigens-CD2, CD3, CD5 and CD7. Forty-nine of the 104 cases of T-cell neoplasms were examined immunophenotypically for TCR αβ/γδ subsets. Results: Expression of TCR γδ on tumor cells was found in five (33%) of 15 patients with precursor T-cell lymphoblastic leukemia/lymphoma, one (25%) of four with T-cell granular lymphocytic leukemia and five (26%) of 19 with peripheral T-cell lymphoma (PTCL), whereas no expression was found in 11 patients with adult T-cell leukemia-lymphoma. Primary sites of the five patients with γδ PTCL were as follows: lymph node, three; skin, one and liver, tonsil and skin, one. The courses of the three patients with γδ PTCL of nodal onset were very short (3, 5 and 9 months, respectively), and they were all resistant to combination chemotherapies. Conclusions: Although γδ T-cell neoplasm constitutes a heterogeneous population, it is important to examine the expression of TCR with the view to identifying possible poor prognostic subgroups, such as primary nodal γδ T-cell lymphoma.