Ferreira, Cristiane R.
Sahoo, Malaya K.
Lage, Luis A. P. C.
Zerbini, Maria C. N.
Total Authors: 9
 Stanford Univ, Dept Pathol, Sch Med, L235, 300 Pasteur Dr, Stanford, CA 94305 - USA
 Univ Sao Paulo, Dept Pathol, BR-01246 Sao Paulo, SP - Brazil
 Univ Sao Paulo, Dept Hematol, BR-01246 Sao Paulo, SP - Brazil
Total Affiliations: 3
Web of Science Citations:
Forkhead box P3 (FOXP3) is a specific marker for regulatory T-cells (Tregs). We report 6 cases of T-cell lymphomas with Treg phenotype based on diffuse positivity for FOXP3 in tumor cells. The patients showed a median age of 56 years with a male predominance. Sites of disease included lymph nodes (4), skin (2), subcutaneous tissue (1) and bone marrow (1). All cases showed monomorphic large cells, some with Hodgkin-like or anaplastic cells. All cases expressed pan T-cell markers and lacked cytotoxic markers; one case showed diffuse PD1 staining. Only one case harbored human T-lymphotrophic virus (HTLV)-1 DNA within tumor cells and was classified as adult T-cell leukemia/lymphoma (ATLL). Among 5 HTLV1-negative cases, 3 were classified as peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) and 2 fulfilled criteria for ALK-negative anaplastic large cell lymphoma (ALCL) with diffuse and strong CD30 positivity. We concluded that Treg phenotype may be rarely seen in HTLV1-negative cases, such as PTCL, NOS and ALK-negative ALCL. Our findings expand the spectrum of T-cell lymphomas with regulatory phenotype and suggest that consideration should be given to HTLV1 DNA testing in the appropriate clinical setting to rule out ATLL. (C) 2018 Elsevier Inc. All rights reserved. (AU)