Primary nodal peripheral T-cell lymphomas: diagnosis and therapeutic considerations

Abstract

Nodal peripheral T-cell lymphomas are a rare group of neoplasms derived from post-thymic and activated T lymphocytes. A review of scientific articles listed in PubMed, Lilacs, and the Cochrane Library databases was performed using the term "peripheral T-cell lymphomas". According to the World Health Organization classification of hematopoietic tissue tumors, this group of neoplasms consists of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), anaplastic large cell lymphoma-anaplastic lymphoma kinase positive (ALCL-ALK(+)), and a provisional entity called anaplastic large cell lymphoma-anaplastic lymphoma kinase negative (ALCL-ALK(-)). Because the treatment and prognoses of these neoplasms involve different principles, it is essential to distinguish each one by its clinical, immunophenotypic, genetic, and molecular features. Except for anaplastic large cell lymphoma-anaplastic lymphoma kinase positive, which has no adverse international prognostic index, the prognosis of nodal peripheral T-cell lymphomas is worse than that of aggressive B-cell lymphomas. Chemotherapy based on anthracyclines provides poor outcomes because these neoplasms frequently have multidrug-resistant phenotypes. Based on this, the current tendency is to use intensified cyclophosphamide, doxorubicin, vincristine, prednisolone (CHOP) regimens with the addition of new drugs, and autologous hematopoietic stem cell transplantation. This paper describes the clinical features and diagnostic methods, and proposes a therapeutic algorithm for nodal peripheral T-cell lymphoma patients.

Keywords: Antineoplastic combined chemotherapy protocols; Diseases classification; Immunophenotyping; T-cell Lymphoma; World Health Organization.

Figure 1

Morphologic aspects of Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS). (A) Diffuse proliferation of atypical medium sized lymphoid cells. Note some intermingled eosinophils [hematoxylin and eosin (H&E)-stained section]. (B) Diffuse expression of CD3 by the neoplastic lymphoid cells. (C) These cells also express CD4. (D) CD7 antigen is only partially expressed by neoplastic T cells.

Figure 2

Morphologic aspects of angioimmunoblastic T-cell lymphoma. (A) Proliferation of small to medium sized lymphoid cells with mild atypia surrounding prominent high endothelial venules. Occasional large cells are observed, as well as some plasmocytes (H&E-stained section). (B) The majority of neoplastic lymphoid cells express membrane CD3. (C) Neoplastic lymphoid cells also express CD10. (D) CD20 antibody highlights the large B immunoblasts. (E) Follicular dendritic cell meshwork expansion surrounding high endothelial venules is evident with CD21 immunostain.

Figure 3

Morphologic aspects of anaplastic large cell lymphoma-anaplastic lymphoma kinase (ALK) positive. (A) Diffuse proliferation of large, highly atypical cells, with prominent pleomorphism (H&E-stained section). Some hallmark cells can be observed; they present large multilobulated ‘horseshoe-like’ nuclei. Neoplastic cells show diffuse expression of (B) CD30; (C) CD43; (D) epithelial membrane antigens and (E) ALK-1. In this case, ALK-1 positivity present exclusive cytoplasmic pattern.