The spectrum of lymphoblastic, nodal and extranodal T-cell lymphomas: characteristic features and diagnostic dilemmas.
T-cell lymphomas represent a heterogeneous group of neoplasms that encompass considerable clinical, morphologic, and immunophenotypic variation. The diagnosis of T-cell lymphoma is challenging because of its relative rarity, the lack of an immunophenotypic marker of clonality, and significant morphologic overlap with infectious/inflammatory processes and neoplasms, including Hodgkin and other non-Hodgkin lymphomas, and even mesenchymal or epithelial lesions. In the current World Health Organization classification of hematopoietic tumors, all except 1 subtype (ie, T-lymphoblastic lymphoma) are recognized as mature neoplasms derived from postthymic T cells. In addition to T-lymphoblastic lymphoma, this review will focus on nodal and extranodal T-cell lymphomas and exclude T-cell lymphomas presenting primarily in the skin. Extranodal natural-killer-cell/T-cell lymphoma, nasal type, will also be discussed because the derivation of this lymphoma from natural killer and natural killer-like T cells shows morphologic and immunophenotypic features that overlap with other T-cell lymphomas. In this review, we discuss the salient clinicopathologic, immunophenotypic, and genetic features, as well as our approaches to the diagnosis of lymphoblastic, nodal, and extranodal T-cell lymphomas.
Department of Pathology, L235, Stanford University School of Medicine, Stanford, CA 94305-5324, USA. nsavage@stanford.edu
Natasha M
NM
Savage
Ryan C
RC
Johnson
Yasodha
Y
Natkunam
D002999:Clone Cells; D003001:Cloning, Molecular; D005260:Female; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D016411:Lymphoma, T-Cell, Peripheral / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D008297:Male; D009669:Nose Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D014178:Translocation, Genetic; D014944:World Health Organization