title: Indolent T- and NK-cell lymphoproliferative disorders of the gastrointestinal tract: a review and update.
abstract: Primary gastrointestinal (GI) T- and NK-cell lymphomas are usually aggressive neoplasms associated with high morbidity and mortality. Over the past two decades, however, cases of primary GI lymphoproliferative disorders (LPDs) or lymphomas of T- or NK-cell derivation with indolent behavior have been reported. These LPDs are rare and they can be challenging to diagnose as they share clinical and pathological features with both, inflammatory disorders and aggressive T- and NK-cell lymphomas. Primary, indolent clonal T-cell proliferations of the GI tract, which can be CD4+, CD8+ or CD4- CD8-, have been included as a provisional entity in the newly revised World Health Organization (WHO) classification of lymphoid neoplasms and designated 'indolent T-cell LPD of the GI tract'. It is currently unclear whether the indolent NK-cell LPDs represent reactive or neoplastic proliferations. In this review, we describe the clinical, morphologic, immunophenotypic and genetic features of indolent GI T- and NK-cell LPDs and provide guidance in differentiating them from other inflammatory and neoplastic diseases. We believe that greater awareness of these LPDs amongst physicians and the research community will lead to timely and accurate diagnoses, stimulate investigations into the pathogenetic mechanisms underlying different entities thereby enhancing our understanding of disease biology and enable the development of effective therapeutic regimens. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Pathology and Cell Biology, Division of Hematopathology, Columbia University Medical Center, New York, NY, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Matnani
authors.affiliation: Department of Pathology and Cell Biology, Division of Hematopathology, Columbia University Medical Center, New York, NY, USA.
authors.forename: Karthik A
authors.initials: KA
authors.lastname: Ganapathi
authors.affiliation: Department of Medicine, Division of Digestive and Liver diseases, Columbia University Medical Center, New York, NY, USA.
authors.forename: Suzanne K
authors.initials: SK
authors.lastname: Lewis
authors.affiliation: Department of Medicine, Division of Digestive and Liver diseases, Columbia University Medical Center, New York, NY, USA.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Green
authors.affiliation: Department of Pathology and Cell Biology, Division of Hematopathology, Columbia University Medical Center, New York, NY, USA.
authors.forename: Bachir
authors.initials: B
authors.lastname: Alobeid
authors.affiliation: Department of Pathology and Cell Biology, Division of Hematopathology, Columbia University Medical Center, New York, NY, USA.
authors.forename: Govind
authors.identifier: http://orcid.org/0000-0001-6250-048X
authors.initials: G
authors.lastname: Bhagat
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000166:cytology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D002454:Cell Differentiation; D049109:Cell Proliferation; D004724:Endoscopy; D005767:Gastrointestinal Diseases / Q000175:diagnosis* / Q000628:therapy; D041981:Gastrointestinal Tract / Q000503:physiopathology*; D006801:Humans; D016130:Immunophenotyping; D007249:Inflammation; D007694:Killer Cells, Natural / Q000166:cytology; D008223:Lymphoma / Q000175:diagnosis* / Q000628:therapy; D016399:Lymphoma, T-Cell / Q000175:diagnosis* / Q000628:therapy; D008232:Lymphoproliferative Disorders / Q000175:diagnosis* / Q000628:therapy
keywords: NK-cell; T-cell; gastrointestinal tract; indolent; lymphoma; lymphoproliferative disorder