title: Is ALK-gene rearrangement overlooked in primary gastrointestinal T-cell lymphomas? About two cases.
abstract: A 41-year-old male patient with a history of ankylosing spondylitis and Crohn disease, treated with immunomodulators and disease-modifying drugs, was diagnosed with a primary intestinal T-cell lymphoma that followed a 7.5-year-course. This transmural proliferation lacked cytological characteristics of anaplastic large cell lymphoma (ALCL), and was CD8-positive, and CD30- and anaplastic lymphoma kinase (ALK)-negative by immunohistochemistry (IHC). However, ALK-gene rearrangement (ALK-gr) was detected by fluorescence in situ hybridization (FISH) in both initial and persistent disease. The possibility of indolent T-cell lymphoproliferative disease of the gastrointestinal tract with atypical features (transmural involvement) related to ALK-gr was suggested. A previous case of aggressive 'enteropathy-associated ALCL' in the context of celiac disease was recently reported, which also lacked anaplastic morphology, and where CD30 and ALK expression was incidentally demonstrated by IHC, and ALK-gr subsequently confirmed by FISH. These two recent cases represent two distinct rare entities pertaining to the group of primary intestinal T-cell lymphomas, and they both show unexpected ALK-gr. This suggests that ALK-gr has been overlooked in the group of primary intestinal T-cell lymphomas. Performing IHC and FISH tests for ALK-gr in primary gastrointestinal T-cell lymphomas might be of importance, particularly with the advancement of targeted therapy that could impact treatment and prognosis.
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Wadad S
authors.initials: WS
authors.lastname: Mneimneh
authors.affiliation: Department of Internal Medicine, Indiana University School of Medicine, Indiana University Health Hospital, Indianapolis, Indiana, USA.
authors.forename: Shikhar Gautam
authors.initials: SG
authors.lastname: Vyas
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Oscar W
authors.initials: OW
authors.lastname: Cummings
authors.affiliation: Department of Pathology and Laboratory Medicine, Division of Hematopathology, Indianapolis, Indiana, USA.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Czader
mesh_terms: D000328:Adult; D000368:Aged; D000077548:Anaplastic Lymphoma Kinase; D003937:Diagnosis, Differential; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007414:Intestinal Neoplasms / Q000235:genetics* / Q000473:pathology; D017730:Ki-1 Antigen / Q000378:metabolism*; D016399:Lymphoma, T-Cell / Q000235:genetics* / Q000473:pathology; D008297:Male; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D014178:Translocation, Genetic
chemical_list: D017730:Ki-1 Antigen; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases
keywords: anaplastic large T-cell lymphoma; anaplastic lymphoma kinase; enteropathy associated T-cell lymphoma; indolent T-cell lymphoproliferative disorder of the GI tract; intestinal T-cell lymphoma