title: Identification of Primary Mediastinal Large B-cell Lymphoma at Nonmediastinal Sites by Gene Expression Profiling.
abstract: Mediastinal involvement is considered essential for the diagnosis of primary mediastinal large B-cell lymphoma (PMBL). However, we have observed cases of diffuse large B-cell lymphoma (DLBCL) with features of PMBL but without detectable mediastinal involvement. The goal was to assess our previously established gene expression profiling (GEP) signature for PMBL in classifying these cases. In a large series of DLBCL cases, we identified 24 cases with a GEP signature of PMBL, including 9 cases with a submission diagnosis of DLBCL consistent with PMBL (G-PMBL-P) and 15 cases with a submission diagnosis of DLBCL. The pathology reviewers agreed with the diagnosis in the 9 G-PMBL-P cases. Among the other 15 DLBCL cases, 11 were considered to be PMBL or DLBCL consistent with PMBL, 3 were considered to be DLBCL, and 1 case was a gray-zone lymphoma with features intermediate between DLBCL and classical Hodgkin lymphoma. All 9 G-PMBL-P and 9 of the 15 DLBCL cases (G-PMBL-M) had demonstrated mediastinal involvement at presentation. Interestingly, 6 of the 15 DLBCL cases (G-PMBL-NM) had no clinical or radiologic evidence of mediastinal involvement. The 3 subgroups of PMBL had otherwise similar clinical characteristics, and there were no significant differences in overall survival. Genetic alterations of CIITA and PDL1/2 were detected in 26% and 40% of cases, respectively, including 1 G-PMBL-NM case with gain of PDL1/2. In conclusion, PMBL can present as a nonmediastinal tumor without evidence of mediastinal involvement, and GEP offers a more precise diagnosis of PMBL.
authors.affiliation: *Department of Pathology and Microbiology ¶Department of Biostatistics, College of Public Health ##Department of Hematology/Oncology, University of Nebraska Medical Center, Omaha, NE †Metabolism Branch **Laboratory of Pathology, Center for Cancer Research, NCI, NIH, Bethesda, MD ∥Department of Pathology, City of Hope National Medical Center, Duarte, CA #Department of Pathology, University of Arizona, Tucson, AZ §§Department of Clinical Pathology, Oregon Health and Science University, Portland, OR ∥∥Department of Molecular Pathology and Laboratory Medicine, Cleveland Clinic, Cleveland, OH ‡Institute of Pathology, Comprehensive Cancer Center Mainfranken, University of Würzburg, Würzburg ¶¶Department of Clinical Pathology, Robert-Bosch-Krankenhaus, Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany §British Columbia Cancer Agency, Centre for Lymphoid Cancer, University of British Columbia, Vancouver, BC, Canada ††Hospital Clinic, IDIBAPS, University of Barcelona, Barcelona, Spain ‡‡Department of Pathology, The Norwegian Radium Hospital, University of Oslo, Oslo, Norway.
authors.forename: Ji
authors.initials: J
authors.lastname: Yuan
authors.forename: George
authors.initials: G
authors.lastname: Wright
authors.forename: Andreas
authors.initials: A
authors.lastname: Rosenwald
authors.forename: Christian
authors.initials: C
authors.lastname: Steidl
authors.forename: Randy D
authors.initials: RD
authors.lastname: Gascoyne
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Connors
authors.forename: Anja
authors.initials: A
authors.lastname: Mottok
authors.forename: Dennis D
authors.initials: DD
authors.lastname: Weisenburger
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Greiner
authors.forename: Kai
authors.initials: K
authors.lastname: Fu
authors.forename: Lynette
authors.initials: L
authors.lastname: Smith
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Rimsza
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Jaffe
authors.forename: Elias
authors.initials: E
authors.lastname: Campo
authors.forename: Antonio
authors.initials: A
authors.lastname: Martinez
authors.forename: Jan
authors.initials: J
authors.lastname: Delabie
authors.forename: Rita M
authors.initials: RM
authors.lastname: Braziel
authors.forename: James R
authors.initials: JR
authors.lastname: Cook
authors.forename: German
authors.initials: G
authors.lastname: Ott
authors.forename: Julie M
authors.initials: JM
authors.lastname: Vose
authors.forename: Louis M
authors.initials: LM
authors.lastname: Staudt
authors.forename: Wing C
authors.initials: WC
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060890:B7-H1 Antigen / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics*; D002899:Chromosomes, Human, Pair 9; D056915:DNA Copy Number Variations; D018572:Disease-Free Survival; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods; D015321:Gene Rearrangement; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D053208:Kaplan-Meier Estimate; D016403:Lymphoma, Large B-Cell, Diffuse / Q000737:chemistry / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D008297:Male; D008479:Mediastinal Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D008875:Middle Aged; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D011237:Predictive Value of Tests; D013997:Time Factors; D015534:Trans-Activators / Q000235:genetics; D014178:Translocation, Genetic; D055815:Young Adult
chemical_list: D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; C423236:CD274 protein, human; C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D015534:Trans-Activators