title: The utility of IgM, CD21, HGAL and LMO2 in the diagnosis of pediatric follicular lymphoma.
abstract: Pediatric follicular lymphoma (pFL) is a rare neoplasm with features differing from follicular lymphoma arising in adults. Here, we describe a rare case of pFL that showed morphologic features partially overlapping with progressive transformation of germinal centers and reactive follicular hyperplasia. As typical of pFL, neoplastic B cells within follicles did not express B-cell leukemia/lymphoma 2 (BCL2). However, this case showed additional distinctive abnormal findings, which contributed to the diagnosis: (1) diffuse and uniform staining of immunoglobulin M (IgM) on cells within and outside of follicles, (2) abnormally dim expression of CD21 on follicular dendritic cells, and (3) expression of human germinal center-associated lymphoma (HGAL) and LIM domain only 2 (LMO2) on B cells in interfollicular and follicular areas. This case demonstrates the utility of these abnormal features, which can be seen in adult- or usual-type follicular lymphoma, in the diagnosis of pFL. Further studies are necessary to evaluate the significance of these findings in other cases of pFL.
authors.affiliation: Department of Pathology, University of Kansas Medical Center, Kansas, KS 66160.
authors.forename: Tejashree
authors.initials: T
authors.lastname: Karnik
authors.affiliation: Department of Pathology, Stanford University, Stanford, CA 94305.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Ozawa
authors.affiliation: Department of Pathology, Stanford University, Stanford, CA 94305.
authors.forename: Martina
authors.initials: M
authors.lastname: Lefterova
authors.affiliation: Department of Pediatrics, Stanford University, Stanford, CA 94305.
authors.forename: Sandra
authors.initials: S
authors.lastname: Luna-Fineman
authors.affiliation: Department of Pediatrics, Stanford University, Stanford, CA 94305.
authors.forename: Elysia
authors.initials: E
authors.lastname: Alvarez
authors.affiliation: Department of Pediatrics, Stanford University, Stanford, CA 94305.
authors.forename: Michael
authors.initials: M
authors.lastname: Link
authors.affiliation: Department of Pathology, Stanford University, Stanford, CA 94305.
authors.forename: James L
authors.initials: JL
authors.lastname: Zehnder
authors.affiliation: Department of Pathology, Stanford University, Stanford, CA 94305.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Arber
authors.affiliation: Department of Pathology, Stanford University, Stanford, CA 94305. Electronic address: rohgami@stanford.edu.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Ohgami
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D001402:B-Lymphocytes / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002648:Child; D018858:Germinal Center / Q000473:pathology; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins / Q000378:metabolism*; D008224:Lymphoma, Follicular / Q000175:diagnosis* / Q000378:metabolism*; D008297:Male; D008840:Microfilament Proteins; D009363:Neoplasm Proteins / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D017464:Receptors, Complement 3d / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; C476824:GCSAM protein, human; D007075:Immunoglobulin M; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; C085117:LMO2 protein, human; D008840:Microfilament Proteins; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D017464:Receptors, Complement 3d
keywords: Adult follicular lymphoma; HGAL; IgM; LMO2; Pediatric follicular lymphoma