title: Myeloperoxidase expression by histiocytes in Kikuchi's and Kikuchi-like lymphadenopathy.
abstract: Forty-five examples of Kikuchi's lymphadenitis (KL), 5 Kikuchi-like lupus erythematosus lymphadenopathies, 25 nonnecrotizing lymphadenitidies (5 toxoplasmic, 5 sarcoid-like, 6 dermatopathic, 4 suppurative, 3 tubercular, 2 with sinus histiocytosis), 4 examples of hyaline-vascular Castleman disease (CD), 2 plasmacytoid monocyte tumors (PM-Ts), and 61 accessory cell neoplasms were studied by a panel of antibodies, including the PG-M1 (against a macrophage-restricted CD68 epitope) and a polyclonal anti-myeloperoxidase (MPO). In KL and Kikuchi-like lupus erythematosus lymphadenopathies, 25 to 75% of CD68(+) histiocytes co-expressed MPO. This did not occur in nonnecrotizing lymphadenitidies and accessory cell neoplasms. MPO(+)/CD68(+) elements corresponded to nonphagocytosing mononuclear cells and some crescentic macrophages and phagocytosing histiocytes. Typical PMs were MPO(-)/CD68(+) in all cases, including CD and PM-T. Our observations suggest that in KL and KL-like lymphadenopathies: 1) MPO(+)/CD68(+) blood monocytes might be attracted into tissues because of the lack or paucity of granulocytes and the need of MPO for oxidative processes; 2) PMs are more likely to be involved in the cytotoxic immune reaction than in phagocytic phenomena; 3) the peculiar phenotype of the histiocytic component can be usefully used for the differentiation from malignant lymphoma and PM-T.
authors.affiliation: Pathology and Clinical Units, Institute of Hematology and Clinical Oncology L. & A. Seràgnoli, Bologna University, Bologna, Italy. pileri@almadns.unibo.it
authors.forename: S A
authors.initials: SA
authors.lastname: Pileri
authors.forename: F
authors.initials: F
authors.lastname: Facchetti
authors.forename: S
authors.initials: S
authors.lastname: Ascani
authors.forename: E
authors.initials: E
authors.lastname: Sabattini
authors.forename: S
authors.initials: S
authors.lastname: Poggi
authors.forename: M
authors.initials: M
authors.lastname: Piccioli
authors.forename: D
authors.initials: D
authors.lastname: Rondelli
authors.forename: F
authors.initials: F
authors.lastname: Vergoni
authors.forename: P L
authors.initials: PL
authors.lastname: Zinzani
authors.forename: P P
authors.initials: PP
authors.lastname: Piccaluga
authors.forename: B
authors.initials: B
authors.lastname: Falini
authors.forename: P G
authors.initials: PG
authors.lastname: Isaacson
mesh_terms: D000293:Adolescent; D000328:Adult; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D006644:Histiocytes / Q000378:metabolism* / Q000473:pathology; D020042:Histiocytic Necrotizing Lymphadenitis / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D008206:Lymphatic Diseases / Q000201:enzymology* / Q000473:pathology; D008221:Lymphoid Tissue / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000378:metabolism*; D012016:Reference Values
chemical_list: D009195:Peroxidase