title: Diagnostic cues for natural killer cell lymphoma: primary nodal presentation and the role of in situ hybridisation for Epstein-Barr virus encoded early small RNA in detecting occult bone marrow involvement.
abstract: Natural killer (NK) cell lymphomas are rare, and atypical features might lead to diagnostic pitfalls. This report describes an unusual patient in whom lymphoma occurred initially as isolated lymph node involvement, an exceptional presentation of an almost exclusively extranodal disease. Furthermore, during the terminal haemophagocytosis in the bone marrow, lymphoma cells lost the expression of the NK cell marker, CD56, making the histopathological diagnosis of bone marrow involvement difficult. This was resolved by in situ hybridisation for Epstein-Barr virus encoded small RNA, which detected occult bone marrow infiltration.
authors.affiliation: University Department of Medicine, Queen Mary Hospital, Pokfulam Road, Hong Kong, China.
authors.forename: C-S
authors.initials: CS
authors.lastname: Chim
authors.forename: E S K
authors.initials: ES
authors.lastname: Ma
authors.forename: F
authors.initials: F
authors.lastname: Loong
authors.forename: Y-L
authors.initials: YL
authors.lastname: Kwong
mesh_terms: D019046:Bone Marrow Neoplasms / Q000276:immunology / Q000473:pathology*; D019002:CD56 Antigen / Q000032:analysis; D020031:Epstein-Barr Virus Infections / Q000276:immunology / Q000473:pathology; D017809:Fatal Outcome; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D007694:Killer Cells, Natural / Q000276:immunology / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology; D008223:Lymphoma / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000032:analysis
chemical_list: D019002:CD56 Antigen; D012367:RNA, Viral