title: FISH analysis for BCL-1 rearrangements and trisomy 12 helps the diagnosis of atypical B cell leukaemias.
abstract: We have investigated the diagnostic value of fluorescence in situ hybridisation (FISH) to detect t(11;14) and trisomy 12 in 53 cases with a B cell leukaemia difficult to classify on clinical and laboratory grounds. These cases were initially diagnosed by morphology and immunophenotype and in 33 of them, on tissue histology, as follows: chronic lymphocytic leukaemia (CLL), 20, 18 of them with atypical features; B cell prolymphocytic leukaemia (B-PLL), two; mantle-cell lymphoma (MCL), 15; splenic lymphoma with villous lymphocytes (SLVL), five; lymphoplasmacytic lymphoma, six; follicular lymphoma, one and, four cases remained unclassifiable. FISH demonstrated BCL-1 rearrangement in the circulating cells from 15 cases classified as: MCL (10), atypical CLL (three) and B-PLL (two). A definitive diagnosis of MCL was made on review of the spleen histology in one out of the three atypical CLL with BCL-1 rearrangement. Trisomy 12 was detected in eight cases which included four atypical CLL, one typical CLL, two MCL and one unspecified B cell lymphoma by histology and morphology. One of the MCL had both trisomy 12 and BCL-1 rearrangement and the other was CD5+, CD23+ and had a CLL score of 3, suggesting the latter diagnosis. Our findings demonstrate that FISH analysis is useful to clarify the nature of the disease in patients presenting with a B cell leukaemia in which the diagnosis is difficult by conventional methods. FISH established with certainty the diagnosis of MCL by showing BCL-1 rearrangement in over two-thirds of cases in which this was suspected, including blastoid forms, and confirmed the diagnosis of most cases of atypical CLL.
authors.affiliation: Academic Department of Haematology and Cytogenetics, The Royal Marsden Hospital and Institute of Cancer Research, Fulham Road, London SW3 6JJ, UK.
authors.forename: E
authors.initials: E
authors.lastname: Matutes
authors.forename: P
authors.initials: P
authors.lastname: Carrara
authors.forename: L
authors.initials: L
authors.lastname: Coignet
authors.forename: V
authors.initials: V
authors.lastname: Brito-Babapulle
authors.forename: N
authors.initials: N
authors.lastname: Villamor
authors.forename: A
authors.initials: A
authors.lastname: Wotherspoon
authors.forename: D
authors.initials: D
authors.lastname: Catovsky
mesh_terms: D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D019940:Genes, bcl-1 / Q000235:genetics*; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D015448:Leukemia, B-Cell / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D015463:Leukemia, Prolymphocytic / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D020522:Lymphoma, Mantle-Cell / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014178:Translocation, Genetic / Q000235:genetics*; D014314:Trisomy / Q000235:genetics*