Primary pulmonary MALT lymphomas show frequent and heterogeneous cytogenetic abnormalities, including aneuploidy and translocations involving API2 and MALT1 and IGH and MALT1.
API2-MALT1 fusion and aneuploidy are common chromosomal abnormalities in MALT lymphoma. In studying their incidence and relationship in primary pulmonary MALT lymphomas, a translocation involving MALT1 and IGH was also identified. In all, 28 primary pulmonary MALT lymphomas were studied by fluorescence in situ hybridization using an API2-MALT1 probe and multiple centromeric probes, as well as IGH-BCL2, IGH-MALT1, and MALT1 breakapart probes in selected cases. Seven (25%) had API2-MALT1 fusion; all seven lacked aneuploidy except for two with trisomy 3 in a small clone. Three (11%) had IGH-MALT1 fusion; two also showed trisomy 3 and 12. A total of 11 (39%) had aneuploidy only, with trisomy 3 and 18 being the most common. Ectopic nuclear bcl-10 expression, which has been previously associated with API2-MALT1, was seen by immunohistochemistry in 86% of API2-MALT1 fusion-positive cases, one IGH-MALT1 fusion-positive case, two aneuploidy-only cases, and two normal cases. In primary pulmonary MALT lymphomas, cytogenetic abnormalities are common (75%) and heterogeneous, encompassing API2-MALT1 and IGH-MALT1, which are mutually exclusive, as well as aneuploidy, which may be present in the latter but is rare in the former. Ectopic nuclear bcl-10 expression is associated with API2-MALT1 but may also be seen in IGH-MALT1 fusion-positive, aneuploidy-only, and normal cases.
Divisions of Anatomic Pathology and Hematopathology, Mayo Clinic, Rochester, MN 55905, USA.
E D
ED
Remstein
P J
PJ
Kurtin
R R
RR
Einerson
S F
SF
Paternoster
G W
GW
Dewald
D048868:Adaptor Proteins, Signal Transducing; D000782:Aneuploidy; D017209:Apoptosis; D000074018:B-Cell CLL-Lymphoma 10 Protein; D002352:Carrier Proteins / Q000235:genetics; D020169:Caspases; D002503:Centromere / Q000235:genetics; D002881:Chromosomes, Human, Pair 12; D002887:Chromosomes, Human, Pair 18; D002893:Chromosomes, Human, Pair 3; D015342:DNA Probes; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D051034:Inhibitor of Apoptosis Proteins; D007621:Karyotyping; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics*; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D014178:Translocation, Genetic; D014314:Trisomy
D048868:Adaptor Proteins, Signal Transducing; D000074018:B-Cell CLL-Lymphoma 10 Protein; C118591:BCL10 protein, human; D002352:Carrier Proteins; D015342:DNA Probes; D007143:Immunoglobulin Heavy Chains; D051034:Inhibitor of Apoptosis Proteins; D009363:Neoplasm Proteins; D011506:Proteins; D020169:Caspases; C400109:MALT1 protein, human; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein