TY - JOUR
T1 - MALT1 gene rearrangements and NF-κB activation involving p65 and p50 are absent or rare in primary MALT lymphomas of the breast
AU - Talwalkar, Sameer S.
AU - Valbuena, Jose R.
AU - Abruzzo, Lynne V.
AU - Admirand, Joan H.
AU - Konoplev, Sergej N.
AU - Bueso-Ramos, Carlos E.
AU - Medeiros, L. Jeffrey
N1 - Funding Information:
Correspondence: Dr LJ Medeiros, MD, Department of Hematopathology, Box 72, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. E-mail: ljmedeiros@mdanderson.org *Dr Talwalkar did this work as a visiting resident supported by a College of American Pathology Foundation Training in technology Award. His current address is Department of Pathology, University of Louisville, Louisville, Kentucky, USA. Received 20 December 2005; revised and accepted 5 July 2006; published online 18 August 2006
PY - 2006/11/4
Y1 - 2006/11/4
N2 - Mucosa associated lymphoid tissue (MALT) lymphomas arising in the breast are uncommon and few cases have been assessed for MALT lymphoma-associated translocations, BCL-10 expression, or NF-κB activation. In this study, we analyzed eight cases of primary breast MALT lymphoma. We also included 14 cases of primary breast diffuse large B-cell lymphoma since some of these may represent transformation of MALT lymphoma, known to occur at extra-mammary MALT sites. All cases were assessed for MALT1 gene rearrangements by fluorescence in situ hybridization (FISH). Using immunohistochemical methods, all cases were assessed for BCL-10, and subsets were assessed for NF-κB p65 and p50. None of the cases had MALT1 gene rearrangements by FISH. Of eight MALT lymphomas, BCL-10 was positive in seven (88%), with moderate nuclear and cytoplasmic staining in six, and a weak cytoplasmic staining in one. NF-κB p65 (n=8) and p50 (n=5) were negative or showed only cytoplasmic staining (ie inactivated) in all cases. Of 14 diffuse large B-cell lymphoma cases, BCL-10 was positive in 12 (87%), with weak-to-moderate cytoplasmic staining in 10, weak cytoplasmic and focally nuclear staining in one, and a moderate-to-strong nuclear and cytoplasmic staining in one. NF-κB p65 (n=11) showed cytoplasmic staining in all cases, whereas p50 (n=8) showed nuclear positivity (ie activated) in two (25%) cases. We conclude that MALT1 gene rearrangements are absent or rare in primary breast MALT lymphoma and diffuse large B-cell lymphoma. In MALT lymphomas, the moderate BCL-10 nuclear expression in six neoplasms is inconsistent with the FISH results, suggesting that BCL-10 immunostaining overestimates the frequency of MALT1 gene rearrangements. We also could not demonstrate NF-κB activation using nuclear staining for p65 and p50. In contrast, breast diffuse large B-cell lymphomas are heterogeneous. Weak cytoplasmic BCL-10 staining in most cases and evidence of NF-κB p50 activation in a subset differs from breast MALT lymphomas.
AB - Mucosa associated lymphoid tissue (MALT) lymphomas arising in the breast are uncommon and few cases have been assessed for MALT lymphoma-associated translocations, BCL-10 expression, or NF-κB activation. In this study, we analyzed eight cases of primary breast MALT lymphoma. We also included 14 cases of primary breast diffuse large B-cell lymphoma since some of these may represent transformation of MALT lymphoma, known to occur at extra-mammary MALT sites. All cases were assessed for MALT1 gene rearrangements by fluorescence in situ hybridization (FISH). Using immunohistochemical methods, all cases were assessed for BCL-10, and subsets were assessed for NF-κB p65 and p50. None of the cases had MALT1 gene rearrangements by FISH. Of eight MALT lymphomas, BCL-10 was positive in seven (88%), with moderate nuclear and cytoplasmic staining in six, and a weak cytoplasmic staining in one. NF-κB p65 (n=8) and p50 (n=5) were negative or showed only cytoplasmic staining (ie inactivated) in all cases. Of 14 diffuse large B-cell lymphoma cases, BCL-10 was positive in 12 (87%), with weak-to-moderate cytoplasmic staining in 10, weak cytoplasmic and focally nuclear staining in one, and a moderate-to-strong nuclear and cytoplasmic staining in one. NF-κB p65 (n=11) showed cytoplasmic staining in all cases, whereas p50 (n=8) showed nuclear positivity (ie activated) in two (25%) cases. We conclude that MALT1 gene rearrangements are absent or rare in primary breast MALT lymphoma and diffuse large B-cell lymphoma. In MALT lymphomas, the moderate BCL-10 nuclear expression in six neoplasms is inconsistent with the FISH results, suggesting that BCL-10 immunostaining overestimates the frequency of MALT1 gene rearrangements. We also could not demonstrate NF-κB activation using nuclear staining for p65 and p50. In contrast, breast diffuse large B-cell lymphomas are heterogeneous. Weak cytoplasmic BCL-10 staining in most cases and evidence of NF-κB p50 activation in a subset differs from breast MALT lymphomas.
KW - Breast
KW - DLBCL
KW - MALT-lymphoma
KW - MALT1 gene
KW - NF-κB p65
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U2 - 10.1038/modpathol.3800668
DO - 10.1038/modpathol.3800668
M3 - Article
C2 - 16917511
AN - SCOPUS:33750362214
SN - 0893-3952
VL - 19
SP - 1402
EP - 1408
JO - Modern Pathology
JF - Modern Pathology
IS - 11
ER -