Study on genetic aberrations of ocular mucosa-associated lymphoid tissue lymphomas occurring in southern China / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the genetic aberrations of ocular extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) type occurring in patients from southern China.</p><p><b>METHODS</b>Fifty seven paraffin-embedded ocular MALT lymphoma specimens from patients in southern China were studied by interphase fluorescence-in-situ hybridization (FISH) for genetic aberrations including t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/IgH-bcl-10, t(14;18) (q32;q21)/IgH-MALT1 and bcl-6/FOXP1 gene translocations.</p><p><b>RESULTS</b>Amongst the 57 cases studied, 9 cases (15.8%) showed chromosome translocations, including 4 cases (7.0%) of t(11;18)(q21;q21)/API2-MALT1, 1 case (1.8%) of t(14;18) (q32;q21)/IgH-MALT1, 1 case (1.8%) of bcl-6 gene-related chromosome translocation and 3 cases (5.3%) of IgH-unknown translocation partner. FISH revealed 17 cases (29.8%) with 3 copies of bcl-6 gene, 21 cases (36.8%) with 3 copies of MALT1 gene and 12 cases (21.1%) with 3 copies of both genes.</p><p><b>CONCLUSIONS</b>The MALT lymphoma-associated chromosome translocations t(11;18)(q21;q21)/API2-MALT1 and t(14;18) (q32;q21)/IgH-MALT1 are demonstrated in ocular MALT lymphomas of southern Chinese patients. The prevalence is significantly different from that reported in northern Chinese and northern American patients, indicating a geographic heterogeneity in the MALT lymphoma-associated genetic aberrations. The presence of 3 copies of bcl-6 and MALT1 genes is the commonest genetic abnormalities observed in ocular MALT lymphomas, suggesting a possible role in MALT lymphomagenesis.</p>

Primary ocular adnexal lymphoproliferative lesions: clinicopathologic features and genetic alterations / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate clinicopathological and genetic characteristics of primary ocular adnexal lymphoproliferative lesions.</p><p><b>METHODS</b>Clinical, morphological and immunohistochemical features of 37 archival cases of primary ocular adnexal lymphoproliferative lesions were studied including 5 cases of reactive lymphoid hyperplasia and 32 lymphomas retrospectively. Classification of the lymphomas were made according to the WHO classification of tumors of haematopoietic and lymphoid tissues. All cases were studied by interphase fluorescence in situ hybridization (FISH) using dual color break apart probes of IgH, MALT1, bcl-6, c-Myc, bcl-2, CCND1, bcl-10, and FOXP1 for detection of chromosomal aberrations involving IgH, MALT1, bcl-6, c-Myc, bcl-2, cyclinD1, bcl-10 and FOXP1 genes, respectively. FISH with IgH / bcl-2 dual color dual fusion probe was used for detection of t(14;18)(q32;q21)/IgH-bcl-2. CEP18 spectrum orange probe was used for detection of aneuploidy of the chromosome 18.</p><p><b>RESULTS</b>Among 32 cases of lymphomas, 28 cases (87.5%) were extranodal marginal zone B-cell lymphomas of mucosa associated lymphoid tissue (MALT lymphoma), 2 cases were follicular lymphoma (FL) and 2 cases diffuse large B cell lymphoma (DLBCL). Among the 28 cases of MALT lymphoma, chromosomal aberrations were found in 60.7% (17/28) by interphase FISH analysis. One case showed positive IgH break-apart signal with unknown partner. 16 cases showed three copies of different genes, of which, three copies of MALT1, bcl-6, and c-Myc were identified in 7 cases (25%), 12 cases (43%), and 2 cases (8%) of MALT lymphomas, respectively. In addition, 5 cases showed two genes including three copies of bcl-6 and MALT1 in 4 cases, and three copies of bcl-6 together with c-Myc in one case. Furthermore, all cases with three copies of MALT1 had trisomy 18. t(14;18)(q32;q21) was detected in both follicular lymphomas. Of the 2 DLBCL cases, one showed three copies of bcl-6 together with trisomy 18 and the other one showed three copies of bcl-6 together with IgH and c-Myc rearrangements. Chromosomal aberration was not found in all 5 cases of reactive lymphoid hyperplasia.</p><p><b>CONCLUSIONS</b>The most common entity of primary ocular adnexal lymphomas is MALT lymphoma and FISH is helpful for their differential diagnosis and classification. Trisomy 18 and three copies of bcl-6 are common chromosomal aberrations in primary ocular adnexal MALT lymphomas.</p>

Abnormal expression of bcl-10 protein in extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue lymphoma type / 中华病理学杂志

<p><b>OBJECTIVE</b>To evaluate the diagnostic role of nuclear expression of bcl-10 protein in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type.</p><p><b>METHODS</b>One hundred and forty cases of MALT lymphoma were collected from Cancer Hospital of Fudan University (including 38 cases from stomach, 35 cases from ocular adnexa, 16 cases from intestine, 15 cases from skin, 15 cases from salivary gland, 14 cases from lung, 3 cases from thyroid and 4 cases from other sites). Ten cases of reactive follicular hyperplasia of tonsil, 5 cases of reactive lymphoid hyperplasia of orbit and 143 cases of non-Hodgkin's lymphoma other than MALT lymphoma (including 20 cases of NK/T cell lymphoma, 20 cases of follicular lymphomas, 20 cases of anaplastic large cell lymphomas, 20 cases of nodal diffuse large cell B-cell lymphoma (DLBCL), 10 cases of gastric diffuse large B-cell lymphoma, 13 cases of nodal marginal zone B-cell lymphoma, 12 cases of mantle cell lymphoma, 11 cases of splenic marginal zone B-cell lymphoma, 6 cases of angioimmunoblastic T-cell lymphoma, 6 cases of peripheral T-cell lymphoma, not otherwise specified, 3 cases of small lymphocytic lymphoma, 1 case of lymphoplasmacytic lymphoma and 1 case of plasmacytoma were used as controls. Immunohistochemical study for bcl-10, as well as dual staining with CD20, was performed by EnVision method in paraffin sections.</p><p><b>RESULTS</b>In reactive follicular hyperplasia of tonsil, bcl-10 was moderately or strongly expressed in the cytoplasm of germinal center B cells, while the mantle cells were negative and the marginal zone cells and paracortical T cells showed weak staining. In the 5 cases of reactive lymphoid hyperplasia of orbit, 2 were bcl-10-negative and the remaining 3 expressed bcl-10 in the cytoplasm of germinal center B cells. As for non-MALT lymphomas, 3 gastric DLBCL showed nuclear expression. The remaining cases showed variable cytoplasmic staining. In some cases of lymphoma, bcl-10 was expressed in tumor cells but not in reactive lymphoid cells. On the other hand, 92.1% (129/140) of MALT lymphoma were bcl-10 positive. Among those cases, 54.3% (76/140) showed cytoplasmic positivity and 37.9% (53/140) showed nuclear positivity. The nuclear positivity rate of bcl-10 in different anatomic sites was different. The staining was most intense in MALT lymphoma of ocular adnexa. Dual staining with CD20 showed that the bcl-10-positive cells were also CD20-positive, though the number of bcl-10-positive cells were less than that of CD20-positive cells.</p><p><b>CONCLUSIONS</b>Bcl-10 expression in lymphoid hyperplasia is a universal phenomenon. Cytoplasmic expression of bcl-10 is seen in many different kinds of non-Hodgkin's lymphoma and reactive lymphoid conditions. In some cases of lymphoma, bcl-10 is expressed in tumor cells but not in reactive lymphoid cells, suggesting a possible role of abnormal bcl-10 expression in tumorgenesis. Nuclear expression of bcl-10 is seen mainly in MALT lymphoma, especially when occurring in ocular adnexa and lung. This is in contrast to loss of bcl-10 expression in residual germinal center cells.</p>