Primary cutaneous marginal zone lymphoma (MZL) is a common B-cell lymphoma of skin and is characterized by an infiltrate of neoplastic marginal zone B cells typically within the marginal zones of reactive lymphoid follicles and the interfollicular region. However, in our experience, many cases have underemphasized features such as marked plasmacytic differentiation and/or a prominent T-cell component, which may obscure the neoplastic B cells and lead to misdiagnosis. We wanted to draw attention to these features and have studied 15 cases of MZL with marked plasmacytic differentiation, 10 of which had numerous T cells, some with cytologic atypia, and few B cells in the interfollicular region. Plasma cells were monotypic in all cases by in situ hybridization. By polymerase chain reaction, 6 of 8 T cell-rich cases had an IGH gene rearrangement, and none were clonal for T-cell receptor gene. We discuss the terminology, morphologic features, molecular profile, behavior, and differential diagnosis of cutaneous MZL.
[Show abstract][Hide abstract] ABSTRACT: IntroductionIn this era of precision medicine, targets for new drugs are to be found across the range of tumors. Tissue microarrays are often used for that purpose, and for instance, Fernandez et al.  stained 395 lymphomas for Bruton’s tyrosine kinase protein expression showing that many B cell lymphomas, some T cell lymphomas, 14/16 nodular lymphocyte predominant, and 6/27 classic Hodgkin lymphoma (cHL) were positive. However, expression of a protein does not fully correlate with therapy response, so such studies can only serve as an initial screen. A next step is to study the effect of a drug in cell lines, like the work of Choudhary et al. , who investigated the effect of a Bcl-2 inhibitor on B cell lymphoma cell lines and also the acquired resistance after treatment. They showed that the B cell lymphoma cells upon treatment with Bcl-2 inhibition increased their expression of MCL-1 and Bcl-x, which resulted in resistance that could be overcome by inhibition of these factors. T ...
Journal of Hematopathology 06/2010; 3(1):47-58. DOI:10.1007/s12308-010-0060-x
[Show abstract][Hide abstract] ABSTRACT: Cutaneous marginal zone lymphomas (CMZL) were segregated in the WHO/EORTC consensus classification but grouped with other MALT lymphomas in the subsequent WHO classification. It has been suggested, however, that CMZL have distinctive features and might include 2 subsets. To address these issues, the clinicopathologic, phenotypic and, when possible, genotypic features of 29 CMZL with plasmacytic differentiation were assessed. The monotypic plasma cells had class-switched heavy chain expression in 22 cases, technically inadequate staining in 1 case (included with class-switched cases for analysis) and 6 were IgM. The class-switched cases had a predominance of T cells in 22 out of 23 cases with a CD4:CD8>1 in 15 out of 16 cases, usually showed nodules and scattered small B cells often with IgD apparently nonneoplastic follicles, lacked CXCR3 B-cell expression, never showed a totally diffuse growth pattern, often had prominent mast cells, and lacked known extracutaneous involvement. The IgM cases showed a predominance of B cells in 5 out of 6 (P=0.0003), a diffuse proliferation of CD20 B cells in all (P<0.0001), CXCR3+ B cells in 2 out of 5 (P<0.04), and extracutaneous disease in 3 out of 6 (P<0.008). CD21 usually disrupted follicular dendritic meshworks were seen in 9 out of 12 class-switched and 5 out of 5 IgM cases. CD123 plasmacytoid dendritic cells, PD1+ T follicular helper cells, CD25 or FOXP3+ regulatory T cells, and TIA1/granzyme B cytotoxic cells were never numerous. Only 1 out of 14 tested cases showed a low-level clonal/oligoclonal T cell receptor γ gene rearrangement. These findings support the presence of 2 types of cutaneous MALT lymphomas with the class-switched cases being the most distinctive but still sharing significant features with MALT lymphomas from other sites, specifically an extranodal extramedullary CD5-, CD10- indolent small B cell lymphoma with plasmacytic differentiation, frequent benign follicular structures, and not fulfilling the criteria for any other well-defined lymphoma.
The American journal of surgical pathology 12/2010; 34(12):1830-41. DOI:10.1097/PAS.0b013e3181f72835 · 5.15 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.