Primary breast diffuse large B-cell lymphoma shows an activated B-cell–like phenotype

Mutational profile of primary breast diffuse large B-cell lymphoma

Primary breast lymphoma is a rare form of extra-nodal lymphoid neoplasm. The most common histological type is the diffuse large B-cell lymphoma, which represents 60–80% of all the cases. Our study analyzes the mutational profile of the primary lymphoma of the breast through targeted massive sequencing with a panel of 38 genes in a group of 17 patients with primary breast diffuse large B-cell lymphoma. Seventy-point-five percent of the patients presented with stage IE and 29.5% with stage IIE. 44% of the cases correspond to lymphomas with germinal center phenotype and 33.3% to activated B-cell. The genes with a higher mutational frequency include PIM1 (in 50% of the analyzed samples), MYD88 (39%), CD79B, PRDM1 and CARD11 (17%), KMT2D, TNFIAP3 and CREBBP (11%). The profile of mutant genes involves mostly the NFκB signaling pathway. The high frequency of mutations in PIM1 compared with other lymphomas may have implications in the clinical presentation and evolution of this type of lymphoma.

Hematolymphoid lesions of the breast

Hematolymphoid malignancies of the breast are most commonly neoplasms of mature B-lymphocytes, and may arise as a primary disease or by secondary involvement of a systemic disease. Primary breast lymphomas (PBL) account for 0.04-0.5% of breast malignancies, less than 1% of all non-Hodgkin's lymphomas (NHL), and less than 5% of extranodal lymphomas (Lakhani et al., 2012; Swerdlow et al., 2008; Joks et al., 2011; Barişta et al., 2000; Giardini et al., 1992; Brogi and Harris, 1999; Topalovski et al., 1999).^1-7 Secondary breast lymphomas (SBL) are also rare, with an estimated annual incidence of 0.07% (Domchek et al., 2002; Talwalkar et al., 2008).^8,9 Recognition of breast lesions as hematolymphoid is critical to distinguish them from other entities that can occur in the breast.

Primary central nervous system diffuse large B-cell lymphoma shows an activated B-cell-like phenotype with co-expression of C-MYC, BCL-2, and BCL-6

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma, whose main prognostic factor is closely related to germinal center B-cell-like subtype (GCB- DLBCL) or activated B-cell-like type (non-GCB-DLBCL). The most common type of primary central nervous system lymphoma is diffuse large B-cell type with poor prognosis and the reason is unclear. This study aims to stratify primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) according to the cell-of-origin (COO) and to investigate the multiple proteins expression of C-MYC, BCL-6, BCL-2, TP53, further to elucidate the reason why primary central nervous system diffuse large B-cell lymphoma possesses a poor clinical outcome as well. Nineteen cases of primary central nervous system DLBCL were stratified according to immunostaining algorithms of Hans, Choi and Meyer (Tally) and we investigated the multiple proteins expression of C-MYC, BCL-6, BCL-2, TP53. The Epstein-Barr virus and Borna disease virus infection were also detected. Among nineteen cases, most (15-17 cases) were assigned to the activated B-cell-like subtype, highly expression of C-MYC (15 cases, 78.9%), BCL-2 (10 cases, 52.6%), BCL-6 (15 cases, 78.9%). Unfortunately, two cases were positive for PD-L1 while PD-L2 was not expressed in any case. Two cases infected with BDV but no one infected with EBV. In conclusion, most primary central nervous system DLBCLs show an activated B-cell-like subtype characteristic and have multiple expressions of C-MYC, BCL-2, BCL-6 protein, these features might be significant factor to predict the outcome and guide treatment of PCNS-DLBCLs.

Frequent MYD88 L265P and CD79B Mutations in Primary Breast Diffuse Large B-Cell Lymphoma

Primary breast diffuse large B-cell lymphoma (PB-DLBCL) is a rare disease comprising <3% of extranodal lymphomas. It frequently reveals an activated B-cell (ABC)-like phenotype. ABC-like DLBCL was reported to have gain-of-function mutations in MYD88, CD79B, CARD11, and TNFAIP3, resulting in constitutive activation of the NFκB pathway. Because of the rare occurrence of PB-DLBCL, the frequency of MYD88 and CD79B mutations is still unknown. We used Sanger sequencing to study these mutations from 46 breast DLBCL cases and also investigated the associated clinicopathologic factors. MYD88 L265P was confirmed by allele-specific polymerase chain reaction and compared with the Sanger sequencing results. MYD88 L265P and CD79B mutations were detected in 27/46 (58.7%) and 11/33 (33.3%) cases, respectively. Twenty-eight of 46 cases met the criteria for PB-DLBCL, and the latter 18 cases were further classified as clinical breast DLBCL (CLB-DLBCL). The frequency of MYD88 L265P and CD79B mutations was 16/28 (57.1%) and 9/23 (39.1%), respectively, in PB-DLBCL and 11/18 (61.1%) and 2/10 (20%), respectively, in CLB-DLBCL. When the cutoff value was set at ΔCt≤1, the result of allele-specific polymerase chain reaction for MYD88 corresponded to those of the Sanger sequence at 92.6% sensitivity and 100% specificity. According to Choi's algorithm, 16/27 (59.3%) demonstrated an ABC-like phenotype in PB-DLBCL, and 15/18 (83.3%) demonstrated an ABC-like phenotype in CLB-DLBCL. In conclusion, MYD88 L265P and CD79B mutations were frequently detected in PB-DLBCL, and they may be key molecules associated with PB-DLBCL lymphomagenesis. Further analysis will be required to clarify the mechanism of its pathogenesis.

Primary breast lymphoma

Primary breast lymphoma is a rare form of extranodal lymphoma, defined by the presence of a primary lesion within the breast with or without regional nodal involvement but no other extra-mammary sites of involvement. It comprises diverse histologic subtypes, but diffuse large B-cell lymphoma is the most common. In this review, we describe in detail the clinical features, diagnosis and staging, pathogenesis, risk factors and therapy of primary breast diffuse large B-cell lymphoma. We consider choice and number of cycles of chemotherapy, the indications for radiotherapy and discuss the need for central nervous system prophylaxis. We also provide a brief overview of the less commonly encountered histologic subtypes including marginal zone, follicular, Burkitt and breast implant associated anaplastic large cell lymphoma. We conclude with a suggested treatment approach and potential areas of future research.

Primary breast diffuse large B cell lymphoma - report of 6 cases from South India with review of literature

The breast is an uncommon site of involvement in non-Hodgkin lymphoma, and primary breast lymphoma (PBL) is a disease localized to one or both breasts with or without regional lymph nodes involvement. The objectives of the study were to review the clinical profile, epidemiological parameters and assess the outcomes exclusively in women with primary diffuse large B cell lymphoma (DLBCL) of breast. This was a retrospective observational study done at Kidwai Memorial Institute of Oncology, Bangalore, India. We studied 6 consecutive female patients, diagnosed with primary DLBCL of breast between January 2007 and December 2011. Median age at diagnosis was 45 years (range 33-56 years). B symptoms were present in 3 patients. One patient had central nervous system involvement with high risk International Prognostic Index (IPI). 3 patients underwent lumpectomy and 3 core biopsy. All received anthracycline based chemotherapy, with rituximab in one patient and 3 received involved field radiotherapy. Three patients achieved complete response; one is disease free at 15 months. Two relapsed at 8 and 53 months and both were alive with disease. One achieved partial response, one had progressive disease and response was not assessed in one (but died due to toxicity). Primary breast DLBCL is a rare entity and multi modality combination therapy involving chemotherapy and radiation can give a longer overall survival and thus avoiding the morbidity of mastectomy.