CD20 is a surface marker protein of B-cell lymphoma, and its extracellular region is the target of specific antibodies and drugs. To obtain a cheap and easily modified specific preparation targeting CD20, we optimized the gene of CD20 extracellular region according to codon degeneracy to facilitate its expression in Escherichia coli. The optimized gene was cloned into pGEX-4T-1 vector, and the recombinant vector was transformed into E. coli BL21(DE3) for expression. The purified protein was identified by SDS-PAGE and Western blotting. Systematic evolution of ligands by exponential enrichment (SELEX) was employed to screen the ssDNA aptamer that specifically binds to the fusion protein, and the affinity of the aptamer to CD20 was detected by flow cytometry. Then, the cytotoxicity test was carried out to examine the inhibitory effect of the aptamer on B lymphoma cells. In this study, we established the prokaryotic expression method of CD20 and obtained the aptamer specifically binding to the extracellular region of CD20, which laid a foundation for the development of therapeutic drugs targeting CD20.
Humans ; Escherichia coli/metabolism* ; SELEX Aptamer Technique/methods* ; Aptamers, Nucleotide/genetics* ; Antigens, CD20/metabolism* ; Ligands

OBJECTIVETo study the clinicopathologic features and significance of aberrant CD56 expression in diffuse large B-cell lymphoma (DLBCL).

METHODSThe clinical and pathologic profiles of 10 cases of DLBCL with aberrant expression of CD56 were investigated. Immunohistochemical staining, in-situ hybridization for Epstein-Barr virus encoded RNA and gene rearrangement for IgH and Igκ were carried out.

RESULTSThere were 6 male and 4 female patients. The medium age of patients was 46 years. All of them presented with extranodal lymphoma involvement, with gastrointestinal tract being the commonest site (5/10). Histologic examination showed that most of the atypical lymphoid cells were centroblast-like and demonstrated a diffuse growth pattern. Apoptosis and necrosis were identified in some cases. Immunohistochemical study showed that the tumor cells were positive for CD20 or CD79α and aberrantly expressed CD56. Five cases had the GCB phenotype while the remaining cases had the non-GCB phenotype, according to Hans classification. Bcl-6 was positive in most cases (9/10). All cases showed a high proliferation index by Ki-67. The tumor cells were negative for CD3ε, CD138 and granzyme B. In-situ hybridization for Epstein-Barr virus encoded RNA was performed in 7 cases and none of them showed positive signals. IgH gene rearranged bands were detected in 4 cases (4/6) and Igκ was detected in 3 cases (3/6). Follow-up data were available in 8 patients. Two patients died of disease progression within 5 to 13 months after diagnosis and the other 6 patients were alive 8 to 60 months after therapy.

CONCLUSIONSDLBCL with aberrant expression of CD56 is rare. Most of them present with extranodal involvement, show high frequency of bcl-6 expression and high proliferation index. The patients often have good response to chemotherapy.

Antigens, CD20 ; metabolism ; Apoptosis ; CD56 Antigen ; metabolism ; CD79 Antigens ; metabolism ; Disease Progression ; Female ; Gene Rearrangement ; Granzymes ; metabolism ; Herpesvirus 4, Human ; genetics ; Humans ; Immunophenotyping ; In Situ Hybridization ; Lymphoma, Large B-Cell, Diffuse ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Necrosis ; Phenotype ; Proto-Oncogene Proteins c-bcl-6 ; metabolism ; RNA, Viral ; analysis

BACKGROUND: Bone marrow biopsies are routinely performed for staging patients with B-cell non-Hodgkin lymphoma (NHL). In addition to histomorphological studies, ancillary tools may be needed for accurate diagnosis. We investigated the clinical utility of multiparameter flow cytometric examination of bone marrow aspirates. METHODS: A total of 248 bone marrow specimens from 232 patients diagnosed with B-cell NHL were examined. Monoclonal antibodies directed against CD19, CD20, CD10 (or CD5), and kappa and lambda immunoglobulins were used. Multi-stage sequential gating was performed to select specific cells of interest, and the results were compared with bone marrow histology. RESULTS: The concordance rate between histomorphology and flow cytometry was 91.5% (n=227). Eight cases (3.2%) were detected by flow cytometry alone and were missed by histomorphology analysis, and 6 of these 8 cases showed minimal bone marrow involvement (0.09-2.2%). The diagnosis in these cases included large cell lymphoma (n=3), mantle cell lymphoma (n=3), and mucosa-associated lymphoid tissue (MALT) lymphoma (n=2). Thirteen cases were histopathologically positive and immunophenotypically negative, and the diagnoses in these cases included diffuse large cell lymphoma (n=7), T-cell/histiocyte-rich large B-cell lymphoma (n=2), anaplastic lymphoma kinase (ALK)-positive large B-cell lymphoma (n=1), follicular lymphoma (n=1), MALT lymphoma (n=1), and unclassifiable lymphoma (n=1). CONCLUSIONS: Multi-color flow cytometry can be a useful method for assessing bone marrow in staging NHL and also plays a complementary role, especially in detecting small numbers of lymphoma cells.
Antibodies, Monoclonal/immunology ; Antigens, CD19/immunology/metabolism ; Antigens, CD20/immunology/metabolism ; Bone Marrow/*pathology ; Female ; Flow Cytometry ; Humans ; Immunophenotyping ; Lymphoma, B-Cell/*pathology ; Male ; Neoplasm Staging ; Neprilysin/immunology/metabolism

The sandwich sign is used to describe mesenteric lymphoma in which mesenteric vessels and fat are enveloped by enlarged mesenteric lymph nodes. We present two cases of primary pleural lymphoma demonstrating the "pleural sandwich sign". Contrast-enhanced computed tomography showed conglomerated parietal pleural and extrapleural masses encasing the intercostal arteries. Histopathological examinations confirmed low grade marginal zone B-cell lymphoma in an 80-year-old man and diffuse large B-cell lymphoma in a 68-year-old man. The pleural sandwich sign may suggest the diagnosis of primary pleural lymphoma.
Aged ; Aged, 80 and over ; Antigens, CD20/metabolism ; Antineoplastic Agents/therapeutic use ; Humans ; Lymphoma, B-Cell, Marginal Zone/*diagnosis/drug therapy/metabolism ; Lymphoma, Large B-Cell, Diffuse/*diagnosis ; Male ; Pleura/*pathology ; Pleural Neoplasms/*diagnosis/drug therapy/metabolism/pathology ; Positron-Emission Tomography ; Tomography, X-Ray Computed

Spontaneous gastric perforation is a rare complication of gastric lymphoma that is potentially life threatening since it can progress to sepsis and multi-organ failure. Morbidity also increases due to prolonged hospitalization and delay in initiating chemotherapy. Therefore prompt diagnosis and appropriate treatment is critical to improve prognosis. A 64-year-old man presented to the emergency department with severe abdominal pain. Chest X-ray showed free air below the right diaphragm. Abdominal CT scan also demonstrated free air in the peritoneal cavity with large wall defect in the lesser curvature of gastric lower body. Therefore, the patient underwent emergency operation and primary closure was done. Pathologic specimen obtained during surgery was compatible to diffuse large B cell lymphoma. Fifteen days after primary closure, the patient received subtotal gastrectomy and chemotherapy was initiated after recovery. Patient is currently being followed-up at outpatient department without any particular complications. Herein, we report a rare case of gastric lymphoma that initially presented as peritonitis because of spontaneous gastric perforation.
Abdominal Pain ; Antigens, CD20/metabolism ; Antigens, CD45/metabolism ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use ; Gastrectomy ; Humans ; Intestinal Perforation/diagnostic imaging ; Lymphoma, Large B-Cell, Diffuse/*diagnosis/drug therapy/pathology ; Lymphoma, Non-Hodgkin/*diagnosis/drug therapy/pathology ; Male ; Middle Aged ; Positron-Emission Tomography ; Stomach Neoplasms/*diagnosis/drug therapy/pathology ; Tomography, X-Ray Computed

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of extranodal diffuse large B-cell lymphoma that most commonly involves the central nervous system and skin. To our knowledge, no state-of-the art imaging findings have been reported for hepatic IVLBCL in the English literature. We report the first case of hepatic involvement of IVLBCL along with a literature review.
Antigens, CD20/metabolism ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use ; Humans ; Liver Neoplasms/drug therapy/*pathology/radiography ; Lymphoma, Large B-Cell, Diffuse/drug therapy/*pathology/radiography ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Remission Induction ; Rituximab/administration & dosage ; Tomography, X-Ray Computed

OBJECTIVETo profile the clinicopathologic features of a series of grey zone lymphoma (GZL) cases with hybrid features of diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin lymphoma (CHL), with a purpose to gain an in-depth understanding of the borderline B-cell neoplasm.

METHODSThe clinical, morphologic and immunophenotyical characteristics of 16 cases were retrospectively analyzed.

RESULTSThe patients were mostly male adults, with a male to female ratio of 1.7: 1.0 and a mean age of 40.2 years. Eight patients presented with peripheral nodal lesions and five cases with mediastinal involvement. Histologically and immunophenotypically, the 16 cases were classified into three sub-categories. In 4 cases, the morphologic features resembled CHL more closely, but the neoplastic cells showed uniform and intense positive staining of CD20 (pattern 1). Although the initial impression of the other 8 cases was that of DLBCL, the expression levels of CD20 and PAX5 were variable, and CD30 or CD15 was positive (pattern 2). A characteristic feature of pattern 3, observed in the remaining 4 cases, demonstrated a broad spectrum of morphology with hybrid features of both CHL and DLBCL. The neoplastic cells in pattern 3 were positive for CD20, CD30 and CD15. EBV-LMP1 was detected in 6 of the 11 tested cases. Clinically, most patients with GZL seemed insensitive to immuno-chemotherapy of the R-CHOP regimen.

CONCLUSIONSThe diagnostic criteria for GZL with features intermediate between DLBCL and CHL is proposed by the three histologic patterns commonly seen in these lesions. Cases presented with peripheral lesions might differ from those with mediastinal presentation pathologically. At current time, there is no effective treatment for these borderline B-cell lymphomas and the prognosis is poor.

Adolescent ; Adult ; Aged ; Antibodies, Monoclonal, Murine-Derived ; therapeutic use ; Antigens, CD20 ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cyclophosphamide ; therapeutic use ; Diagnosis, Differential ; Doxorubicin ; therapeutic use ; Female ; Hodgkin Disease ; drug therapy ; metabolism ; pathology ; Humans ; Ki-1 Antigen ; metabolism ; Lewis X Antigen ; metabolism ; Lymphoma, Large B-Cell, Diffuse ; drug therapy ; metabolism ; pathology ; Male ; Middle Aged ; PAX5 Transcription Factor ; metabolism ; Prednisone ; therapeutic use ; Prognosis ; Retrospective Studies ; Rituximab ; Vincristine ; therapeutic use ; Viral Matrix Proteins ; metabolism ; Young Adult

We report a case of primary mucosa-associated lymphoid tissue (MALT) lymphoma in the esophagus that manifested as a large submucosal tumor (SMT). Primary esophageal lymphoma is very rare, occurring in less than 1% of all patients with gastrointestinal lymphoma. Only a few cases of MALT lymphoma in the esophagus have been reported in the English literature. A 53-year-old man was referred to Dongguk University Ilsan Hospital (Goyang, Korea) in July 2012 for further evaluation and treatment of an esophageal SMT. Endoscopy showed a cylindrically elongated submucosal mass with normal overlying mucosa in the mid esophagus, 25-30 cm from the incisor teeth. He underwent surgery to confirm the diagnosis. Pathologic findings showed diffuse small atypical lymphoid cells which were stained with Bcl-2, CD20, but not with CD3, CD5, CD23, Bcl-6, or cyclin D1. These cells showed a positive monoclonal band for immunoglobulin heavy chain gene rearrangement. Based on the pathological, immunohistochemical, and molecular biological features, the esophageal mass was diagnosed as extranodal marginal zone B-cell lymphoma of the MALT type.
Antigens, CD20/metabolism ; Bone Marrow/pathology ; Esophageal Neoplasms/*diagnosis/pathology/surgery ; Gastroscopy ; Humans ; Immunohistochemistry ; Lymphoma, B-Cell, Marginal Zone/*diagnosis/pathology/surgery ; Male ; Middle Aged ; Mucous Membrane/pathology ; Proto-Oncogene Proteins c-bcl-2/metabolism ; Tomography, X-Ray Computed

OBJECTIVETo study the clinicopathologic features and differential diagnosis of splenic B-cell marginal zone lymphoma (SMZL) involving bone marrow.

METHODSThe clinical and pathologic features of 22 patients with SMZL were retrospectively studied. Immunophenotypic analysis was carried out by flow cytometry and immunohistochemistry. Immunoglobulin heavy chain rearrangement study was performed using polymerase chain reaction-based method.

RESULTSVillous lymphocytes were found in peripheral blood smears of 11/18 of the patients. In bone marrow aspirates, lymphocytosis (> 20%) was demonstrated in 15 cases (15/18) and villous lymphocytes in 6 cases (6/18). Flow cytometry showed CD19(+) CD20(+) FMC7(+) CD22(+) CD10(-) CD2(-) CD3(-) CD7(-) in 18 cases. Bone marrow biopsies of all the 22 patients revealed various degrees and patterns of neoplastic infiltration, as follows: mild (4 cases, 18.2%), moderate (11 cases, 50.0%) or severe (7 cases, 31.8%); intrasinusoidal (16 cases, 72.7%), interstitial (14 cases, 63.6%), nodular (11 cases, 50.0%) or diffuse (1 case, 4.5%). Reactive germinal center formation (CD23(+) bcl-2(-)) was found in 2 cases (91.0%). Immunohistochemical study showed the following results: CD20(+) PAX5(+) CD3(-) CD5(-) CD10(-) cyclin D1(-) CD23(-) CD43(-) Annexin A1(-) CD11C(-) CD25(-) in all the 22 cases, CD38(+) in 2 cases (9.1%) and CD138(+) in 2 cases (9.1%).

CONCLUSIONSDifferent and overlapping patterns of bone marrow involvement are observed in SMZL. As the histologic and immunophenotypic features are not specific to SMZL, distinction from other types of mature B-cell lymphomas is necessary.

Adult ; Aged ; Aged, 80 and over ; Antigens, CD20 ; metabolism ; Bone Marrow ; pathology ; Diagnosis, Differential ; Female ; Gene Rearrangement, B-Lymphocyte, Heavy Chain ; Humans ; Leukemia, Lymphocytic, Chronic, B-Cell ; metabolism ; pathology ; Lymphoma, B-Cell, Marginal Zone ; genetics ; metabolism ; pathology ; Lymphoma, Follicular ; metabolism ; pathology ; Lymphoma, Mantle-Cell ; metabolism ; pathology ; Male ; Middle Aged ; Neoplasm Invasiveness ; Retrospective Studies ; Splenic Neoplasms ; genetics ; metabolism ; pathology ; Waldenstrom Macroglobulinemia ; metabolism ; pathology

OBJECTIVETo identify the immunohistochemical patterns of follicular dendritic cell (FDC) meshwork and Ki-67 labeling index in small B-cell lymphomas (SBLs) and their significance in differential diagnosis.

METHODSSixty-eight cases of SBLs were included collected from November 2008 to June 2012. The patterns of FDCs and Ki-67 expression were studied on paraffin sections by CD21, CD23 and Ki-67 immunohistochemistry. The characteristic staining patterns of FDCs and Ki-67 expression among different SBLs were analyzed statistically.

RESULTSThe age of SBL patients ranged from 28 to 85 years with a mean of 55.2 years. The male to female ratio was 1.2:1. Fifty-five cases involved only lymph nodes (80.9%), and the remaining cases involved multiple extra-nodal sites. Histological classification of the cases was made according to the 2008 WHO lymphoma classification criteria: 22 were low-grade follicular lymphomas (FLs, including grade 1 and grade 2), 19 marginal zone lymphomas (MZLs), 17 mantle cell lymphomas (MCLs), and 10 chronic lymphocytic leukemia/small lymphocytic lymphomas (CLL/SLLs). FDC meshwork limited to the central part of neoplastic follicles was characteristic for FL (90.9%, 20/22). The germinal center FDC meshwork was destroyed primarily at periphery in MZL (14/19). The absence or scattered FDC clusters were typical of SLL/ CLL. Irregular FDC was seen in 7/17 of MCL, while 7/17 MCL displayed FDC pattern similar to that of CLL/SLLs. The pattern of FDCs was a significantly diagnostic feature in distinguishing the four types of SBLs (P < 0.01). Ki-67 was also a statistically significant parameter (P < 0.05) with decreasing labeling index as the following: MCL, FL, SLL and MZL. Ki-67 showed scattered pattern in germinal centers with loss of polarity in FLs. MZL presented uniformly scattered positive pattern in interfollicullar areas. Ki-67 staining was uniform in MCL, but its labeling index varied from 5% to 90%. The Ki-67 index was higher in the morphological "proliferation centers" of all CLL/SLLs.

CONCLUSIONImmunohistochemical staining patterns of FDC meshworks and Ki-67 labeling index offer a significant discriminatory power in the differential diagnoses among SBLs.

Adult ; Aged ; Aged, 80 and over ; Antigens, CD20 ; metabolism ; Dendritic Cells, Follicular ; pathology ; Diagnosis, Differential ; Female ; Humans ; Immunohistochemistry ; Ki-67 Antigen ; metabolism ; Leukemia, Lymphocytic, Chronic, B-Cell ; metabolism ; pathology ; Lymphoma, B-Cell ; classification ; metabolism ; pathology ; Lymphoma, B-Cell, Marginal Zone ; metabolism ; pathology ; Lymphoma, Follicular ; metabolism ; pathology ; Lymphoma, Mantle-Cell ; metabolism ; pathology ; Lymphoma, Non-Hodgkin ; metabolism ; pathology ; Male ; Middle Aged ; Receptors, Complement 3d ; metabolism ; Receptors, IgE ; metabolism ; Retrospective Studies