Double immunoenzymatic labeling of lymphomatous tissues for both immunologic phenotype and a malignancy-associated nucleolar antigen

Defining cell lineage in the non-Hodgkin's lymphomas (NHL) is challenging for the immunopathologist. Cell surface marker techniques have made a major contribution to the understanding of the biology and classification of lymphoproliferative disorders by permitting the determination of the lymphoid (B- or T-cell) or monocytic lineage of the tumors. Because lymphoma cells often simulate the morphologic features and cell surface phenotype of their normal lymphocytic counterparts, it is difficult to discriminate normal from neoplastic lymphocytes. The authors have used representative monoclonal antibodies (MAb) to cell surface antigens to assess tumor cell surface antigens associated with various lymphoreticular cell lineages. Heteroantisera to the human malignancy-associated nucleolar antigen (HMNA) was utilized as a marker for neoplastic lymphoid cells as previously described. The use of double immunoenzymatic staining with both peroxidase and alkaline phosphatase allow us simultaneously to determine lymphoid lineage and malignancy on human lymphoma cells. In 101 cases of various cell types of NHL, the anti-HMNA antiserum reacted with nucleoli in the morphologically neoplastic lymphoma cells, but not with normal-appearing lymphoid and other cell types present in the lesions. Control specimens from normal and hyperplastic lymphoid tissue also failed to react with anti-HMNA antibodies.     

T6 monoclonal antibody reacts with blasts from cases of common antigen acute lymphocytic leukemia

The expression of the T6 antigen on malignant lymphoid cells has been considered strong evidence in support of T-cell lineage and thymic stage of differentiation of the neoplastic cells. Thus, the authors have used the T6 monoclonal antibody for the last three years in the immunophenotyping of blasts from 60 consecutive cases of acute lymphocytic leukemia (ALL) and 8 cases of T-cell lymphoma. Blasts from 12 of 46 (26%) cases of common type ALL, 4 of 7 (57%) cases of T-cell ALL, 2 of 3 (66%) cases of lymphoblastic lymphoma, and 1 of 5 (20%) cases of peripheral (postthymic) T-cell lymphoma were positive for the T6 antigen. The authors conclude that the expression of T6 antigen on malignant lymphoid cells may not always indicate T-cell lineage.     

Aberrant expression of T-cell-associated antigens on B-cell non-Hodgkin lymphomas

We describe 9 well-characterized cases of B-cell non-Hodgkin lymphoma (NHL) that showed aberrant expression of T-cell-associated antigens by 2-color flow cytometry. Cases were as follows: chronic lymphocytic leukemia/small lymphocytic lymphoma, 4; follicle center cell lymphoma, 2; mantle cell lymphoma, 1; and diffuse large B-cell lymphoma, 2. CD2 was the most commonly expressed antigen (5 cases). CD8 and CD7 were identified in 2 cases each, including 1 case that expressed both CD7 and CD4. The disease course and response to treatment were compatible with the type and stage of lymphoma. No unusually aggressive behavior was noted in any case. A control group of 59 cases of benign lymph nodes analyzed during the same period showed no aberrant expression of T-cell-associated antigens; thus, such expression is not a feature of benign lymphoid proliferations. Study of these B-cell lymphomas may prove invaluable to study aberrant activation of silent or repressed T-cell differentiation genes. CD2-expressing B-cell NHLs may represent clonal expansion of CD2+ B lymphocytes that normally constitute a small fraction of peripheral B lymphocytes and should not be confused with composite B- and T-cell lymphomas. Unless aggressive behavior is noted consistently, no aggressive treatment is justified.     

Follicular dendritic cell sarcoma of small intestine with aberrant T-cell marker expression

Follicular dendritic cell sarcoma (FDCS) is an uncommon neoplasia usually occurring in lymphoid tissue. Herein is presented a case of FDCS of the small intestine with positivity for T-cell antigen, simulating T-cell lymphoma. An 82-year-old man consulted a doctor for a 1 week history of epigastric pain. Imaging indicated a mass in the small intestine. Malignant lymphoma was suspected because of high serum levels of soluble interleukin-2 receptor, and resection of the tumor was performed. Microscopically the tumor consisted of large pleomorphic cells with reactive small lymphocytes. Most of the nuclei of the tumor cells were round or ovoid, and some of the tumor cells also had spindle-shaped nuclei. Although the tumor cells were diffusely positive for CD45RO and CD4 on immunohistochemistry, negativity for pan-T-cell markers and CD56 was unusual for T-cell lymphoma of intestinal origin. Additional immunohistochemistry demonstrated that the tumor cells were positive for follicular dendritic cell markers including CD23, CD35 and CAN.42, and diagnosis of FDCS was made. To the authors' knowledge this is the first case of FDCS aberrantly expressing CD45RO; FDCS expressing T-cell markers can be a pitfall for diagnosis of FDCS.     

CD4+CD56+ lineage negative hematopoietic neoplasm: so called blastic NK cell lymphoma

Blastic natural killer (NK) cell lymphoma is a rare neoplasm characterized by blastoid tumor cells expressing CD4 and CD56, with predominant skin involvement. Although this tumor has been regarded as a neoplasm related to NK cell, recent studies suggested that it is derived from plasmacytoid dendritic cells, but not from NK cell. Herein we report 4 cases of CD4+CD56+ lineage marker-blastic NK cell lymphomas with a review of literatures. The patients were 3 men and one woman. Three of them were young (17, 18, and 22 yr old). Three patients had skin lesions, at initial presentation in two patients and during the course of disease in other patient. Histologically, tumors consisted of monotonous medium to large blastoid cells showing no necrosis, angiocentric growth or epidermotrophism. All four tumors were CD4+ and CD56+. Three expressed CD68 antigen. Lineage specific markers for B- and T cell were negative. All tumors did not express myeloperoxidase. T-cell receptor gene rearrangement, EBV, CD13 and CD33 were negative. In one patient, tumor cells arranged in Homer-Wright type pseudorosette and expressed terminal deoxynucleotidyl transferase(TdT). Despite the standard lymphoma chemotherapy, the tumors, except one lost during follow-up, progressed and relapsed. The patients died 8-60 months after diagnosis.     

Lymphoblastic lymphoma with the phenotype of common acute lymphoblastic leukemia

Immunologic phenotyping of lymphoblastic lymphomas has shown that most of these are tumors of T-cell origin. In this report, we describe two patients with biopsy-proven lymphoblastic lymphoma whose tumors had no T-cell markers when tested by immunoperoxidase with a large panel of monoclonal antibodies. However, the tumor cells did express the common ALL antigen (CALLA), Ia antigen, and a 24,000 dalton ALL-associated antigen defined by monoclonal antibody DU-ALL-1. The tumor cells also lacked surface immunoglobulin. Although this phenotype is that seen in most cases of acute lymphoblastic leukemia, the patients were never leukemic at any time during their clinical course. Our results support the overall similarity between lymphoblastic lymphoma and acute lymphoblastic leukemia. Further, they suggest that it may be possible to identify prognostically significant immunologic subtypes of lymphoblastic lymphoma.     

Expression of the promyelocytic leukemia zinc-finger in T-lymphoblastic lymphoma and leukemia has strong implications for their cellular origin and greater association with initial bone marrow involvement

The promyelocytic leukemia zinc-finger (PLZF) is essential for the development of innate T cells (as represented by natural killer T cells) for acquisition of their unique innate immune properties. We evaluated the PLZF protein expression in a variety of immature and mature lymphoid malignancies. PLZF was preferentially expressed in T-lymphoblastic lymphoma/acute lymphoblastic leukemia (T-LBL/ALL) in 50% of the 54 cases. Among 51 cases of peripheral T-cell lymphoma not otherwise specified, only one (2%) expressed PLZF. One mycosis fungoides case expressed PLZF in lymph node involved by tumor. Otherwise, PLZF was not detected in any other type of lymphoma. In T-LBL/ALL, PLZF expression was more common in CD4/CD8 double-negative (67%) or CD8 single-positive subtypes (73%) than in CD4/CD8 double-positive (13%) and CD4 single-positive subtypes (0%) (P=0.001). Importantly, PLZF and CD1a expression were mutually exclusive in T-LBL/ALL (P=0.001). This was also the case for T-cell receptor βF1 expression (P=0.000). Most (96%) of the PLZF-positive T-LBL/ALL cases showed initial bone marrow involvement compared with 39% of PLZF-negative cases (P=0.000). Based on these findings, we suggest that T-LBL/ALLs that express PLZF arise from early immature double-negative thymocytes when the T-cell receptor β chain has not yet expressed or innate T-cell precursors, and strongly imply bone marrow involvement.     

Plasmablastic lymphoma in a patient with HIV infection: an unusual case located in the skin

We report the case of a plasmablastic lymphoma involving the skin in a 45 year-old HIV-positive patient. Plasmablastic lymphoma was first described in 1997 and is considered to be a diffuse large B-cell lymphoma with a unique immunophenotype and a predilection for the oral cavity. In this case, the tumor was revealed by multiple purple cutaneous nodules predominantly localized on the trunk and proximal parts of the limbs. A skin biopsy led to the diagnosis of plasmablastic lymphoma in view of the presence of a dense nodular infiltrate invading the dermis and subcutaneous fat composed of large cells that expressed neither the leucocyte common antigen nor the B- and T-cell antigens CD20 and CD3, but which showed a strong immunostaining with plasma cell marker VS38c. Most of the cells expressed Kappa light chain of immunoglobulins, they did not express Lambda light chain. In situ hybridization with EBER probe revealed detection of Epstein Barr virus in about 15 % of tumor cells. The clinical course was aggressive and rapidly fatal. Despite one cycle chemotherapy the patient died four months after presentation. HIV-associated plasmablastic lymphoma is a poor prognosis malignancy that may resist typing due to the lack of expression of commonly used lymphoid markers.     

Immunophenotypic analysis of acute lymphoblastic leukemia using routinely processed bone marrow specimens

Monoclonal antibodies have been recently developed that react with antigens expressed on T and B lymphocytes in routinely processed, paraffin-embedded lymphoid tissues. In this study, we assessed bone marrow clot and/or core biopsy sections of 19 cases of acute lymphoblastic leukemia (ALL) using routinely decalcified, B5- or formalin-fixed, paraffin-embedded sections and a panel of monoclonal antibodies, including LN1, LN2, L26, Leu-22, UCHL-1, and LCA. Each case had been previously phenotyped using freshly obtained aspirate material and a standard immunophenotypic protocol. Our results demonstrate the utility of the LN2 antibody in differentiating between precursor B-cell (pre-B) and precursor T-cell ALL. The LN2 antibody stained 11 of 12 cases of pre-B ALL and did not react with any of the seven T-cell ALLs. The other antibodies tested were less helpful. The Leu-22 antibody stained both pre-B and T-cell ALLs, while the results with UCHL-1 revealed peculiar nuclear staining of pre-B and T-cell ALLs; this we attributed to processing artifact. The L26 antibody reacted with only one case of pre-B ALL (also CD20 antigen positive), while the LN1 antibody did not react with any pre-B ALLs. Neither L26 nor LN1 stained any cases of T-cell ALL. The LCA antibody stained in only four (21%) of 19 cases, two pre-B and two T-cell ALLs. The results also suggest that this panel of antibodies may be useful in differentiating ALL from mature B-cell and T-cell lymphomas involving the bone marrow.     

血管免疫母细胞性T细胞淋巴瘤的形态及免疫表型研究

目的 研究血管免疫母细胞性T细胞淋巴瘤(AITL)形态学特点、特异性标志物,并探讨AITL中滤泡树突状细胞网的增生状况及其起源.方法 对29例AITL行bcl-6、CD10、CXCL13、CD21染色(EliVision法)及bcl-6/CD3、CD10/CD21及CD10/CD20双重染色,并选取外周T细胞淋巴瘤,非特殊类型(PTL-U);结外NK/T细胞淋巴瘤,鼻型;间变性大细胞淋巴瘤(ALCL);肠病性T细胞淋巴瘤(ETTL);皮下脂膜炎性T细胞淋巴瘤及淋巴结反应性增生作为对照.结果 (1)22例(75.9%)AITL表达CD10,对照组除1例PTL-U外均阴性;24例(82.8%)AITL表达CXCL13,所有PTL-u均阴性;而AITL中bcl-6的表达情况和PTL-u及反应性增生病例有一定程度的交叉.(2)29例AITL显示特征性的CD21阳性滤泡树突状细胞网增生,4例具有明显生发中心的病例,2例显示增生的滤泡树突状细胞网覆盖并超过生发中心.结论 AITL具有典型的形态学变化,CD10和CXCL13是AITL特异性标志物,而bcl-6不具有特异性;AITL中增生的滤泡树突状细胞网可能部分起源于生发中心.     

Combined Therapy with Rituximab Plus Cyclophosphamide/Vincristine/Prednisone for Sjogren’s Syndrome-Associated B-Cell Non-Hodgkin’s Lymphoma

Sjogren’s syndrome (SS) is characterized by an increased risk of developing non-Hodgkin’s lymphoma (NHL). Optimal treatment for NHL-complicating SS is not clearly established. NHL, which expresses the CD20 antigen on tumor cell surfaces, is a disease entity candidate to treatment with anti-CD20 monoclonal antibodies. We report clinical and immunological data of a patient with SS and NHL who was treated with a regimen consisting of cyclophosphamide/vincristine/prednisone (CVP) plus rituximab. A 68-year-old women had a 26-year history of SS and autoimmune thyroiditis. The clinical course of SS was complicated with severe splenomegaly. An increased percentage of CD19+ B cells (up to 30%) was detected in peripheral blood during follow-up. Clonal rearrangement of immunoglobulin heavy chain was detected. Low-grade B marginal zone lymphoma was diagnosed (peripheral blood immunophenotype: CD19 + CD20 + CD23 + sIg + Kappa; bone marrow immunophenotype: 25% lymphocytes; CD19 + CD20 + CD79A/BCL2+). She received a total of six cycles of CVP plus rituximab (375 mg/m²). Therapy was well tolerated, and B lymphocytes were depleted from the peripheral blood. Splenomegaly normalized. No evidence of neoplastic infiltration was detected in bone marrow after completion of therapy, while certain symptoms of SS (sicca and arthralgia) improved with treatment. CVP plus rituximab proved effective in a patient with SS with NHL.     

TDT (-), KIT (+), CD34 (+), CD99 (+) precursor T lymphoblastic leukemia/lymphoma

Although the definition of precursor T lymphoblastic lymphoma (T-LBL) is based only on histopathology, most cases cannot be diagnosed only by HE sections. Since 95% of T-LBL expresses TdT and TdT is expressed only in lymphoblasts, immunohistochemical demonstration of TdT is mandatory for the diagnosis of TLBL. However, little is known about the expression of other precursor cell molecules. A 58-year-old woman with myelodysplastic syndrome (RAEB) became overt acute myelogenous leukemia (AML). She was treated twice with allogeneic peripheral blood stem cell transplantation from her son. Nine months later, imaging modalities detected a soft tissue tumor around the left ileal bone. A biopsy was performed. Histologically, the tumor cells were malignant polymorphic lymphoid cells with hyperchromatic nuclei and inconspicuous nucleoli. Immunohistochemically, the tumor cells are positive for CD45, CD45RO, CD34, KIT (CD117), CD99 (MIC-2), p53, CD10, PDGFRA, and Ki67 (labeling=60%). They were negative for pancytokeratin AE1/3, pancytokeratin CAM5.2, TdT, CD3, CD20, CD79α, CD43, CD56, CD57, CD30, bcl-2, κ-chain, λ-chain, cytokeratin (CK) 7, CK20, synaptophysin, chromogranin, smooth muscle actin, p63, MPO, CD68, lysozyme, and ASD esterase. Although TdT was negative, other precursor cell markers (KIT, CD34, and CD99) were positive and the lymphoid cells showed T-cell lineage, the diagnosis was T-LBL. The patient died of lymphoma/ leukemia 11 months after the diagnosis. The author stress that TdT, KIT, CD34 and CD99 should be included in panels of precursor T-cell neoplasms. In addition, the author think that KIT, CD34 and CD99 are helpful for the diagnosis of T-LBL in cases negative for TdT. Further, it is unique that this case was not myeloid sarcoma but precursor T-cell neoplasm, and that T-LBL develops during AML.     

Identification of altered MicroRNA expression in canine lymphoid cell lines and cases of B- and T-Cell lymphomas

Canine lymphoma is a common spontaneous tumor with many similarities to human lymphoma, and thus has potential to be an important animal model of lymphomagenesis. This study determined that microRNA (miRNA) expression in canine tumors can be assessed using a commercially available human cancer miRNA qPCR array. miRNA expression in six different canine lymphoid cell lines and in naturally occurring canine B- and T-cell lymphomas was compared using RNA harvested from normal canine peripheral blood mononuclear cells (PBMC) and normal lymph nodes (LN) as controls. We found that false discovery rate (FDR) correction for multiple testing after quantile normalization controlled for variation across arrays and that they were the best methods for normalization and statistical analysis. Increases in miRNAs known to upregulate oncogenes (miR19a+b, miR17-5p) and decreased expression of miRNAs with tumor suppressor functions (miR-203, miR-218, and miR-181a) also seen in human lymphoid malignancies were observed. However, there were few similarities between canine groups. The results of this study indicate that the use of both PBMC and LN cells as controls provides different, but potentially equally important targets for further analysis. Our findings of miRNA dysregulation in canine lymphoid cell lines and clinical cases of lymphoma emphasize the potential of canine lymphoma as an important spontaneous, large animal model of human B- and T-cell lymphomas.     

Composite diffuse large B-cell lymphoma and CD20-positive peripheral T-cell lymphoma

Composite lymphoma is defined as two or more distinct types of lymphoma in a single anatomical site. Among various combinations, composite B-cell and T-cell non-Hodgkin's lymphomas (CBTL) are very infrequent. Herein we describe a 66-year-old female with CBTL presenting with lymphadenopathy, multiple bone lesions and an epidural tumor. Light microscopic examination of a biopsied cervical node revealed a dual population of lymphoid cells: sheets of large cells admixed with medium-sized cells. The large cells expressed B-cell markers and showed immunoglobulin light chain restriction, consistent with diffuse large B-cell lymphoma (DLBCL). The medium-sized cells were positive for CD20 as well as T-cell markers. Because polymerase chain reaction amplification showed monoclonal rearrangement of the T-cell receptor β chain gene, this population was compatible with peripheral T-cell lymphoma not otherwise specified (PTCL-NOS). We therefore made a diagnosis of composite DLBCL and CD20-positive PTCL-NOS. Complete remission was achieved after six cycles of R-CHOP regimen (rituximab, doxorubicin, vincristine, cyclophosphamide and prednisolone). This is the first report of CD20-positive PTCL-NOS associated with composite lymphoma. Moreover, a literature review of composite DLBCL and PTCL-NOS indicates that this rare clinical entity may be featured by efficacy of systemic chemotherapy in spite of prevalent extranodal lesions.     

CD40 ligand is constitutively expressed in a subset of T cell lymphomas and on the microenvironmental reactive T cells of follicular lymphomas and Hodgkin's disease.

Although CD40 has been extensively studied in B- and T-cell non-Hodgkin's lymphomas (NHLs)/leukemias, and more recently in Hodgkin's disease (HD), little is known about the expression of its ligand (CD40L) in lymphoproliferative disorders other than T-cell NHLs/leukemias. A series of 121 lymphoma/leukemia samples, including 35 cases of HD, 34 T-cell and 39 B-cells NHLs, 2 cases of adult T-cell leukemia/lymphoma, and 11 cases of T-cell acute lymphoblastic leukemia, were evaluated for CD40L expression by immunostaining of frozen tissue sections and flow cytometry with the anti-CD40L monoclonal antibody M90. CD40L was constitutively expressed by neoplastic cells in 15 of 36 (42%) T-cell NHLs/adult T-cell leukemia/lymphomas, almost invariably those displaying the CD4+/CD8- phenotype, whereas no CD40L-expressing tumor cells could be found in B-cell NHL and HD. Among T-cell acute lymphoblastic leukemias, CD40L was detected only on 2 cases displaying a stem-cell-like phenotype. In follicular B-cell lymphomas a large number of CD40L-expressing CD3+/CD4+ T lymphocytes were found admixed with tumor cells within the neoplastic follicles and in their surrounding areas. In the nonfollicular B-cell lymphomas, CD40L-positive CD3+/CD4+ T lymphocytes were few or absent. In all HD subtypes other than the nodular lymphocytic predominance, CD40L-expressing CD3+/CD4+ T lymphocytes were numerous in the HD-involved areas and were mainly located in close proximity to the Reed-Sternberg cells. Our data indicate that in human lymphomas CD40L is preferentially expressed by a restricted subset of T-cell lymphomas, mostly with CD4 immunophenotype. Finally, we have provided morphological evidence that CD40L may play an important role in the cell contact-dependent interaction of tumor B-cells (CD40+) within the neoplastic follicles or Reed-Sternberg cells (CD40+) in HD-involved areas and the microenvironmental CD3+/CD4+/CD40L+ T lymphocytes.     

Flow cytometry in the differential diagnosis of lymphocyte-rich thymoma from precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma

We compared the antigen expression profile of thymocytes in lymphocyte-rich thymoma with that of precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (T-cell ALL/LBL) cells using 4-colorflow cytometry. In all 15 thymoma cases, the thymocytes demonstrated 3 distinct subpopulations. The least mature cells (double-negative) expressed low-density CD2 and CD5, high-density CD7, CD10, CD34, and heterogeneous CD4 and CD8. They had the lowest density CD45 expression and were surface CD3-. The immature cells (double-positive) expressed CD2, CD5, CD7, CD4, CD8, heterogeneous surface CD3, and intermediate-density CD45. They were CD10- and CD34-. The mature cells (single-positive) expressed CD2, surface CD3, CD5, CD7, and CD4 or CD8. The heterogeneous expression of surface CD3, CD4, and CD8 also created a characteristic smearing pattern for these antigens. In all 15 T-cell ALL/LBL cases, the lymphoblasts formed a tight cluster without discrete subpopulations or smearing pattern. Of 5 double-negative cases, 4 demonstrated loss of CD2, CD10, or CD34 expression. Of 7 double-positive cases, 5 showed complete loss of surface CD3, CD2, and/or CD5; 4 were CD10+; and 2 were CD34+. Of 3 single-positive cases, 2 showed loss of CD2 and/or aberrant expression of CD34. Analysis of antigen expression pattern, the presence or absence of T cell-associated antigen deletion, and the expression of CD10 and CD34 by 4-color flow cytometry can help differentiate thymoma from T-cell ALL/LBL.     

Biclonality of composite B- and T-cell lymphomas. A case report

Most composite lymphomas which are composed morphologically of two different tumor cell types are considered to represent different morphological expressions of a single clone. However, in recent years, composite B- and T-cell lymphomas and biclonality of B-cell lymphoma have been reported. We experienced a case of composite lymphoma which initially developed as cutaneous lymphoma composed of lymphoplasmacytes associated with large clear cells. It was confirmed that the tumor cells of these two systems were biclonal on the basis of surface markers and DNA rearrangements, i.e. B cells of the IgG kappa type, showing IgH and kappa chain DNA rearrangement, and T-cells with CD4 surface marker, showing rearrangement of the T-cell receptor beta chain gene. This case showed a predominant B-cell pattern at the initial stage, and terminated in T-cell lymphoma, as revealed at autopsy. Therefore we considered this case to be a unique composite lymphoma showing biclonality of both B- and T-cell systems, providing a number of suggestions for future study of malignant lymphoma.     

Precursor T-cell acute lymphoblastic leukemia/lymphoma involving the uterine cervix,myometrium, endometrium,and appendix

This report presents a case of precursor T-cell acute lymphoblastic leukemia/lymphoma (ALL) involving the uterine cervix, myometrium, endometrium, and appendix. The patient was a 38-year-old woman with a history of ALL who had been in remission for 4 years following chemotherapy. The malignant lymphoid infiltrate was characterized by blasts, showing scant cytoplasm, irregular hyperchromatic nuclei, and occasional prominent nucleoli. They were immunoreactive for CD45RB, CD3, CD43, CD34, and focally for TdT. Curiously, the blasts replaced the endometrial stroma and spared the associated epithelium. The patient was again treated with chemotherapy but her disease did not respond. She succumbed to her disease approximately 10 months after her initial evaluation for symptoms related to ALL relapse. Precursor T-cell ALL most commonly presents as a mediastinal mass in adolescent males. Although any organ may be affected, involvement of the female reproductive organs is rare. This case shows some of the varied manifestations of precursor T-cell ALL and highlights the necessity of considering the female reproductive tract as a possible location of relapsing disease.