The world health organization classification of malignant lymphomas in japan: incidence of recently recognized entities. Lymphoma Study Group of Japanese Pathologists

New insights into the immunology and genetics of malignant lymphomas have allowed the recognition of new entities and the refinement of previously recognized disease categories. The relative incidence of these subtypes of malignant lymphoma is also known to differ according to geographic location. In order to clarify the current status of malignant lymphomas in Japan and the relative incidences of their subtypes, 3194 patients were classified according to the new World Health Organization (WHO) classification. Among these were 3025 cases (94.71%) of non-Hodgkin's lymphoma (2189 cases (68.53%) of B-cell lymphoma, 796 cases (24.92%) of T-cell lymphoma) and 141 cases (4.41%) of Hodgkin's lymphoma. The incidences of the major subtypes of non-Hodgkin's lymphoma were 33.34% for diffuse large B-cell lymphoma, 8.45% for marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type, 8.05% for plasma cell myeloma, 7.45% for adult T-cell leukemia/lymphoma (ATLL), 6.7% for follicular lymphoma, 6.67% for peripheral T-cell lymphoma of unspecified type, 2.79% for mantle cell lymphoma, 2.6% for nasal and nasal-type T/NK cell lymphoma, 2.35% for angioimmunoblastic T-cell lymphoma, and 2.35% for precursor B-cell lymphoblastic leukemia/lymphoma, in decreasing order. The other subtypes comprised less than 2%, mainly precursor T-cell lymphoblastic lymphoma/leukemia (1.72%), anaplastic large-cell lymphoma of T- and null-cell types (1.53%), and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (1.31%). The incidence of ATLL was influenced by its high percentage (19.20%) in the south-western Japanese island, Kyushu, an endemic area of human T-cell leukemia virus type 1 (HTLV-1), but which appeared to be lower than that in a previous study. The nodular sclerosis and mixed cellularity types of Hodgkin's disease occupied 1.78% and 1.63%, respectively. These data are distinct from those in Western countries and similar in several ways to those in the East, although the relatively high rate of ATLL was attributed to the geographical difference in the etiologic factor, HTLV-1.     

Clinicopathological analysis of 143 primary malignant lymphomas in the small and large intestines based on the new WHO classification

AIM: To study the clinicopathological and immunohistochemical features of 143 cases of primary small and large intestinal non-Hodgkin's lymphoma (NHL) in Japanese patients who presented between 1981 and 2000. METHODS AND RESULTS: The new World Health Organization (WHO) classification was used to classify NHL. The patients included 109 males and 34 females, with an average age of 54.1 years. Tumour sites were as follows: ileocaecal (n = 51, 35.7%), ileum (n = 29, 20.3%), rectum (n = 13, 9.1%), and duodenum (n = 11, 7.7%). Macroscopically, 124 cases (86.7%) were classified as tumorous type, 12 (8.4%) as diffuse infiltration type (erosion, superficial ulceration), five (3.5%) as polyposis type, and only two cases (1.4%) as ulceration type. Immunohistochemically, 122 lesions (85.3%) were of B-cell phenotype and 21 lesions (14.7%) were of T-cell phenotype. According to the WHO classification, of the B-cell lymphomas, 84 cases (68.9%) were large cell, 16 (13.1%) were Burkitt, 10 (8.2%) were marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT), and seven (5.7%) were mantle cell tumours. Among the T-cell lymphomas, 15 (71.4%) were of unspecified type, two (9.5%) were natural killer type, two were anaplastic large-cell lymphomas, one was lymphoblastic, and one was an adult T-cell leukaemia lymphoma. The survival rate for T-cell lymphomas was poorer than for B-cell lymphomas. Among the B-cell lymphomas, mantle cell lymphoma tended to have a poorer prognosis, whereas MALT lymphomas had a better prognosis than other B-cell tumour types. CONCLUSIONS: Our retrospective study of patients with primary malignant lymphomas in the small and large intestines has illustrated the clinical features and outcomes of patients with this disease.     

Frequency and diagnostic patterns of lymphomas in liver biopsies with respect to the WHO classification

The recent World Health Organization (WHO) classification of hematopoietic and lymphoid tissue tumors represents the first worldwide consensus classification of these malignancies. However, the applicability of this classification to a representative number of hepatic lymphomas in liver biopsy specimens has not yet been investigated. The frequency and infiltration pattern of a series of 205 liver biopsies with lymphoma manifestations was analyzed with the aid of immunohistochemical and molecular pathological analyses. Diffuse large B-cell lymphoma (DLBCL) was by far the most frequent entity, comprising 45% of the cases analyzed. Using a previously published immunohistochemical algorithm, 35% of 80 DLBCL were assigned to a germinal center B-cell-like (GCB) and 65% to a non-GCB group. Most B-cell lymphoma entities involving the liver revealed a characteristic infiltration pattern. Diagnostically challenging entities were T-cell-rich B-cell lymphomas, anaplastic large cell lymphomas and peripheral T-cell lymphomas, which frequently required additional molecular clonality assessment. Overall, the percentage of T-cell lymphomas in the liver (12%) was higher as compared to other extranodal sites except for the skin and the small intestine. This study provides relevant data on the distribution of hepatic lymphomas and demonstrates the applicability of the WHO classification proposing a diagnostic algorithm for liver biopsies.     

Distribution of malignant lymphoma in Japan: analysis of 2260 cases, 2001-2006

The World Health Organization classification was used to conduct an analysis of geographic, age, sex, and lesion primarily biopsied/resected distribution of 2260 lymphoid neoplasms diagnosed during 2001–2006 throughout Japan. B-cell neoplasms accounted for 65% of all lymphoid neoplasms, T/natural killer (T/NK)-cell neoplasms for 25% and Hodgkin lymphoma for 7%. The most common type was diffuse large B-cell lymphoma (DLBCL, 33%), followed by follicular lymphoma (18%), and adult T-cell leukemia/lymphoma (ATLL, 10%). The high rate of 18% for follicular lymphoma was similar to that in Western countries (11–33%). T/NK-cell neoplasms accounted for a higher percentage of lymphoid neoplasms in Kyushu (30%) and Okinawa (38%) compared with other areas of Japan (18–20%). Among T/NK-cell neoplasms, ATLL was the most common type in Okinawa (54%) and Kyushu (59%). Extranodal NK/T cell lymphoma was the second most common type of T/NK-cell neoplasms in Okinawa (15%). This epidemiological study shows that the distribution patterns of malignant lymphoma differ especially in Kyushu and Okinawa, the endemic area of human T-cell leukemia/lymphoma virus type 1.     

Immunohistochemical detection of BCL-3 in lymphoid neoplasms: a survey of 353 cases.

The bcl-3 gene at chromosome 19q13 encodes a member of the IkappaB family involved in regulating the NFkappaB pathway. Originally identified by its involvement in the rare t(14:19)(q32;q13), BCL-3 expression has never been analyzed in a wide variety of lymphomas. We assessed BCL-3 expression in 353 cases of non-Hodgkin lymphoma and Hodgkin lymphoma using formalin-fixed, paraffin-embedded tissue specimens, a monoclonal antibody specific for BCL-3, and immunohistochemical methods. Of 172 B-cell lymphomas, 10 (6%) were positive for BCL-3, including six of 23 (26%) diffuse large B-cell lymphoma, one of 17 (6%) small lymphocytic lymphoma, one of 26 (4%) follicular lymphoma, and two of 49 (4%) mantle cell lymphoma. All other B-cell neoplasms were negative, including marginal zone lymphoma (n=24, 11 extranodal, nine nodal, four splenic), Burkitt lymphoma (n=10), lymphoplasmacytic lymphoma (n=10), lymphoblastic lymphoma (n=8), and plasmacytoma (n=5). Of 111 T/NK-cell lymphomas, 25 (23%) were positive for BCL-3, including 13 of 40 (32%) anaplastic large-cell lymphoma, three of 10 (30%) angioimmunoblastic T-cell lymphoma, two of eight (25%) extranodal NK/T-cell lymphoma of nasal type, three of 12 (25%) mycosis fungoides, one of five (20%) enteropathy-type T-cell lymphoma, and two of 21 (10%) peripheral T-cell lymphoma unspecified. All other T-cell neoplasms were negative, including lymphoblastic lymphoma (n=6), prolymphocytic leukemia (n=6), and subcutaneous panniculitis-like T-cell lymphoma (n=3). Of 70 Hodgkin lymphomas, of all types, 29 (41%) were positive for BCL-3. The relatively high frequency of BCL-3 expression in some non-Hodgkin and Hodgkin lymphoma types raises the possibility that BCL-3 is involved in the pathogenesis of these tumors, and may be a target of new therapies.     

Classification of cell lineage and anatomical site, and prognosis of extranodal T-cell lymphoma – natural killer cell, cytotoxic T lymphocyte, and non-NK/CTL types

Due to their minority among the non-Hodgkin lymphomas, classification of extranodal T-cell lymphomas, including those of the natural killer (NK) cell type, has long been controversial and unclear, and the clinical outcome is not well clarified. Recently, new well-defined disease entities have been described based on tumor cell biology combined with anatomical site, clinical features, Epstein-Barr virus (EBV) status, and cell lineage as determined by immunophenotype and genotype. Cytological features are usually not specific, and there are no morphologic correlates with the classification of extranodal T/NK-cell lymphomas. From a human T-cell lymphotropic virus type 1 (HTLV-1) endemic area in Japan, we report here the analysis of 144 cases of extranodal T-cell lymphoma, from which fresh tissues were available. As the clinicopathological features were known, we simply reclassified the cases according to cell lineage and anatomical site. The extranodal T-cell lymphomas were classified into three types on the basis of cell lineage: (1) natural killer cell (NK) type [sCD3-, CD56+, T-cell receptor gene (TCR) germline], (2) cytotoxic T lymphocyte (CTL) type [sCD3+, TIA-1+, TCR rearranged, CD8+/-, CD4-/+], and (3) non-NK/CTL type [sCD3+, TIA-1-, TCR rearranged, CD4+/-, CD8-/+]. In addition to cell lineage, the anatomical site and clinical features were added for subclassification. NK type tumors (35 cases) included the lymphoblastic type, nasal/nasal-type NK lymphoma, and NK leukemia. The CTL type (46 cases) included anaplastic large cell lymphoma (ALCL), cutaneous type, intestinal, gamma delta T-cell type, and an unspecified type. The non-NK/CTL type (63 cases) included adult T-cell leukemia/lymphoma (ATLL), mycosis fungoides (MF), and an unspecified type. With the exception of ATLL and MF, most extranodal T-cell lymphomas had a cytotoxic phenotype of NK type or CTL type and were often associated with EBV infection. MF and the unspecified type within the non-NK/CTL tumors, with the exception of ATLL, had a favorable prognosis. However, NK and CTL types, with the exception of ALCL, were associated with a poor prognosis. Our results indicate that anatomical site and cell lineage are useful predictors of clinical outcomes of extranodal T-cell lymphomas.     

Peripheral T/NK-cell lymphoma: a report of the IXth Workshop of the European Association for Haematopathology

AIMS: In April 1998, The European Association for Haematopathology organized the IXth workshop on peripheral T-cell and NK-cell lymphomas and leukaemias. The workshop focused on unusual subtypes of these rare malignancies, allowing evaluation of the recently published WHO classification of neoplastic diseases of the lymphoid tissues. METHODS AND RESULTS: One-hundred and three cases were centrally immunophenotyped and hybridized for EBER1/2 of Epstein--Barr virus. All cases were reviewed by a panel of experienced haematopathologists and classified according to the new WHO classification for lymphoid neoplasms. Three cases were considered as precursor T-cell and 95 cases as peripheral T/NK-cell lymphoma/leukaemia. Although the cases represented a selected series of unusual cases, the following conclusions could be made: (i) Most lymphomas except the hepatosplenic gamma/delta T-cell lymphomas showed a rather broad morphological spectrum, with differences both between and within individual tumours. (ii) This heterogeneity was also reflected by the immunophenotype, for instance a variable expression of CD30 was found in many enteropathy type T-cell lymphomas. (iii) Exceptions in phenotype were regularly found in almost all categories, indicating that phenotype should not be the final determining factor in classification. (iv) The great majority of T-cell lymphomas expressed the alpha/beta T-cell receptor, with the exception of all but one hepatosplenic T-cell lymphomas and a few other extranodal peripheral T cell lymphomas. (v) Malignancies of precursor cells, blastic NK-cell lymphoma/leukaemia, adult T-cell lymphoma/leukaemia and most AIL-type T-cell lymphomas did not express cytotoxic molecules such as TIA1 and granzyme-B. In contrast, all five aggressive NK/T-cell lymphomas/leukaemias, a single case of large granular lymphocyte leukaemia and 40 of 47 primary extranodal lymphoma/leukaemias expressed these molecules. In hepatosplenic gamma/delta T-cell lymphoma, five of six cases showed expression of TIA1 but not of granzyme-B. (vi) Seven tumours developed after organ-transplant, four cases being EBV-positive. No distinct phenotype could be attributed to these cases. CONCLUSIONS: Most peripheral T/NK cell lymphomas could be categorized as distinct entities as described in the recently proposed WHO classification for lymphoid neoplasms.     

Monoclonal antibody HML-1 reactivity with adult T-cell leukaemia/lymphoma and other lymphomas

Human T-cell leukaemia/lymphoma virus type 1 (HTLV-1), a causative virus of adult T-cell leukaemia/lymphoma (ATLL), is known to be transmitted by breast-feeding. Using a monoclonal antibody HML-1 which labels human intestinal intra-epithelial T lymphocytes, we have immunohistochemically examined ATLL tissues in order to evaluate the possibility that HTLV-1 infected intestinal T cells are the origin of ATLL cells. Previously this antibody was reported to react with intestinal T-cell malignant lymphomas but not with peripheral tumours, or any B-cell lymphomas. We investigated 181 patients with malignant lymphomas and found that 19 out of 113 ATLLs were positive for HML-1. T-cell malignant lymphomas excluding ATLL also reacted with HML-1 (7/24), but all the B-cell lymphomas 0/33) and non-neoplastic lymph node and skin lesions (0/10) were negative for HML-1. In patients with ATLL and other T-cell malignant lymphomas, the positivity level of HML-1 was relatively higher in stomach (3/7) and tonsil (2/6) than that in lymph nodes (15/100) and skin (8/47). We observed one HML-1 positive ATLL patient with tumour formation in the skin and lymphadenopathy and marked infiltration of the large intestine but minimal involvement of other organs. Although HML-1 was frequently expressed in gastric infiltration of ATLL, the level of positivity was too low in lymph nodes to support the hypothesis that HTLV-1 infected intestinal T cells are the origin of ATLL cells. Some of the HML-1 positive ATLL cases co-expressed CD30. Furthermore, three of six cases of Ki-1 lymphoma (large anaplastic cell lymphoma) were positive for HML-1. We conclude that expression of HML-1 in ATLL reflects an activated state of the lymphoma cells, but not the intestinal origin of ATLL cells.     

应用2008版WHO造血和淋巴组织肿瘤分类对4例母细胞性NK细胞淋巴瘤重新评估

目的 探讨2008版WHO淋巴造血系统分类对母细胞性NK细胞淋巴瘤的重新分类和命名,观察此类淋巴瘤的组织形态、免疫表型分型及临床特点,并探讨其起源.方法 对符合2001版WHO造血和淋巴系统肿瘤分类(WHO分类)中母细胞性NK细胞淋巴瘤标准的4例,结合临床特点,观察其组织学形态、行免疫组织化学EliVision法染色,按2008版WHO分类进行重新分类.结果 4例的组织形态均呈母细胞性NK细胞淋巴瘤改变,CD56阳性,不表达T、B细胞和髓系标记,EBER原位杂交4例均阴性,均符合2001版WHO分类中NK母细胞性淋巴瘤的诊断标准.按2008版WHO分类,3例原发于皮肤,表达CD56、CD4和CD123,应诊断为母细胞性浆细胞样树突细胞肿瘤;1例发生于淋巴结,CD56和CD4阳性,CD123阴性,也无皮肤病变,只能暂时纳入来源不确定的白血病-NK细胞淋巴母细胞白血病/淋巴瘤.结论 2001版WHO分类中所谓的母细胞性NK细胞淋巴瘤实际上是一组异源性肿瘤,具有不同的免疫表型和临床特点,对此类肿瘤的细化分类和准确命名是2008版WHO淋巴瘤分类的一大进步.     

The application of antigen receptor gene rearrangement of BIOMED-2 in the pathologic diagnosis of 348 cases with non-Hodgkin lymphoma in a single institution in Southwest of China

ObjectiveTo explore the clinical value of immunoglobulin (Ig) and T cell receptor (TCR) gene rearrangement in the diagnosis of non-Hodgkin lymphoma.MethodsUsing the standardized BIOMED-2 multiplex PCR strategy to detect IgH, IgK and TCR in 272 cases of mature B-cell lymphoma, 55 cases of mature T-cell lymphoma, 21 cases of extranodal NK/ T-cell lymphoma, nasal type, and 20 cases of lymphoid tissue reactive hyperplasia.ResultsAmong all mature B-cell lymphomas, the sensitivity of Ig gene rearrangement was 91.18% (248/272), IgH and IgK gene rearrangement was 76.47% (208/272) and 75.00% (204/272), respectively, meanwhile the sensitivity of TCRγ rearrangement was 3.68% (10/272). In the 55 cases of mature T-cell lymphoma, the sensitivity of the detection of TCRγ was 76.36% (44/55), at the same time the sensitivity of Ig gene rearrangement was 14.55% (8/55), IgH and IgK gene rearrangement was 7.27% (4/55) and 12.73% (7/55), respectively. In 21 cases of extranodal NK/T cell lymphoma, nasal type, and 20 cases of reactive lymphoid hyperplasia, no gene rearrangement was found in the samples of IgH, IgK and TCR. The sensitivity of gene rearrangement in Ig/TCR in B and T-cell lymphoma was significantly different from that in the control group (P < 0.05).ConclusionThe Ig/TCR gene rearrangement of BIOMED-2 multiplex PCR strategy has important auxiliary value in the diagnosis of B/T-cell non-Hodgkin lymphoma respectively, however, a few B-cell lymphomas may company TCR gene rearrangement as well as a few T-cell lymphomas may accompany Ig gene rearrangement, it must be comprehensively judged with the combination of morphology, immunohistochemistry and clinical features.     

Agresywne chłoniaki z obwodowych limfocytów T

Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of relatively rare lymphoid malignancies. In Europe they account for approximately 15% of all lymphomas. Results of treatment of aggressive PTCL are poor and differ significantly from what has been achieved in recent years in the treatment of B-cell lymphomas. Currently, only patients with anaplastic large cell lymphoma ALK (+) have more than 50% chance of long-term survival. CHOP protocol should not be considered a standard of care, however, in the absence of alternatives it is used in clinical practice. Consolidation therapy with autologous haematopoietic stem cell transplantation (ASCT) improves response rate. This review summarizes treatment options for most common aggressive PTCL: anaplastic large cell lymphoma, angioimmunoblastic lymphoma, peripheral T-cell lymphoma NOS, NK/T-cell lymphoma, enteropathy associated lymphoma and hepatosplenic T-cell lymphoma.     

Usefulness of flow cytometry for differential diagnosis of precursor and peripheral T-cell and NK-cell lymphomas: analysis of 490 cases

Although various CD markers have been analyzed in T-cell and natural killer (NK)-cell lymphomas, the sensitivity and specificity of these phenotypic features have not been satisfactorily characterized. Flow cytometry (FCM) was used to determine the phenotypic pattern of 490 T/NK-cell lymphomas with the aid of a set of surface antigens (CD2, CD3, CD4, CD5, CD7, CD8, CD10, CD11c, CD16, CD19, CD20, CD25, CD30, CD34, and CD56). In data obtained from 319 patients, CD10 expression was detected in 57% of angioimmunoblastic T-cell lymphomas, CD30 in 93% of anaplastic large cell lymphomas, CD34 in 50% of lymphoblastic lymphomas, and CD56 in 100% of extranodal NK/T-cell lymphomas nasal type. A total of 92% of adult T-cell leukemia/lymphomas (ATLL) had expression of CD25 and downregulation of CD7. Of special interest is that 92 ATLL (50%) were CD4⁺CD7^-CD25⁺ phenotype while only four peripheral T-cell lymphoma unspecified (9%) and one (9%) cutaneous T-cell lymphoma had this phenotype. Phenotypic analysis using FCM was thus found to be useful for differential diagnosis of T-cell and NK-cell lymphomas.     

Comparison of lymphoid neoplasm classification. A blinded study between a community and an academic setting

The revised European-American classification of lymphoid neoplasms has been reported as reproducible among expert pathologists and feasible in a community setting. We evaluated the reproducibility of lymphoid neoplasm diagnoses between a community and an academic center. We subtyped 188 lymphoid neoplasms using revised European-American classification criteria. Clinical findings, histologic or cytologic preparations, paraffin-section immunostains, and flow cytometry data were reviewed as appropriate. Diagnoses were compared only after completion of the study. Lymphoma subtype was concordant for 167 (88.8%) of 188 cases. Discordant cases included 15 B-cell, 2 T-cell, and 4 Hodgkin lymphomas. For B-cell neoplasms, discordance was most often due to classifying diffuse large cell lymphoma as another aggressive subtype of lymphoma (n = 6), marginal zone lymphoma as another subtype (n = 4), or follicle center lymphoma grade II as grade III (n = 3). For Hodgkin disease, discordance was most often due to classifying nodular sclerosis as mixed cellularity type (n = 3). Comparison of community and academic center diagnoses demonstrated high concordance for most revised European-American classification subtypes. Some sources of discordance have been addressed in the new World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues.     

Distribution and ZAP-70 expression of WHO lymphoma categories in Shanxi, China: a review of 447 cases using a tissue microarray technique.

This study aims to assess the distribution of lymphoma subtypes in Shanxi, China, according to the World Health Organization (WHO) classification, and to compare the relative distribution with other areas of the world. H&E-stained tissue sections from the archives of the Shanxi Tumor Hospital, China, were reviewed and 447 cases with sufficient materials were selected for detailed study. A panel of antibodies and probes was assembled, including antibodies to ALK1, bcl-6, CDs 1alpha, 3, 4, 5, 7, 8, 10, 15, 20, 23, 30, 43, 56, 68, 79alpha, and 99, cyclin D1, EMA, kappa, lambda, LMP1, PAX5, TdT, Vs38C and ZAP70, plus EBER RNA probe by in situ hybridization. The 447 lymphoma cases, subtyped according to the WHO classification, were assembled in triplicate into 11 tissue microarrays and examined with the panel of markers described. Among the 447 cases, 385 (82.6%) were confirmed to be non-Hodgkin lymphomas (NHL) and 62 (13.9%) were Hodgkin lymphomas of classic type (CHL). Of the NHL cases, 68.6% were B-cell lymphomas and 30.6% T/NK-cell lymphomas. Histiocytic neoplasms accounted for only three cases (0.8%). Diffuse large B-cell lymphomas (DLBCL) were the most common subtype (35.1%), followed by peripheral T-cell lymphomas unspecified (PTun, 12.0%), extranodal marginal zone B-cell lymphomas (MALT lymphomas, 11.7%), follicular lymphomas (FL, 8.6%), T-lymphoblastic lymphomas (T-LBL, 7.0%), anaplastic large cell lymphomas (ALCL, 4.2%), B small lymphocytic lymphomas (B SLL, 3.6%), and mantle cell lymphomas (MCL, 2.6%). Of 263 B-cell neoplasms, 105 (39.9%) expressed immunoglobulin light chain, including 52 kappa and 53 lambda, detectable in paraffin sections. The incidence of DLBCL was similar to many Western countries and Asia. The frequency of FL was, however, much lower than the usual pattern in Western countries, although NK/T-cell lymphomas were more common (30.6%), similar to other countries in Asia, including Japan and Korea. With regard to markers of EBV infection, 8 of 385 (2.1%) NHL cases gave positive findings by both in situ hybridization (EBER RNA) and immunohistochemistry (LMP-1), whereas 24 (6.2%) expressed only the EBER and 12 (3.1%) expressed only LMP-1. EBV positivity was found in 24 of 119 (20.2%) T and NK cell lymphomas, in 20 of 263 (7.6%) B cell neoplasms, and in 37 of 62 (59.7%) CHLs. In CHLs there was complete concordance of results by both in situ hybridization (EBER RNA) and immunohistochemistry (LMP-1) procedures. ZAP70 was detected in most T cell-lineage disorders (61.4%) and also in a subset of B small lymphocytic lymphomas (50%). However, ZAP-70 was expressed in a minority of other types of B-cell lymphomas, including precursor B-cell acute lymphoblastic leukemia (25%), diffuse large B-cell lymphoma (26.7%), follicular lymphoma (15.2%), and lymphoplasmacytic lymphoma (9.1%). Immunohistochemical analysis represents an effective method for assessing ZAP-70 expression and reveals that a variety of B-cell malignant neoplasms express ZAP-70, albeit at low frequency.     

Clusterin expression in malignant lymphomas: a survey of 266 cases.

Clusterin expression has been reported to be characteristic of systemic anaplastic large cell lymphoma and usually negative in cutaneous anaplastic large cell lymphoma as well as other lymphoma types. We surveyed clusterin expression using immunohistochemical methods in 266 cases of non-Hodgkin's lymphoma and Hodgkin's disease to further assess the diagnostic utility of this marker. Clusterin immunostaining was observed in 40 of 49 (82%) systemic anaplastic large cell lymphomas and 12 of 29 (41%) cutaneous anaplastic large cell lymphomas. Clusterin also was expressed in 5 of 43 (12%) diffuse large B-cell lymphomas (4 of 5 CD30+), 1 of 14 (7%) peripheral T-cell lymphomas, 1 of 32 (3%) cases of nodular sclerosis Hodgkin's disease, and 1 case of mycosis fungoides in large cell transformation. Clusterin was negative in all other neoplasms assessed including follicular lymphoma of all grades (n = 24), mantle cell lymphoma (n = 13), marginal zone B-cell lymphoma (n = 12), precursor T-cell or B-cell lymphoblastic leukemia/lymphoma (n = 10), mixed cellularity Hodgkin's disease (n = 8), chronic lymphocytic leukemia/small lymphocytic lymphoma (n = 7), Burkitt lymphoma (n = 7), mycosis fungoides (n = 4), nodular lymphocyte predominant Hodgkin's disease (n = 3), lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia (n = 2), and plasmacytoma (n = 2). We conclude that clusterin is a marker of anaplastic large cell lymphoma and that addition of clusterin to antibody panels designed to distinguish systemic anaplastic large cell lymphoma from classical Hodgkin's disease is useful. However, clusterin is also positive in a substantial subset of cutaneous anaplastic large cell lymphomas, a smaller subset of diffuse large B-cell lymphomas, and rarely in cases of peripheral T-cell lymphoma and nodular sclerosis Hodgkin's disease.     

Primary natural killer/T-cell lymphomas of the oral cavity are aggressive neoplasms

Thirty-four cases of primary non-Hodgkin’s lymphoma of the oral cavity were investigated for their clinical findings, histopathological features, immunophenotypes and association with Epstein-Barr virus (EBV). Four cases (12%) were natural killer/T-cell lymphomas, 3 (9%) were T-cell lymphomas and 27 (79%) were B-cell lymphomas. Compared with T- and B-cell lymphomas, NK/T-cell lymphomas had a male predominance (M:F 4:0), and most presented as ulceration of the palate and/or maxillary gingiva. Histologically, the lesions showed diffuse infiltration of medium-sized or large lymphoid tumour cells. Angiocentricity and/or angioinvasion were found in all 4 cases. The immunophenotypes of the NK/T-cell lymphomas were CD3+, CD43+, CD45RO+, CD56+ and TIA-1+. EBV was detected in 2 NK/T-cell lymphomas by in situ hybridization (ISH) and polymerase chain reaction (PCR) methods, and was not detected in T- and B-cell lymphomas. The survival rate of patients with NK/T-cell lymphoma was zero, but the survival rates for patients with T-cell and B-cell lymphomas were 67% and 38%, respectively. It appears that NK/T-cell lymphomas of the oral cavity have a predilection for originating in the palate and maxillary gingiva and are aggressive neoplasms. EBV positivity might be associated with more aggressive behaviour. Received: 21 January 1999 / Accepted: 14 April 1999     

Hypermethylation of DAP-kinase gene CpG Island in malignant lymphoma with B-cell phenotype]

Death-associated protein-kinase(DAP-Kinase) is a pro-apoptotic serine/threonine kinase with a death domain, which is involved in apoptosis induced by interferon-gamma, tumor necrosis factor-alpha, and Fas ligand. Epigenetic down-regulation of DAP-Kinase gene expression by hypermethylation of its promoter region was reported in certain kinds of malignancies. Previous patho-epidemiological studies indicated that thyroid lymphoma(TL) evolves among active lymphoid cells in chronic lymphocytic thyroiditis(CLTH). With the use of methylation specific polymerase chain reaction, methylation status of DAP-Kinase CpG island was examined in thyroid lesions of 19 cases with TL and 9 with CLTH. Frequency of methylation was higher in TL cases(16 of 19, 84.2%) than in CLTH cases(2 of 9, 22.2%) (p < 0.01). DNA extracted from peripheral blood leukocytes from TL and CLTH cases never showed methylation, indicating that the methylation occurred somatically in lesional lymphocytes in the thyroid. We also examined the methylation status of DAP-kinase gene in 16 cases of T-cell malignancies including eight adult T-cell leukemia/lymphoma and 24 NK/T-cell, 34 B-cell, and two immunophenotypically undetermined lymphomas. Frequency of methylation was higher in B-cell(27 of 34, 79.4%) than in T-cell malignancies(eight of 16, 50%) (p < 0.05). Fifteen of 24(62.5%) NK/T-cell lymphomas showed DNA methylation. Hematopoietic cell lines with a methylated gene were resistant to apoptosis. Treatment of the cells with a demethylating agent restored apoptotic cell death in one B-cell lymphoma cell line with DNA methylation. Our results suggested that suppression of DAP-Kinase expression by DNA methylation might play a role in the development of B-cell malignancies.     

Characterization of Non-Hodgkin''s Lymphomas Using Multiple Cell Markers: Immunologic, Morphologic, and Cytochemical Studies of 72 Cases

Tissues from 72 cases (87 specimens) of various non-Hodgkin's lymphomas were analyzed for cell markers using multiple techniques. Cell suspensions were evaluated for E, EAC, and IgGEA rosette forming cells; Fc receptor cells; and surface immunoglobulin bearing cells. Cryostat section studies topographically defined EAC binding cells. Cytochemical determinations and immunoperoxidase methods for detection of intracellular immunoglobulin and lysozyme complemented other techniques in evaluating infiltrates containing large neoplastic cells. B-cell malignancies comprised 58 cases (80%) of this series and included well and moderately well differentiated lymphocytic lymphomas (10/10); nodular (23/23) and diffuse (10/18) poorly differentiated lymphocytic lymphomas; and lymphomas of mixed lymphocytic-“histiocytic” (3/3), “undifferentiated” (3/3), and “histiocytic” (9/13) types. Nodular lymphomas were characterized as B-cell neoplasms but also revealed a prominent population of T lymphocytes (39 ± 12%). Alkaline phosphatase activity, a cytochemical marker for lymphoid cells of follicular cuffs, was most consistently observed in B-cell lymphomas of moderately well differentiated lymphocytic type (4/6 cases). In some diffuse lymphomas, cryostat section studies (EAC rosettes) suggested a pre-existing nodular proliferation. One unusual B-cell lymphoma of large cell type exhibited IgGEA rosette formation and a strong receptor for the Fc portion of IgG. Ten lymphomas (14%) were of T-cell type and were represented by cases of diffuse poorly differentiated lymphocytic lymphoma (5/18, including 3 lymphoblastic lymphomas), Sézary syndrome (1), mycosis fungoides (1), and a cytologically distinctive large cell (“histiocytic”) lymphoma (3/13). Acid phosphatase activity was a consistent marker for the T-cell malignancies, some of which also revealed α-naphthyl butyrate esterase activity. No true histiocytic lymphomas were detected. Three cases of diffuse poorly differentiated lymphocytic lymphoma and one “histiocytic” lymphoma were null.     

Paraffin-immunohistochemical analysis of 226 non-Hodgkin's malignant lymphomas in the endemic area of human T-cell leukemia virus type 1

A study was conducted to evaluate the usefulness of paraffin-immunohistochemistry for histopathological classification of non-Hodgkin's malignant lymphomas (NHML). the phenotypes of lymphoma cells and other cells were examined using 11 monoclonal and 3 polyclonal antibodies by the ABC method on paraffin-embedded tissue sections of 226 cases of NHML, comprising 94 B-cell lymphomas (B-ML) and 132 T-cell lymphomas (T-ML). In 219 NHML cases (96.8%), lymphoma cells reacted with more than one of these antibodies. A set of MB-1, Mx-pan B, L26, LN-1, LN-2 and anti-immunoglobulin light chain antibodies characterized each subtype of B-MLs, categorized according to the Kiel classification. Mantle-zone lymphoma (MzML) was added as one subtype. L26 stained the largest number of B-MLs (82.8%). B-cell chronic lymphocytic leukemia (B-CLL) was labeled most frequently by MB-1. MzML was characterized by reactivity of lymphoma cells with LN-2 and by the appearance of monoclonal immunoglobulin light chain along the cell membrane. Follicle center cell lymphomas were stained by LN-1 and LN-2, although a small number of proliferating cells were labeled by LN-1 in B-CLL, MzML and the immunocytoma lymphoplasmacytic/cytoid variant. MT-1 and/or UCHL-1 showed various degrees of reactivity with the cell membranes of lymphoma cells in 94.8% of T-MLs. Among the T-cell pleomorphic lymphomas of Suchi and Lennert, the adult T-cell leukemia/lymphoma type, defined by stippled heterochromatin distribution and peculiar huge cells, reacted selectively (p less than 0.05) with anti-phosphokinase C antibody. Anaplastic large cell T-ML reacted with a set of Ber H2, LN-2 and Leu M1. In T-zone lymphomas without hyperplastic follicles, angioimmunoblastic lymphadenopathy with dysproteinemia-type T-ML, lymphoepithelioid cell lymphomas and some pleomorphic lymphomas comprising clear large lymphoma cells, there were many intermingling B cells, and their constitution varied. In some lymphoblastic lymphomas of both the T cell and B-cell type, phenotypes of T cells and B cells were expressed. Consequently, it was shown that paraffin immunohistochemistry was useful for the practical histopathological diagnosis of NHML even in the area where human T-cell leukemia virus type 1 is endemic.