Practical Utility of the Revised European-American Classification of Lymphoid Neoplasms for Japanese Non-Hodgkin's Lymphomas

A clinicopathological study of 515 non-Hodgkin's lymphoma (NHL) cases was performed using the revised European-American classification of lymphoid neoplasms (REAL classification) in an HTLV1-nonendemic area of Japan. The following characteristics were revealed: 1) frequency of extranodal lymphomas was high (59%) with 79% B-cell lymphomas in this series, while the overall ratio of B:T/NK lineage was 3.7:1; 2) the most common type was the diffuse large B-cell lymphoma (46%), follicle center lymphomas occurred at an incidence lower (15%) than that in European and American populations, and marginal zone B-cell lymphomas accounted for as much as 12%; 3) peripheral T-cell lymphomas were common (19%), with the unspecified type predominant (11%), while adult T-cell lymphomas were present at a level equivalent to that among European and American patients (1%). Clear segregation of survival curves was rated according to cell lineage and B-cell lymphomas had a better prognosis than T/NK-cell lymphomas. Furthermore, new subtypes in the REAL classification, such as marginal zone B-cell and mantle cell lymphomas, exhibited distinct curves. Taken altogether, the REAL classification demonstrated advantages for assessment of Japanese NHL cases.     

Practical utility of the revised European-American classification of lymphoid neoplasms for Japanese non-Hodgkin's lymphomas.

A clinicopathological study of 515 non-Hodgkin's lymphoma (NHL) cases was performed using the revised European-American classification of lymphoid neoplasms (REAL classification) in an HTLV1-nonendemic area of Japan. The following characteristics were revealed: 1) frequency of extranodal lymphomas was high (59%) with 79% B-cell lymphomas in this series, while the overall ratio of B:T/NK lineage was 3.7:1; 2) the most common type was the diffuse large B-cell lymphoma (46%), follicle center lymphomas occurred at an incidence lower (15%) than that in European and American populations, and marginal zone B-cell lymphomas accounted for as much as 12%; 3) peripheral T-cell lymphomas were common (19%), with the unspecified type predominant (11%), while adult T-cell lymphomas were present at a level equivalent to that among European and American patients (1%). Clear segregation of survival curves was rated according to cell lineage and B-cell lymphomas had a better prognosis than T / NK-cell lymphomas. Furthermore, new subtypes in the REAL classification, such as marginal zone B-cell and mantle cell lymphomas, exhibited distinct curves. Taken altogether, the REAL classification demonstrated advantages for assessment of Japanese NHL cases.     

Malignant lymphoma in southern Taiwan according to the revised European-American classification of lymphoid neoplasms

BACKGROUND: The purpose of the current study was to determine the distribution and relative frequency of each subtype of malignant lymphoma in southern Taiwan according to the revised European-American classification of lymphoid neoplasms (REAL). METHODS: The pathology files of a regional hospital in southern Taiwan for 1989-1998 were searched for malignant lymphoma, lymphoproliferative disorder, and Hodgkin disease (HD). The results of light microscopy, immunohistochemistry, and in situ hybridization for Epstein-Barr virus-encoded RNA (EBER) were correlated with clinical findings, and all cases were classified according to REAL. RESULTS: A total of 205 cases were analyzed retrospectively. There were 197 cases (96.1%) of non-Hodgkin lymphoma (NHL) and 8 cases (3. 9%) of HD. Among the 197 NHL cases, 161 (81.7%) were of B-cell lineage and 36 (18.3%) were of T-/natural killer cell lineage. Diffuse large B-cell lymphoma, extranodal marginal zone lymphoma, and follicular lymphoma were the most common B-cell subtypes and represented 47.2%, 19.3%, and 6.1%, respectively, of all NHL cases. Among the 36 cases of T-/natural killer cell lineage, unspecified peripheral T-cell lymphoma (8.6%), T-/natural killer cell lymphoma (angiocentric lymphoma) (4.1%), and anaplastic large cell lymphoma (3.6%) were the most common subtypes. Seven of eight T-/natural killer cell lymphoma cases were positive for EBER. The eight cases of HD were classified as lymphocyte-rich classic (two cases), nodular sclerosis (two cases), and mixed cellularity (four cases) subtypes. Three of these eight cases were positive for EBER. CONCLUSIONS: To the authors' knowledge this study is the first in Taiwan using the REAL classification and it again confirms the different geographic distribution of the various subtypes of malignant lymphoma. The frequency of T-/natural killer cell lineage NHL in Taiwan is higher than that in Western countries but not as high as reported previously.     

Non-Hodgkin's lymphoma of the ocular adnexa

This study investigates the relationship between the clinical features of lymphoma in the ocular adnexal region and the revised European and American lymphoma (REAL) classification. Specimens from 41 patients with ocular adnexal lymphoproliferative disease were reassessed pathologically using the REAL classification. Thirty-two patients with primary non-Hodgkin's lymphomas (NHL) were included in the study, almost all of them having been treated with radiotherapy with or without chemotherapy. Seven of the 32 patients with NHL showed distant recurrence after treatment: 3 out of 26 with extranodal marginal zone B-cell lymphoma, and 4 with other types of NHL. Although the three patients with recurrent marginal zone B-cell lymphomas all survived, other patients with recurrent lymphomas died of disease. The REAL classification provides a good indication of tumor control probability and survival of patients with ocular adnexal NHL. Radiation therapy is an effective treatment modality for extranodal marginal zone B-cell lymphoma of the ocular adnexa.     

Pathology review for paediatric non-Hodgkin's lymphoma patients in Japan; a report from the Japan association of childhood leukaemia study (JACLS)

A central pathology review system with an immunophenotyping laboratory was established in Japan to support the clinical trial, the Japan Association of Childhood Leukaemia Study (JACLS) NHL-98, for patients with paediatric non-Hodgkin's lymphoma (NHL). Pathology samples from 155 clinically-suspected NHL cases were evaluated centrally initially using the Revised European-American Lymphoma (REAL) classification in a rapid review (within 2 weeks after surgery/biopsy) and then later at the consensus review (once a year). The samples were subsequently re-classified according to the new World Health Organisation (WHO) classification. After the pathology review, 96 (62%) patients were eligible for the study, and 58 of them (60%) had extra-nodal primaries. These NHL cases included B-cell lymphomas (precursor B-cell, 11; Burkitt, 18; diffuse large B-cell, 18; not otherwise specified, 3) and T/Natural Killer (NK)-cell lymphomas (precursor T-cell, 23; anaplastic large cell, 20; others, 3). There was excellent concordance in making the diagnoses (95/96, 99%) and typing (93/96, 97%) of NHL between the rapid and consensus reviews. Five cases, initially diagnosed as diffuse large B-cell lymphoma by the review, were re-classified as Burkitt lymphoma according to the immunocytochemical criteria by the WHO classification. A total of 59 (38%) cases were excluded from the study: they were Hodgkin lymphoma (7), leukaemias (11), reactive lymphoid hyperplasia (20), necrotizing lymphadenitis (7), no consensus diagnosis (1), insufficient materials (2), and others (11). This is the first report of the central pathology review from the paediatric NHL group study in Japan. Because various diseases, either neoplastic or reactive, mimicked NHL, clinically and histopathologically, the central pathology review system was critical and essential for patient enrollment and protocol assignment in our clinical trial. Through the two-step review system, highly reliable data were generated to support this study.     

A review of childhood cases of malignant lymphoma in Osaka, Japan

Fifty-one cases of malignant lymphomas in patients under 20 years of age have been reviewed in Osaka, Japan. The breakdown of these cases revealed 6 cases (11.8%) of Hodgkin's disease (HD) and 45 cases (88.2%) of a non-Hodgkin's lymphoma (NHL). Both the HD and NHL cases were determined by using the Rye classification, as well as the Rappaport, Kiel, and LSG classifications, respectively. The results have shown that (1) the incidence of HD in childhood is the same as that seen in the adult in Japan; (2) that a NHL of the nodular type is rare in Japan as it is in Western countries; (3) that any significant differences were not present in the distribution of each histologic subtype in the cases of a NHL among Japan and Western countries, and that the lymphoblastic type was the most common. From this study it is concluded that geographical differences were not a factor in comparing cases of childhood malignant lymphomas in Japan and Western countries.     

Evaluation and management of the “New” lymphoma entities: Mantle cell lymphoma, lymphoma of mucosa-associated lymphoid tissue, anaplastic large-cell lymphoma, and primary mediastinal B-cell lymphoma

Non-Hodgkin's lymphomas (NHL) represent a major health problem worldwide, and incidence has been on the rise continuously for the last few decades. It is estimated that approximately 55,000 new cases of NHL will be diagnosed in the United States in 1998 and that slightly fewer than 25,000 patients will die of treatment failure or recurrent disease. The rising incidence of NHL is related not only to the acquired immunodeficiency syndrome epidemic but to also a steady increase in the number of cases diagnosed in older patients without immunosuppression. The new pathologic classification of NHL (revised European-American lymphoma classification, REAL) developed by the International Lymphoma Study Group (ILSG) is already resulting in more accurate disease-specific epidemiologic and clinical investigations. These studies have brought a new awareness of the existence and the relative prevalence of discrete NHL subtypes that appear to predominate among patients in different populations according to age, sex, geographic distribution, and predisposing conditions. This developing database has also the potential to result in the discovery of specific environmental causes, predisposing genetic factors, and therapeutic approaches. Some of the entities defined in the REAL classification, such as follicular lymphomas, diffuse B large-cell lymphomas, and T-cell lymphoblastic lymphomas, were already well described in the older classification systems (Kiel and Working Formulation). Others, such as mantle cell lymphoma, (MCL) anaplastic large-cell lymphoma (ALCL), lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), and primary mediastinal B-cell lymphoma (PMBCL) are relatively new members of the family, and accurate data on their clinicopathologic features and natural histories have only recently begun to emerge.This review presents in detail the most recent data on the clinical presentation of, diagnostic evaluation of, and treatment options for the most common of the new NHL entities: MCL, MALT lymphoma, CD30⁺ (Ki-1⁺) ALCL, and PMBCL. These four entities combined represent approximately 20% of all cases of NHL and exemplify well the broad clinicopathologic spectrum of NHL and the diagnostic and therapeutic challenges facing those who care for patients affected by these conditions.     

Head-and-neck stages I and II extranodal non-Hodgkin's lymphomas: real classification and selection for treatment modality

PURPOSE: We re-evaluated histopathological specimens of head and neck early-stage extranodal non-Hodgkin's lymphoma (NHL) using the revised European and American lymphoma (REAL) classification, and also investigated the relationship between the clinical characteristics and histopathological classification in an attempt to evaluate the usefulness of this new classification system in selecting treatment modalities. MATERIALS AND METHODS: Between 1979 and 1995, 117 patients with histologically confirmed stages I and II NHL of head-and-neck extranodal regions were treated. Of these patients, 110 specimens were available for re-evaluation. Sixty-four patients had Stage I, and 46 had Stage II diseases. All but 3 had received radiation therapy, and 59 patients were also treated with intensive combination chemotherapy. RESULTS: There were 32 extranodal marginal-zone B-cell lymphomas, 57 diffuse large B-cell lymphomas, 11 peripheral T/NK-cell lymphomas, and 10 others. The 5- and 10-year cause-specific survival rates for all patients were 72% and 62%, respectively. Patients with extranodal marginal-zone B-cell lymphoma or other low-grade B-cell lymphomas demonstrated higher survival rates than patients with other lymphomas. Patients with peripheral T/NK lymphomas showed the lowest survival rate. CONCLUSION: The REAL classification accurately indicated the prognosis of patients with NHL. These results suggest that appropriate treatment modalities can be selected using this classification.     

Outcome of patients with non-Hodgkin's lymphoma of the stomach after gastrectomy: clinicopathologic study and reclassification according to the revised European-American lymphoma classification

Background. The best treatment for patients with non-Hodgkin's lymphoma (NHL) of the stomach is still uncertain. The revised European-American lymphoma (REAL) classification has helped to define new, potentially more appropriate classification schemes for gastric lymphomas. Methods. Fifty-one resected gastric lymphomas were reclassified according to the REAL classification, and the efficacy of multimodal treatment was examined retrospectively. The principal treatment plan consisted of: (1) surgical resection of the stomach with lymph node dissection, followed by (2) systemic chemotherapy, mainly using the cyclophosphamide/doxorubicin/vincristine/prednisone (CHOP) regimen. Results. According to the Ann Arbor classification, 27 patients had stage IE, 19 had stage IIE, and 5 had stage IV NHL. Using the REAL classification, we diagnosed diffuse large B-cell lymphoma (DLBL) in 23 patients, marginal zone B-cell (low-grade mucosa-associated lymphoid tissue [MALT]-type) lymphoma in 22, follicle center lymphoma in 4, mantle cell lymphoma in 1, and peripheral T-cell lymphoma in 1 patient. Nine of the 51 patients relapsed, and 8 patients with DLBL died of cancer. Survival rates at 5 years after surgery were 96.0% for stage IE, 83.3% for stage IIE, and 87.0% for all patients. Univariate analysis indicated that the tumor histology (according to the REAL classification), depth of invasion, degree of nodal involvement, Ann Arbor staging, and chemotherapy had an impact on patient outcome (P = 0.0018; P = 0.0002; P = 0.0308; P = 0.0016, and P = 0.0118, respectively). Conclusions. These data reveal that gastric NHL, especially of the low-grade MALT-type, often remains localized and has a good prognosis after surgery. The REAL classification was useful for classifying new categories of NHL, including the MALT-type, in the clinical setting, and for determining the optimal treatment modality for gastric NHL. Received: December 11, 2000 / Accepted: July 18, 2001     

Pattern of Malignant Lymphoma in the United Arab Emirates - A Histopathologic and Immunologic Study in 208 Native Patients

The aim of this study was to analyze the distribution of the various pathologic types of lymphoma in a native Arab population of the United Arab Emirates (UAE). Two hundred and eight patients with malignant lymphoma diagnosed over a 12-year period (1988?1999) were retrospectively studied morphologically and immunohistochemically with a panel of monoclonal antibodies and classified according to the revised European?American classification of lymphoid neoplasms (REAL). Of the 208 patients in the study, 41% had Hodgkin's disease (HD) and 59% had non-Hodgkin's lymphoma (NHL). The distribution of HD showed a predominance of nodular sclerosis and mixed cellularity types. Among NHLs, the most frequent type was diffuse large B cell (59% of all NHLs) followed by the Burkitt's type (13%). The proportion of primary extranodal NHL was 29%. Immunologically, the percentages of NHL with B-cell and T-cell phenotypes were 83 and 11, respectively. When the International Working Formulation was used, 34% of NHLs were classified as high grade, 59% as intermediate grade and only 7% as low-grade lymphomas.     

Distribution and prognosis of WHO lymphoma subtypes in Taiwan reveals a low incidence of germinal-center derived tumors

To assess the distribution of lymphomas in Taiwan according to the WHO (World Health Organization) classification, 175 recently diagnosed cases of malignant lymphomas were studied and the clinicopathologic data were analyzed. B-cell lymphomas accounted for 57.1% of cases, T-cell lymphomas 38.9%, and Hodgkin's lymphoma 4%. Extranodal lymphomas predominated (55.4%). The most common subtype of B-cell lymphoma was diffuse large B-cell lymphoma (33.1%). All tumor types believed to be derived from germinal center (GC) B-cells including follicular lymphoma (4.6%), Burkitt lymphoma (1.7%), Hodgkin lymphoma (4.0%), and GC-like diffuse large B-cell lymphoma (as defined by combined expression of bcl-6 and CD10) were rather uncommon as compared to frequencies seen in series from Western countries. The common T-cell lymphomas included nasal and extranasal NK/T cell lymphoma (7.4%), mycosis fungoides (7.4%), and unspecified peripheral T-cell lymphoma (6.9%). Adult T-cell leukemia/lymphoma was very uncommon and accounts for only 0.6%. The proportional increase in T-cell lymphomas that were unrelated to type I human T-cell lymphotropic virus (HTLV-1) may be linked to differential Epstein-Barr virus (EBV) oncogenesis. The survival data revealed that mantle cell lymphoma, NK/T-cell lymphoma, unspecified peripheral T-cell lymphoma, and subcutaneous panniculitis-like T-cell lymphoma had an aggressive course. Our results confirm the utility of the WHO classification scheme for prognostic stratification and further highlight the distinctive distribution pattern of malignant lymphoma in Taiwan including the higher relative incidence of T cell lymphomas and the rarity of germinal center-derived B-cell tumors.     

A pathologic study of childhood lymphoma in Taiwan with special reference to peripheral T-cell lymphoma and the association with Epstein-Barr viral infection.

The authors retrospectively reviewed the clinicopathologic and immunologic features of 65 consecutive cases of childhood lymphoma reported between 1980 and 1989. Southern blot hybridization was also performed in 23 cases to study their association with Epstein-Barr virus (EBV) and human T-cell leukemia virus type 1 (HTLV-1). The 65 cases included 56 non-Hodgkin's lymphoma (NHL) (86%) and 9 Hodgkin's disease (HD) (14%). The NHL could be classified into the following groups: Group I, small noncleaved cell lymphoma (20 cases); Group II, lymphoblastic lymphoma (17 cases); Group III, large cell lymphoma (17 cases); and miscellaneous (2 cases). There was no follicular lymphoma case. Immunohistochemical study on paraffin sections and/or frozen specimens in 47 cases of NHL showed that all the Group I cases belonged to B-cell neoplasm (17 of 17 cases); most of the Group II cases belonged to T-cell neoplasm (9 of 14 cases); and most of the Group III cases were peripheral T-cell lymphoma (PTL) (8 of 16 cases), including 2 cases of Ki-1 lymphoma. The majority of childhood NHL belonged to high-grade malignancy with an aggressive clinical course (median survival time, 8 months). The EBV DNA could be detected from the tumor tissues in 4 of 6 PTL, but in none of the remaining 19 cases of NHL including 6 Burkitt's type lymphomas. HTLV-1 proviral genome was not detected in all specimens examined. The authors concluded that the distribution pattern and clinicopathologic feature of childhood lymphoma in Taiwan are comparable to that in Japan and western countries. The frequent association of EBV with aggressive PTL was unique and deserves additional investigation.     

Clinico-pathological features of malignant lymphomas in 294 Hong Kong Chinese patients, retrospective study covering an eight-year period

The clinical records and histological material from 294 adult Chinese patients with malignant lymphoma were examined. These patients were first seen at the Queen Mary Hospital, Hong Kong, during the 8-year period 1975-82. There were 27 patients (9.2%) with Hodgkin's disease (HD) and 267 with non-Hodgkin's lymphoma (NHL). The median age at presentation was younger for HD (45 years) and the male: female ratio was higher (2:1) than the corresponding figures for NHL of 51 years and 1.4:1. In 76 patients (28.5% of NHL), the disease was thought to have originated in an extra-nodal site, 48 of these cases being gastrointestinal lymphomas. It was possible to reclassify 234 NHL according to the Rappaport and Kiel classifications, and the Working Formulation (WF) proposed by the US National Cancer Institute Study; for HD, the Rye classification was used in 26 cases where suitable material was available. Nodular/follicular lymphomas made up 17.1% of nodal NHL and 5.3% of extra-nodal NHL. The "histiocytic" (Rappaport) or large-cell (WF) subtype was the commonest amongst diffuse NHL. There were only four cases of Burkitt's lymphoma. For HD, the nodular sclerosing subtype was commonest in females (5 out of 8 cases) and for males, the commonest was mixed cellularity (10 out of 18 cases). Of patients with nodal NHL 64.7%, presented with Stage IV disease. For HD, there were about equal numbers of patients presenting with Stage II and Stage IV disease (10 and 9 respectively). The low incidence of Hodgkin's disease and of follicular lymphomas is comparable to figures from other "oriental" countries such as Japan.     

Non-Hodgkin lymphoma in Chile: a review of 207 consecutive adult cases by a panel of five expert hematopathologists

The distribution of subtypes of non-Hodgkin lymphoma (NHL) in Latin America is not well known. This Chilean study included 207 consecutive cases of NHL diagnosed at five cancer centers in the capital, Santiago, and one center in Vi?a del Mar. All cases were reviewed and classified independently by five expert hematopathologists according to the 2001 World Health Organization classification of NHL. A consensus diagnosis of NHL was reached in 195 of the 207 cases (94%). B-cell lymphomas constituted 88% of NHL, and diffuse large B-cell lymphoma (DLBCL, 38.5%) and follicular lymphoma (25.1%) were the most common subtypes. There was a high frequency of marginal zone B-cell lymphoma (10.3%), as well as of extranodal natural killer (NK)/T-cell lymphoma, nasal type (2.6%) and adult T-cell leukemia/lymphoma (0.5%). Extranodal presentation was seen in 74 of the 195 cases (38%) and the most common extranodal presentation was in the stomach (37.6%). The most common gastric lymphoma was DLBCL (54.5%) followed by mucosa-associated lymphoid tissue (MALT) lymphoma (41%). Overall, the frequency of NHL subtypes in Chile is between that reported in Western and Eastern countries, which is probably a reflection of the admixture of ethnicities as well as the environment and socioeconomic status of its population.     

Peripheral T-cell lymphoma

Since the discovery of human T-cell leukemia virus type 1 (HTLV-1) in patients with adult T-cell leukemia/lymphoma (ATLL), malignant neoplasms of mature (peripheral) T lymphocytes have attracted a great deal of attention. This type of neoplasm is more common in Japan than in Western countries, and may show distinct clinical pictures such as hypergammaglobulinemia, hypercalcemia, etc. T-cell lymphomas are more prone than B-cell lymphomas to become leukemic. Because of a marked intermingling of reactive cells (histiocytes, eosinophils, etc.), the histologic diagnosis of T-cell lymphoma is often difficult. Proliferation pattern and cellular size do not correlate with prognosis as in B-cell lymphoma. Since T-cell lymphomas often manifest with several distinct clinicopathologic settings, their categorization should be based on several parameters, such as the presence or absence of ATLL-associated antigen in serum, histology, phenotype of the neoplastic cell, and clinical features. Since a classification for T-cell lymphomas has not been established, a further multi-disciplinary approach is necessary for a better understanding of this interesting neoplasm.     

Prognostic significance of the immunophenotype versus the International Prognostic Index in aggressive non-Hodgkin's lymphoma

The International Prognostic Index (IPI) is currently the most widely accepted prognostic factor system for patients with aggressive non-Hodgkin's lymphoma (NHL). However, in constructing the model, the immunophenotype of the disease was not used as an independent variable. The purpose of the present study was to assess and compare the prognostic significance of the immunophenotype (B-cell vs. T-cell) of aggressive NHL with other well-established prognostic determinants, in particular the IPI. Between January 1995 and December 2000, a retrospective analysis was conducted of clinical and pathological data on 181 patients aged = 15 years who had been newly diagnosed with aggressive NHL. All pathology slides were reviewed and defined according to the Revised European-American Lymphoma classification. Forty-one patients (23%) had T-cell lymphoma and 140 patients (77%) had B-cell lymphoma. Diffuse large B-cell lymphoma and unspecified peripheral T-cell lymphoma were the 2 most common entities, comprising 63% and 14% of patients, respectively. Most of the pretreatment characteristics, including IPI risk groups, were not significantly different between B-cell and T-cell lymphomas. The rates of complete remission (71% vs. 54%, P = 0.038) and progressive disease (39% vs. 63%, P = 0.023) significantly favored patients with B-cell lymphoma. With a median follow-up time of 31 months (range, 10-81 months), the 5-year overall survival (49% vs. 27%; P < 0.001) and event-free survival (35% vs. 10%; P < 0.001) were significantly better in B-cell lymphoma. The 5-year disease-free survival was also in favor of the B-cell group (48% vs. 21%; P = 0.086). Patients with T-cell lymphoma yielded inferior survival in all IPI risk groups. Multivariate analysis revealed T-cell lymphoma as the most significant factor associated with short overall survival (relative risk [RR], 3.4; 95% CI, 1.9-5.9) and event-free survival (RR 2.7, 95% CI, 1.7-4.3). When a second multivariate analysis was done using IPI (age, stage, performance status, number of extranodal sites, and serum lactate dehydrogenase) as one independent variable, T-cell phenotype remained the strongest factor affecting the survival of patients (P < 0.001). T-cell lymphoma is an independent prognostic factor, the significance of which is at least comparable to the IPI for patients with aggressive NHL.     

Use of the World Health Organization (WHO) classification of non-Hodgkin's lymphoma in Mumbai, India: a review of 200 consecutive cases by a panel of five expert hematopathologists

This study aims to answer the question whether the World Health Organization (WHO) classification of non-Hodgkin's lymphoma (NHL) can be practised to international standards at the Lymphoma Registry (LR) established at the Tata Memorial Hospital, Mumbai, India. Furthermore, the study aims to identify differences in the distribution of NHL subtypes at this LR (likely to be representative of India) as compared to the rest of the world. A panel of 5 expert hematopathologists from the NHL Classification Project reviewed 200 consecutive NHL cases at the LR in January of 2001. These cases were accrued during August and September, 2000. On all cases, hematoxylin and eosin stains and appropriate immunostains were available for review. The diagnosis made by the host pathologist at the LR (KNN) and the initial diagnosis made by each of the expert hematopathologists was compared with the consensus diagnosis. A consensus diagnosis was made by the 5 experts in 197 cases. The agreement of the host pathologist with the consensus diagnosis was 82% and the agreement of the individual experts with the consensus diagnosis varied from 76-88% (mean 82%). According to the consensus diagnosis, 80% of NHLs were of B-cell type, 18% were of T-cell type, and the immunophenotype could not be determined in the remaining 2% of cases. In conclusion, the WHO classification of NHL was properly utilized at the Lymphoma Registry, Mumbai, India, and geographic differences were noted in the distribution of NHL subtypes at the LR as compared to the rest of the world. Precursor T lymphoblastic leukemia/lymphoma was more common in India (7%) than the rest of the world (1-4%), and indolent B-cell NHLs (29%) were less common than in the West. As compared to China and Japan, peripheral T-cell lymphoma (4.6%), extranodal NK/T cell lymphoma, nasal type (0.5%) and extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-lymphoma) (2.6%) were less common, but follicular lymphoma (15%) and chronic lymphocytic leukemia/small lymphocytic lymphoma (5%) were more common. This suggests that the distribution of the B-cell and T-cell lymphomas in the Indian population, except for lymphoblastic lymphoma, lies in between the Western world (mainly Caucasian) and the Orientals.     

Distribution and clinicopathologic characteristics of non-Hodgkin's lymphoma in India: a study of 935 cases using WHO classification of lymphoid neoplasms (2000)

The frequency of various subtypes of non-Hodgkin's lymphoma (NHL) differs in various regions worldwide. We studied distribution of various subtypes of NHL by using WHO classification of lymphoid neoplasms (2000), immunophenotyping and clinicopathologic characteristics of various histologic subtypes in 935 cases. B- and T-cell NHL constituted 79.3% and 18.8% of cases. Diffuse large B-cell lymphoma (DLBL) was the most common subtype (50.2%). A lower frequency of follicular lymphoma, marginal zone lymphoma and mantle cell lymphoma (MCL) was noted compared to that observed in the developed countries, whereas a lower frequency of peripheral T-cell lymphoma - not otherwise specified (PTCL-NOS) and extranodal NK/T-cell lymphoma was seen compared to that in the other Asian countries. A higher frequency of DLBL and precursor T-lymphoblastic leukemia/lymphoma was noted. Extranodal and bone marrow involvement in MCL and PTCL-NOS was less frequent. Anaplastic variant of DLBL was noted in 21.5% of all DLBLs. Null/T-cell anaplastic large cell lymphoma presented in the older age.     

Malignant lymphomas of bone in Japan

Thirty-four cases of primary non-Hodgkin's lymphoma (NHL) of bone collected from hospitals in Japan were histologically and immunohistologically reviewed, and the results were compared with those in Western countries. There were no remarkable differences in age, sex, and the distribution of bone tumors between Japanese and Western cases. Sixteen cases (47%) diagnosed previously as "reticulum cell sarcoma" were reclassified as diffuse NHL of large cell (seven cases), mixed type (four cases), immunoblastic type (three cases), clear cell type (one case), and multilobated type (one case). The cases with small lymphocytic type with plasmacytoid features (lymphoplasmacytic type) were more common in Japan (35% of our cases) than in Western countries. The distribution of histologic subtypes, except for lymphoplasmacytic and T-cell lymphomas, in the current cases was similar to that in Western countries. However, immunohistochemistry showed that Japanese cases contained a much higher frequency of T-cell lymphoma (10% of all cases) than Western cases. Histologic grade according to the Working Formulation correlated well with clinical stage. There may be a tendency towards better prognosis with lower grade tumors, but this was not statistically significant.