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EXCELLENT OUTCOMES OF SUBCUTANEOUS PANNICULITIS-LIKE T-CELL LYMPHOMA TREATED WITH CYCLOSPORIN-BASED REGIMEN, A MULTICENTER RETROSPECTIVE STUDY IN THAILAND The patient demographic data, treatment regimens which divided into conventional chemotherapy or immunosuppressive agents, and treatment outcomes were retrieved from the Thai lymphoma registry database. B Background: b Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cytotoxic T-cell lymphoma, characterized by primary cutaneous tissue involvement mimicking inflammatory panniculitis. [Extracted from the article]

Introduction: Liver iron overload is common in patients with thalassemia. In patients with beta-thalassemia, the correlation between serum ferritin and liver iron concentration is well established. The correlation between serum ferritin levels and liver iron concentrations in patients with alpha-thalassemia remains limited., Methods: This is a cross-sectional study in patients with alpha-thalassemia aged ≥ 18 years old at Srinagarind Hospital, Khon Kaen University, Thailand. Liver iron concentration (LIC) was evaluated by the MRI-T2* technique. Linear logistic regression analysis was used to determine the correlation between serum ferritin levels and liver iron concentrations., Results: One hundred and thirty-one of the MRI-T2* measurements from 65 patients with alpha-thalassemia were evaluated. Patients with non-deletional alpha-thalassemia had higher LIC compared to patients with deletional alpha-thalassemia. The serum ferritin levels were relatively low at the same levels of LIC in patients with non-deletional alpha-thalassemia compared to deletional alpha-thalassemia ., Conclusions: The correlation of serum ferritin levels and LIC was modest and different among alpha-thalassemia genotypes. A different serum ferritin threshold is needed to guide iron chelation therapy in patients with alpha-thalassemia. Evaluation of liver iron concentration is necessary for patients with alpha-thalassemia, especially in patients with non-deletional alpha-thalassemia.

The incidence and outcomes of aplastic anemia (AA) in Asia remain limited. This study aimed to explore the incidence and outcomes of patients with adult AA across the country of Thailand. This is a prospective multi-center nationwide population-based observational study of AA patients aged at least 15 years old, diagnosed from August 2014 to July 2016, with a longitudinal follow-up period over 2 years. There were 348 newly diagnosed adult AA patients during the enrollment period, giving an annual incidence of 4.6 per million. The incidence of severe (SAA) and very severe aplastic anemia (VSAA) (3.8 per million) was higher than non-severe AA (NSAA, 0.8 per million). The peak incidence was observed in the patients aged from 80 to 89 years old (14.4 per million). The 2-year overall survival (OS) in NSAA, SAA, and VSAA were 65.5%, 49.3%, and 20.1%, respectively (P < 0.001). With regard to the response to immunosuppressive therapy, the overall response rate (ORR) in SAA/VSAA treated with rabbit anti-thymocyte globulin with/without cyclosporin A (rATG ± CsA) were significantly superior to those treated with CsA alone, or anabolic steroids (44.4% vs 36.4% and 31.2%, respectively, P < 0.001). The 2-year OS in SAA/VSAA treated with rATG ± CsA, CsA, and anabolic steroids were 54.8%, 54.5%, and 37.6% (P = 0.037), respectively. The incidence of adult AA in Thailand is higher than those in Western countries, and the peak incidence is in the elderly. rATG ± CsA provided a better response than anabolic steroids, translating to the superior survival in SAA/VSAA treated with rATG ± CsA., (© 2021. The Author(s).)

Event-free survival at 12 months (EFS12) is a surrogate endpoint for long-term outcomes in many histologic lymphoma subtypes. However, most reports have primarily investigated the implication of EFS12 in advanced-stage non-Hodgkin lymphoma (NHL). There are limited data regarding the significance of EFS12 in early-stage NHL. Herein, we evaluated the prognostic significance of EFS12 in patients with stage 1 diffuse large B-cell lymphoma (DLBCL). Out of 282 patients with stage 1 DLBCL who received intensive therapy, 227 (80.5%) achieved EFS12. The 4-year overall survival (OS) was 91.4% and 4.0% for patients who achieved and failed to achieve EFS12, respectively. Multivariable analyses demonstrated response to treatment and achievement of EFS12 as independent predictors for OS. In conclusion, our study demonstrated EFS12 as a powerful prognostic factor for stage 1 DLBCL. Further validation in more extensive prospective studies is warranted.

Introduction: Peripheral T cell NHL (PTCL) and natural killer/T cell NHL (NKTCL) are relatively rare disorders. Data on clinical presentation, treatment and outcome are limited especially in older age groups., Methods: We identified 127 patients with PTCL and NKTCL, excluding cutaneous T/NK cell lymphoma, aged over 60 years old from Thailand nationwide multicenter registry., Results: Of 127 patients, median age of diagnosis was 67 years old. Patients aged older than 75 years old had similar characteristics to younger (60-74 years old) but higher comorbidity index. Seventy-nine patients (62.2%) received intensive/definite multi-agent chemotherapy, however, the proportion was significant lower in older patients (70.4% vs 34.5%, p < .001). After a median follow up duration of 17.3 months, 2-year progression free survival and overall survival were 38.1% and 48.5%. Univariate and multivariable analysis demonstrated older age, poor performance status and absence of definite multi-agent chemotherapy were associated with inferior survival. Definite multi-agent lymphoma specific chemotherapy was an independent factor for overall survival after adjustment for age, comorbidity index, performance status and prognostic index for T cell lymphoma., Conclusion: Despite overall poor prognosis of PTCL and NKTCL in older adults, chemotherapy could result in objective response and long-term survival in selected patients of this vulnerable age group thus emphasizing the importance of comprehensive geriatric evaluation., (Copyright © 2019. Published by Elsevier Ltd.)

Event free survival at 24 months (EFS24) has been described as a powerful predictor for outcome in several subtypes of B cell lymphoma. However, it was limitedly described in T cell lymphoma. We explored the implication of EFS24 as a predictor marker for peripheral T cell lymphoma (PTCL). We reviewed 293 systemic PTCL patients at 13 nationwide major university hospitals in Thailand from 2007 to 2014. The median event free survival (EFS) and overall survival (OS) of PTCL patients in our cohort was 16.3 and 27.7 months with corresponding 2-year EFS and 2-year OS of 45.8% and 51.9%, respectively. A total of 118 patients achieved EFS24 (no events during the first 24 mo). Patients who achieved EFS24 had better OS than patients who did not (2-y OS 92% vs 18.8%; HR, 0.1; P < .001). The standardized mortality ratio of patients achieving EFS24 was 18.7 (95% CI, 14.6-22.8). Multivariable analysis demonstrated performance status, histologic subtype, remission status, and EFS24 achievement as independent predictors for OS. Our study affirmed the value of EFS24 as a powerful prognostic factor for PTCL. Further validation in prospective study setting is warranted., (©2019 John Wiley & Sons, Ltd.)

Systemic reports on the descriptive epidemiology of non-Hodgkin lymphoma (NHL) from Southeast Asia are scarce. A nationwide multi-institutional registry was conducted to compare the histopathology, clinical features, and survival of Thai adult patients with NHL using large registries, especially those from Far East Asia (FEA). Using a web-based registry system, 13 major medical centers from the 4 geographic regions of Thailand prospectively collected, from 2007 to 2014, the diagnostic pathology, according to the World Health Organization classification, 2008, clinical features and survival of 4056 patients who were newly diagnosed with NHL. The median age of the patients was 56 years (range, 16-99 years). The male-to-female ratio was 1.3:1. From the total of 4056 patients, T/NK-cell lymphoma (TNKCL) accounted for 12.6% of cases, and 5.1% had human immunodeficiency virus-associated lymphoma. The four leading histological subtypes were diffuse large B-cell lymphoma, not otherwise specified (58.1%); follicular lymphoma (5.6%); extranodal mucosa-associated lymphoid tissue lymphoma (5.2%); and peripheral T-cell lymphoma, not otherwise specified (4.0%). With a median follow-up duration of 46.1 months, the median overall survival of B-cell NHL was significantly longer than that of patients with TNKCL (76.5 vs 28.8 months, P = .0001). Compared to FEA, the Thai registry had an approximately one-half lower relative frequency of TNKCL; the prevalence of extranodal mucosa-associated lymphoid tissue lymphoma was much lower than in Korea, and the frequency of extranodal TNKCL, nasal type, was strikingly low compared to China. It is concluded that while the median age of Thai patients with NHL was approximately a decade younger than for Caucasians, the long-term survival rates for most histological subtypes were comparable. While the histological distribution generally complied with the characteristic Asian features, some differences from FEA were observed., (Copyright © 2017 John Wiley & Sons, Ltd.)

Introduction: Thalassemia-related complications are one of the main factors that increase morbidity and mortality in aging patients with thalassemia. This study was aimed to report the prevalence and clinical risk factors for the complications in thalassemia., Methods: A multi-center prospective cohort study was conducted in patients with thalassemia aged ≥10 years old. Thalassemia-related complications were heart failure, pulmonary hypertension, extramedullary hematopoiesis, endocrine disorders, infections, thrombosis and leg ulcers. The clinical parameters significantly associated with the complications were analyzed by logistic regression methods., Results: The prevalence of thalassemia-related complications was 60.5% in patients with transfusion-dependent thalassemia (TDT) and 43% in patients with non-transfusion-dependent thalassemia (NTDT). Splenectomy was statistically associated with complications in both TDT and NTDT patients (adjusted odds ratio (AOR) = 7.4, p-value = 0.0001 and AOR = 2.6, p-value = 0.001). Age ≥50 years old (AOR = 2.9, p-value = 0.04) and female gender (AOR = 0.5, p-value = 0.03) were statistically associated with the complications in patients with NTDT., Conclusion: Nearly half of the patients in this cohort had disease-related complications. Splenectomy and advanced age were important factors for complication involvement. Early screening for the complications may reduce the morbidity and mortality in patients with thalassemia.

Background: Paraspinal extramedullary hematopoiesis (EMH) is uncommon, but it is one of major complications of increased morbidity in patients with thalassemia., Objective: To develop a clinical risk score for predicting paraspinal extramedullary hematopoiesis in patients with thalassemia., Material and Method: A retrospective study was conducted in adult patients with thalassemia at Srinagarind Hospital, Khon Kaen University (KKU) and Udonthani Hospital, Thailand. Paraspinal EMH was defined as radiologic evidence of EMH foci with or without symptoms. The clinical parameters significantly associated with EMH were entered into the logistic regression model. The risk score was derived from the final model’s coefficients. A receiver-operating characteristic (ROC) curve was constructed to determine the area under the ROC curve and the cut-off point., Results: The KKU-EMH score included: 1) age greater than 25 year (2 points) and 2) thalassemic facie (3 points). Using the cut-off of 5 points, the score showed good discrimination with an area under the ROC curve of 0.83 (95% CI 0.76 to 0.90)., Conclusion: Advanced age and thalassemic facie are independent risk factors for paraspinal EMH in patients with thalassemia. The KKU-EMH score is a practical score. It can be used as a screening tool for paraspinal EMH in patients with β-thalassemia.

Secondary central nervous system (CNS) relapse is a serious and fatal complication of diffuse large B cell lymphoma (DLBCL). Data on secondary CNS (SCNS) relapse were mostly obtained from western countries with limited data from developing countries. We analyzed the data of 2034 newly diagnosed DLBCL patients enrolled into the multi-center registry under Thai Lymphoma Study Group from setting. The incidence, September 2006 to December 2013 to represent outcome from a resource limited pattern, management, and outcome of SCNS relapse were described. The 2-year cumulative incidence (CI) of SCNS relapse was 2.7 %. A total of 729, 1024, and 281 patients were classified as low-, intermediate-, and high-risk CNS international prognostic index (CNS-IPI) with corresponding 2-year CI of SCNS relapse of 1.5, 3.1, and 4.6 %, respectively (p < 0.001). Univariate analysis demonstrated advance stage disease, poor performance status, elevated lactate dehydrogenase, presence of B symptoms, more than one extranodal organ involvement, high IPI, and high CNS-IPI group as predictive factors for SCNS relapse. Rituximab exposure and intrathecal chemoprophylaxis offered no protective effect against SCNS relapse. At the time of analysis, six patients were alive. Median OS in SCNS relapsed patients was significantly shorter than relapsed patients without CNS involvement (13.2 vs 22.6 months) (p < 0.001). Primary causes of death were progressive disease (n = 35, 63.6 %) and infection (n = 9, 16.7 %). In conclusion, although the incidence of SCNS relapse in our cohort was low, the prognosis was dismal. Prophylaxis for SCNS involvement was underused even in high-risk patients. Novel approaches for SCNS relapse prophylaxis and managements are warranted.

The FLT3-ITD mutation is one of the most frequent genetic abnormalities in acute myeloid leukemia (AML) where it is associated with a poor prognosis. The FLT3-ITD mutation could, therefore, be a potential molecular prognostic marker important for risk-stratified treatment options. We amplified the FLT3 gene at exon 14 and 15 in 52 AML patients (aged between 2 months and 74 years) from 4 referral centers (a university hospital and 3 regional hospitals in Northeast Thailand), using a simple PCR method. FLT3-ITD mutations were found in 10 patients (19.2%), being more common in adults than in children (21.1% vs. 14.3%) and more prevalent in patients with acute promyelocytic leukemia (AML-M3) than AML-non M3 (4 of 10 AML-M3 vs. 6 of 42 AML- non M3 patients). Duplication sequences varied in size-between 27 and 171 nucleotides (median=63.5) and in their location. FLT3-ITD mutations with common duplication sequences accounted for a significant percentage in AML patients in northeastern Thailand. This simple PCR method is feasible for routine laboratory practice and these data could help tailor use of the national protocol for AML.

Introduction: Bacterial infection is one of the major causes of death in patients with thalassemia. Clinical predictive factors for severe bacterial infection were evaluated in patients with non-transfusion-dependent thalassemia (NTDT)., Methods: A retrospective study was conducted of patients with NTDT aged ≥ 10 years at Srinagarind Hospital, Khon Kaen University, Thailand. Clinical characteristics and potential clinical risk factors for bacterial infection were collected. Risk factors for bacterial infection were evaluated by multivariate logistic regression analysis., Results: A severe bacterial infection was found in 11 of the total 211 patients with NTDT (5.2%). None of the clinical factors assessed was shown to be statistically associated with severe bacterial infection in patients with NTDT. However, three factors were demonstrated to be potential predictive factors for severe bacterial infection: time after splenectomy >10 years, deferoxamine therapy, and serum ferritin >1000 ng/ml. None of the patients died from infection., Conclusion: The prevalence of bacterial infection in patients with NTDT was found to be moderate. Time after splenectomy >10 years, deferoxamine therapy, and iron overload may be clinical risk factors for severe bacterial infection in patients with NTDT. Bacterial infection should be recognized in splenectomized patients with NTDT, particularly those who have an iron overload., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Pulmonary hypertension (PH) is a major complication in patients with non-transfusion-dependent thalassemia (NTDT). The risk score was developed to be a screening test for PH risk in these patients., Methods: A multi-center study was conducted in patients with NTDT aged ≥10 years old. PH risk was defined as tricuspid regurgitation velocity >2.9 m/s by echocardiography. The clinical parameters significantly associated with PH were entered into the logistic regression model., Results: The E-SAAN score included (1) age >35 years (2.5 points), (2) time after splenectomy >5 years (2.5 points), and (3) β-thalassemia/hemoglobin E (2 points). Using the cut-off point of 4.5 points, the score showed a good discrimination in the validating group with an area under receiver-operating characteristics curve of 0.88 (95% CI 0.8-0.95)., Conclusion: The E-SAAN score is a simple and practical score which can be used as a screening test for PH risk in patients with NTDT.

Immune thrombocytopenic purpura (ITP) is the condition caused by increased platelet destruction and or decreased platelet production. Previous studies have demonstrated the association and efficacy of Helicobacter pylori (H. pylori) eradication therapy in patients with chronic ITP. Data in Thai patients, however, are limited. A prospective cross-sectional analytic study was conducted in adult patients with chronic ITP to determine the prevalence and clinical predictive factors of H. pylori infection and evaluate the efficacy of H. pylori eradication therapy. H. pylori-infected patients received eradication therapy (omeprazole 40 mg/day, clarithromycin 1000 mg/day, amoxicillin 2000 mg/day) for 2 weeks. The platelet counts at baseline and monthly for 6 months after the end of treatment were evaluated. Of the 25 patients, 9 patients (36%) had H.pylori infection. H. pylori infection is higher among women than men. There were two clinical factors included 1) relapsed ITP 2) response after the first-line treatment statistically proven to be associated with H. pylori infection with an odds ratio and p value of 7.7, p = 0.035 and ND (not determined due to small sample size), p < 0.001. Nearly 80% of infected patients had the platelet count response after eradication therapy with the median time to response of 4 months. The prevalence of H. pylori infection is modest in Thai adult patients with chronic ITP. A history of relapsed ITP and high quality of response after first-line treatment indicated H. pylori infection. Therefore, the urea breath test should be recommended in patients who have a relapsed ITP condition with a history of good response after first-line therapy.

Introduction: Pulmonary hypertension is one of the major complications in patients with non-transfusion-dependent thalassemia (NTDT). Patients with NTDT have distinct genetic subgroups. Therefore, the effects of different genotype groups on pulmonary hypertension risk in patients with NTDT were assessed., Methods: A cross-sectional study was conducted in patients with NTDT aged ≥ 10 yr old at Srinagarind University Hospital and Udonthani Hospital, Thailand. Pulmonary hypertension risk was defined as peak tricuspid regurgitation velocity > 2.9 m/s by trans-thoracic echocardiography. Clinical characteristics and laboratory data that literature has indicated as risk factors for pulmonary hypertension were collected. The effect of genotype group on pulmonary hypertension risk was evaluated by using multivariate logistic regression analysis., Results: Of 219 patients, pulmonary hypertension risk was found in 24 patients (10.96%). All patients were categorized into two groups according to genetic data that included: (i) β-thalassemia (139, 63.5%), (ii) α-thalassemia and combined α and β-thalassemia (80, 36.5%). Genotype groups were statistically and significantly associated with pulmonary hypertension risk based on the adjusted odds ratios after adjustment for other factors. Patients with β-thalassemia had a statistically significant higher risk for pulmonary hypertension risk (odds ratio = 9.47, P = 0.036) compared to patients with α-thalassemia and patients with combined α and β-thalassemia., Conclusion: The genotype group is an independent risk factor for pulmonary hypertension in patients with NTDT. Echocardiography should be routinely recommended for all patients with β-thalassemia. Routine screening in patients with α-thalassemia and combined α and β-thalassemia, however, may not be necessary or should focus on the older population., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The impact of health insurance with inequitable rituximab coverage on the survival of patients with diffuse large B-cell lymphoma (DLBCL) has never been reported. We conducted a nationwide multicenter analysis on the outcome of 553 adult patients consecutively diagnosed with DLBCL between July 2003 and June 2006, in whom treatment cost was reimbursed under the Civil Servant Medical Benefit Scheme (CSMBS) (n =201) or the Universal Coverage Scheme (UCS) (n =352). The international prognostic index was comparable between the two payment groups. Rituximab-based therapy was administered in 45.3% and 3.1% of CSMBS and UCS patients, respectively (p <0.001). With a median follow-up of 24.6 months, the 6-year progression-free survival (PFS) was superior for CSMBS patients (34.2 vs. 23.2%, p =0.005). "Not treated with rituximab-based therapy" was the strongest adverse prognostic feature indicating a short PFS (hazard ratio 2.1, p <0.001). It is concluded that lack of access to rituximab is the principal factor accounting for the inferior PFS observed in Thai patients with DLBCL who are treated under the UCS.

Objectives: Peripheral cytopenia is frequently found among patients with systemic lupus erythematosus (SLE). Bone marrow examination is usually considered in most cases; however, the incidence and association between cytopenia and disorders of the bone marrow remain unclear. We therefore conducted a prospective, cross-sectional, analytical study among patients with SLE and peripheral cytopenia to determine the incidence of bone marrow abnormalities and to find predictive factors for bone marrow examination., Results: Of the 41 patients, 20 had bone marrow abnormalities that could be categorised into six groups: hypocellularity (50%), plasmacytosis (35%), haemophagocytosis (30%), dyserythropoiesis (10%), aplastic marrow (10%) and myelofibrosis (5%). Most of the patients (75.6%) had moderate to severe, active disease and recovery from the cytopenia occurred after treatment of the SLE. None of the clinical factors was statistically proven to be associated with bone marrow abnormalities; however, 3 factors indicated an active disease status including (a) the SLEDAI score (b) the number of organs involved and (c) previous immunosuppressive drug therapy. All of these are potentially predictive factors of bone marrow abnormalities., Conclusions: The incidence of bone marrow abnormalities is high among patients with SLE and peripheral cytopenia. Bone marrow may be one of the common targets of organs affected by immune mechanisms in active SLE. Peripheral cytopenia can be subsequently improved after treatment of the disease; therefore, bone marrow examination should be recommended among patients whose cytopenia does not recover after conventional therapy.

Background: Immune thrombocytopenic purpura (ITP) is not rare disease and it ispotentially fatal, particularly in patients with bleeding events which usually lead to hospitalization. Current data on the impact and disease burden of ITP in Thailand are lacking., Objective: To determine admission rate, mortality rate, hospital cost, length of hospital stay, co-morbidities, treatment and major bleeding events in patients with ITP., Material and Method: The authors analyzed the data of inpatients with a diagnosis of ITP according to ICD10 coded D69.3 which were retrieved from a nationwide health financing schemes in fiscal 2010. The data were analyzed by age groups, gender and health financing schemes., Results: The overall admission rate and mortality rate were 7.68 and 0.29 per 100,000 populations, respectively and increased with age. Women were predominant. Average hospital costs and hospital stays were 27,133 Baht and 6.7 days per admission, respectively and slightly higher among men than women. The most common co-morbidity was hypertension. Gastrointestinal hemorrhage was the most common bleeding event which was 21.5 per 1,000 admissions. Patients in the civil servant medical benefit scheme had the highest percentage of high cost treatment accessibility., Conclusion: The admission rate, mortality rate and major bleeding events increased with age and was higher among women than men. Average hospital cost and length of hospital stay are higher in men than women. Common co-morbidities may be related to the treatment of ITP There are the differences in high-cost treatment accessibility between health insurance schemes.

Background: Thalassemia is a common genetic disease in Thailand. However, current data on the impact and disease burden of thalassemia in Thailand remains limited., Objective: To determine the admission rate, OPD visit rate, mortality rate, hospital cost, length of hospital stay, blood transfusion rate and major complications rate in patients with thalassemia., Material and Method: The present study analyzed the data of inpatients and outpatients with a diagnosis of thalssemia according to ICD10 coded D56, D56.0, D56.1, D56.2, D56.3, D56.4, D56.8 and D56.9 which came from nationwide health financing schemes in the fiscal year 2010., Results: The overall admission rate and OPD visit rate were 154 and 562 per 100,000 populations and higher in children and adolescents. The overall mortality rate was 1.13 per 100,000 populations. The total healthcare cost was 744,998,997 Baht or US$ 23,486,727 per year. Blood transfusion rate was significantly higher among children and adolescents. The thalassemia-related complications commonly occurred at the second and the third decades of life., Conclusion: The admission rate, OPD visit rate, blood transfusion rate were higher among children and adolescents. The total healthcare cost was high which was nearly 745 million Baht per year. The hospital cost, length of stay and major complications were increased with age.

The authors reported a case of systemic lupus erythematosus (SLE) with an unusual presentation. The patient presented with acute febrile illness along with progressive pancytopenia related to increasing hemophagocytic activity of histiocytes in the bone marrow. Concomitant polyarthritis, myositis, nephritis, high titer of antinuclear factor (1:2,560) and positive test for anti-DNA antibody made him fit the diagnostic criteria of SLE. No definite evidence of associated infections was confirmed by bacteriologic, serologic and viral studies. He did not respond to empiric antibiotic therapy but dramatically responded to corticosteroid treatment. Therefore, diagnosis of acute lupus hemophagocytic syndrome was made. The clinical presentation, laboratory diagnosis, and management of the patient are discussed and the literature was reviewed and presented.

Background: Geographic variations in the histopathologic pattern of non-Hodgkin's lymphoma (NHL) are well documented. Insight into this epidemiologic data might shed light on the underlying etiology. Currently, there is a paucity of information regarding the pattern of NHL occurring in Thailand and Southeast Asia. The current nationwide study was undertaken to obtain a clearer definition of the disease among Thais and to compare this information with data from other Asian and Western countries., Methods: A retrospective analysis of histopathologic subtypes and clinical features was conducted in 1391 patients (age > or = 15 years) with NHL, who were treated at 6 major medical centers in 4 representative areas of Thailand. One hundred and thirty unselected cases were immunohistochemically studied. The reports from other countries used for comparison were identified through a computerized search on MEDLINE., Results: Of the total cases studied, follicular lymphomas constituted 3.8% and diffuse lymphomas 91.4%. The frequency of low and intermediate grade (including large cell immunoblastic, using the Working Formulation) were 12.8% and 72.9%, respectively. The most common histologic subtype was the diffuse large cell and large cell immunoblastic entity, which constituted 39.9% of the cases studied. The rate of small lymphocytic and diffuse small cleaved subtypes were higher than in the United States. Of the 130 cases studied, T-cell lymphoma comprised 16.1%, which was much less than in Japan, China, or Taiwan., Conclusions: The histopathologic pattern of NHL in Thailand was characterized by the features noted for Asia, i.e., a low rate of the follicular entity and a preponderance of the diffuse aggressive subtypes. In addition, the frequency of the small lymphocytic and diffuse small cleaved subtypes were increased compared with the Western population and the rate of T-cell lymphoma appeared to be less than in Far East Asia.