The World Health Organization classification of malignant lymphoma: incidence and clinical prognosis in HTLV-1-endemic area of Fukuoka

Diagnostic outcomes of bone marrow aspirate and trephine biopsies performed at a hospital in KwaZulu-Natal, South Africa

Background

Bone marrow aspiration and trephine biopsy (BMAT) are widely performed in adults to evaluate haematological and malignant conditions. However, the diagnostic yield from the procedure in unselected patients in the South African public sector has not previously been described.

Objectives

We identified the main indications and most common diagnoses encountered for BMAT and described the demographic and blood profiles of patients, including HIV-positive patients, who had undergone the procedure at a tertiary hospital in KwaZulu-Natal.

Methods

We retrospectively reviewed laboratory data from January 2016 to December 2016 for all patients aged ≥ 13 years who underwent the procedure and stratified findings by demographic data.

Results

Among 120 BMAT biopsies studied, 80 (67%) cases were performed to evaluate suspected malignancy and a further 40 (33%) cases for non-malignant indications. The main indications for bone marrow examination were: cytopenias 38 (32%), lymphoma 35 (29%), leukaemia 21 (18%), and multiple myeloma 17 (14%). BMAT results revealed that 60 cases (50%) were malignant in origin, 30 cases (25%) were non-malignant and 30 cases (25%) were classified as normal. The common diagnoses were: leukaemia, 24 (20%); multiple myeloma, 16 (13%) and lymphoma, 13 (11%). Cases aged ≥ 50 years were more likely to have a malignant diagnosis (odds ratio: 5.8 (95% confidence interval: 2.2–17.1) p-value < 0.001).

Conclusion

The diagnostic yield of BMAT was high, with significant abnormalities detected in three quarters of cases. Haematological malignancy was the more common diagnosis. Increasing age was associated with an increase in reporting of haematology malignancy.

p30 protein: a critical regulator of HTLV-1 viral latency and host immunity

The extraordinarily high prevalence of HTLV-1 subtype C (HTLV-1C) in some isolated indigenous communities in Oceania and the severity of the health conditions associated with the virus impress the great need for basic and translational research to prevent and treat HTLV-1 infection. The genome of the virus’s most common subtype, HTLV-1A, encodes structural, enzymatic, and regulatory proteins that contribute to viral persistence and pathogenesis. Among these is the p30 protein encoded by the doubly spliced Tax-orf II mRNA, a nuclear/nucleolar protein with both transcriptional and post-transcriptional activity. The p30 protein inhibits the productive replication cycle via nuclear retention of the mRNA that encodes for both the viral transcriptional trans-activator Tax, and the Rex proteins that regulate the transport of incompletely spliced viral mRNA to the cytoplasm. In myeloid cells, p30 inhibits the PU-1 transcription factor that regulates interferon expression and is a critical mediator of innate and adaptive immunity. Furthermore, p30 alters gene expression, cell cycle progression, and DNA damage responses in T-cells, raising the hypothesis that p30 may directly contribute to T cell transformation. By fine-tuning viral expression while also inhibiting host innate responses, p30 is likely essential for viral infection and persistence. This concept is supported by the finding that macaques, a natural host for the closely genetically related simian T-cell leukemia virus 1 (STLV-1), exposed to an HTLV-1 knockout for p30 expression by a single point mutation do not became infected unless reversion and selection of the wild type HTLV-1 genotype occurs. All together, these data suggest that inhibition of p30 may help to curb and eventually eradicate viral infection by exposing infected cells to an effective host immune response.

Clinicopathological analysis of sinonasal malignant lymphoma in an HTLV-1 endemic area in Japan -special focus on primary sinonasal diffuse large B-cell lymphoma

The present study investigated histological subtypes of lymphoma in patients newly diagnosed with malignant lymphoma in the human T-cell leukemia virus type 1 (HTLV-1) endemic area of Japan, and further analyzed the clinicopathological features and clinical outcomes of patients with primary sinonasal lymphoma. We retrospectively examined 151 patients aged 18-90 years in Fukuoka, Japan. Subtypes of lymphoma were determined according to the WHO classification. Among the 151 patients, 104 were diagnosed with malignant lymphoma, including 96 at the time of initial diagnosis. Ninety-two of the 96 lymphomas (96%) were non-Hodgkin lymphoma. Mature B-cell neoplasms comprised 78% (n = 75). Primary lymphoma of the sinonasal cavity was found in six patients (6%). The histological subtype of sinonasal lymphoma was diffuse large B-cell lymphoma (DLBCL) in all six tumors. Furthermore, overall survival was significantly different among three distinct DLBCL patient groups, including primary sinonasal lymphoma patients (p = 0.0016; 3-year overall survival: sinonasal DLBCL group, 53%; DLBCL of the CNS group, 0%; other DLBCL group, 83%). Our study suggests that primary DLBCL of the sinonasal tract is a distinct disease entity of DLBCL.

Subtype-specific epidemiology of lymphoid malignancies in Taiwan compared to Japan and the United States, 2002-2012

BACKGROUND

There are many unrevealed parts regarding lymphoma etiology. Previous studies suggested differences in lymphoma epidemiology among countries existed; however, some were one-center studies that were not enough to represent the whole population.

OBJECTIVE

To provide epidemiological information on lymphoma within Taiwanese and to compare the data with that in Japan and the United States.

METHODS

We used Taiwan Cancer Registry Database as our data source. Patients with lymphoma were identified through the ICD-O-3 codes and those with non-Hodgkin lymphoma (NHL) were categorized into three major types and 13 subtypes according to 2008 WHO classification. Incidence of lymphoma was adjusted according to the 2000 world standard population.

RESULTS

During 2002-2012, 21 929 cases were diagnosed with four major types of lymphoma in Taiwan. Aggressive B-cell lymphoma (52.21%, N = 11 450) was the most common type of NHL. Median age at diagnosis of aggressive B-cell lymphoma was the eldest (63.0-65.0 years). Male excess in T/NK-cell lymphoma was the most obvious (sex ratio: 1.39-2.07). The incidence of NK/T-cell lymphoma, nasal type, was higher (male: 0.16-0.34 per 100 000, female: 0.06-0.16 per 100 000) in Taiwan than that in the United States and Japan.

CONCLUSION

This is the first population-based study in Taiwan to investigate subtype-specific epidemiology of lymphoma. The incidence rates of lymphoma in Taiwan are mostly lower than those in the United States and higher or comparable to those in Japan except for NK/T-cell lymphoma, nasal type, whose age-adjusted incidence in Taiwan is the highest.

Prognostic value of baseline, interim and end-of-treatment 18F-FDG PET/CT parameters in extranodal natural killer/T-cell lymphoma: A meta-analysis

METHODS

We searched the PubMed, EMBASE, Cochrane Library and Medline databases for eligible articles. SUVmax, MTV, and TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT were regarded as efficacy data. Combined hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were estimated using RevMan 5.3 software.

RESULTS

Nine trials with a total of 535 ENKTL patients were included. SUVmax, MTV and TLG on B-PET/CT were significantly associated with PFS with HRs of 2.78 (95%CI 1.54-5.03), 3.61 (95%CI 1.96-6.65) and 5.62 (95%CI 1.94-16.33), respectively, and with OS with HRs of 4.78 (95%CI 2.29-9.96), 3.20 (95%CI 1.55-6.60) and 7.76 (95%CI 1.79-33.58), respectively. For the DS on I-PET/CT, the HRs for PFS and OS were 5.15 (95%CI 2.71-9.80) and 5.80 (95%CI 2.28-14.73), respectively. Similarly, the DS on E-PET/CT was a significant predictor of PFS and OS with HRs of 3.65 (95%CI 2.13-6.26) and 3.32 (95%CI 1.79-6.15), respectively.

CONCLUSION

Our results suggest that SUVmax, MTV, TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT may be significant prognostic indicators for PFS and OS in ENKTL patients. Moreover, TLG tends to be superior to SUVmax and MTV on B-PET/CT for predicting survival of ENKTL patients. Therefore, response monitoring and prognostication assessments based on multiple PET/CT parameters should be considered in the management of ENKTL patients.

Nationwide Statistical Analysis of Lymphoid Malignancies in Korea

Purpose

Regional differences in the incidence of lymphoid malignancies have been reported worldwide, but there has been no large-scale epidemiologic analysis in Korea. The aim of this study was to provide a nationwide population-based statistical analysis of Korean patients with lymphoid malignancies.

Materials and Methods

The Korea Central Cancer Registry analyzed the incidence and survival of patients with lymphoid malignancies from the Korean National Cancer Incidence Database. Diseases were grouped by clinically relevant categories based on the 2008 World Health Organization classification.

Results

Overall 65,948 lymphoid diseases were identified between 1999 and 2012. The incidence of most subtypes increased with age, except for precursor cell neoplasms. Male predominance (male:female ratio=1.28:1) was observed. In 2012, annual age-standardized incidence rates per 100,000 persons of Hodgkin’s lymphoma, mature B-cell neoplasm, mature T/natural killer (NK)–cell neoplasm, and precursor cell neoplasm were 0.46, 6.60, 0.95, and 1.50, respectively, and they increased yearly from 1999. Composite Hodgkin’s and non-Hodgkin’s lymphomas were extremely rare. Survival improvement estimated using 5-year relative survival rate was observed in patients with Hodgkin’s lymphoma (71.1%-83.0%), diffuse large B-cell lymphoma (49.5%-61.5%), plasma cell neoplasms (20.2%-36.9%), and lymphoblastic lymphoma/leukemia (41.5%-56.3%) between 1993 and 2012. However, survival rates of T/NK-cell lymphoma (excluding cutaneous T-cell lymphoma) ranged from 40.5%-43.5% during the study period. Survival rates decreased with age in most subtypes.

Conclusion

This report presented the subtype-specific statistical analysis of lymphoid malignancies in the Korean population, showing increasing incidences and survival rates in most subtypes.

Non-biased and complete case registration of lymphoid leukemia and lymphoma for five years: a first representative index of Japan from an epidemiologically stable Miyagi Prefecture

Previous worldwide epidemiological studies on lymphoid leukemia and/or lymphoma (LL/L) had considerable bias because of difficulty in covering all clinical departments of hospitals in a restricted area (population base). These studies may not have reflected the actual number of newly diagnosed cases (incidence) strictly, or the true LL/L subtype frequencies. We searched all cases of newly diagnosed LL/L in Miyagi Prefecture over a 5-year period, including those that were discovered as LL/L sorely after autopsy. We registered the actual number of 2098 cases in the prefecture and calculated an accurate incidence rate (17.8 per 100,000 persons). Additionally, we identified more realistic and detailed frequencies of LL/L subtypes including the leukemic phase of some lymphomas. As Miyagi Prefecture is an area in which the population dynamics are relatively stable and representative of Japan, the result of our epidemiological study can be used as the first representative index of LL/L for Japan.

Optimizing Management of Patients with Adult T Cell Leukemia-Lymphoma

Adult T cell leukemia-lymphoma is a rare disease with a high mortality rate, and is challenging for the clinician. Early allogeneic stem cell transplant can confer durable remission. As novel therapeutic agents become available to treat T cell malignancies, it is increasingly important that medical oncologists, hematologists, and hematopathologists recognize and accurately diagnose adult T cell leukemia-lymphoma. There is no uniform standard of treatment of adult T cell leukemia-lymphoma, and clinical trials remain critical to improving outcomes. Here we present one management approach based on the recent advances in treatment for adult T cell leukemia-lymphoma patients.

Cutaneous lymphoma in Japan: a nationwide study of 1733 patients

Types of cutaneous lymphoma (CL) and their incidences may vary among geographic areas or ethnic groups. The present study aimed to investigate the incidences of various CL in Japan, using epidemiological data from a nationwide registration system for CL. Between 2007 and 2011, 1733 new patients with CL were registered from over 600 dermatological institutes in Japan. The 1733 patients registered included 1485 (85.7%) patients with mature T- and natural killer (NK)-cell neoplasms, 224 (12.9%) with B-cell neoplasms and 24 (1.4%) with blastic plasmacytoid dendritic cell neoplasm. Mycosis fungoides (MF) is the most common CL subtype in the present study (750 patients, 43.3%). The proportion of MF patients with early-stage disease was 73%, similar to that of previous studies from other cohorts. The incidence rates of adult T-cell leukemia/lymphoma and extranodal NK/T-cell lymphoma, nasal type were 16.7% and 2.0%, respectively, which may account for the higher incidence of mature T- and NK-cell neoplasms in Japan, as compared with that in the USA and Europe. A male predominance was observed in most types of CL, except for several CL subtypes such as subcutaneous panniculitis-like T-cell lymphoma.

Role of infectious agents in cutaneous T-cell lymphoma: facts and controversies

The etiology of cutaneous T-cell lymphoma (CTCL) remains unknown, with potential infectious causes having been explored. This contribution evaluates the evidence suggesting an infectious etiology and pathogenesis of the disease, characterizes the relationships between various specific pathogens and CTCL, and discusses some of the difficulties in establishing a causal link between infectious agents and CTCL carcinogenesis. Researchers have evaluated CTCL specimens for evidence of infection with a variety of agents, including human T-lymphotropic virus, Epstein-Barr virus, human herpesvirus-8, and Staphylococcus aureus, although other pathogens also have been detected in CTCL. Although there is significant evidence implicating one or more infectious agents in CTCL, studies to date have not linked definitively any pathogen to disease development, and various studies have yielded conflicting results.

Classification of non-Hodgkin lymphoma in Central and South America: a review of 1028 cases

The distribution of non-Hodgkin lymphoma (NHL) subtypes differs around the world but a systematic study of Latin America has not been done. Therefore, we evaluated the relative frequencies of NHL subtypes in Central and South America (CSA). Five expert hematopathologists classified consecutive cases of NHL from 5 CSA countries using the WHO classification and compared them to 400 cases from North America (NA). Among the 1028 CSA cases, the proportions of B- and T-cell NHL and the sex distribution were similar to NA. However, the median age of B-cell NHL in CSA (59 years) was significantly lower than in NA (66 years; P < .0001). The distribution of high-grade (52.9%) and low-grade (47.1%) mature B-cell NHL in CSA was also significantly different from NA (37.5% and 62.5%; P < .0001). Diffuse large B-cell lymphoma was more common in CSA (40%) than in NA (29.2%; P < .0001), whereas the frequency of follicular lymphoma was similar in Argentina (34.1%) and NA (33.8%), and higher than the rest of CSA (17%; P < .001). Extranodal NK/T-cell NHL was also more common in CSA (P < .0001). Our study provides new objective evidence that the distribution of NHL subtypes varies significantly by geographic region and should prompt epidemiologic studies to explain these differences.

Adult T-cell leukemia: a review of epidemiological evidence

Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type I (HTLV-1) infection and often occurs in HTLV-1-endemic areas, such as southwestern Japan, the Caribbean islands, Central and South America, Intertropical Africa, and Middle East. To date, many epidemiological studies have been conducted to investigate the incidence of ATL among general population or HTLV-1 carriers and to identify a variety of laboratory, molecular, and host-specific markers to be possible predictive factors for developing ATL because HTLV-1 infection alone is not sufficient to develop ATL. This literature review focuses on the epidemiology of ATL and the risk factors for the development of ATL from HTLV-1 carriers, while keeping information on the epidemiology of HTLV-1 to a minimum. The main lines of epidemiological evidence are: (1) ATL occurs mostly in adults, at least 20-30 years after the HTLV-1 infection, (2) age at onset differs across geographic areas: the average age in the Central and South America (around 40 years old) is younger than that in Japan (around 60 years old), (3) ATL occurs in those infected in childhood, but seldom occurs in those infected in adulthood, (4) male carriers have about a three- to fivefold higher risk of developing ATL than female, (5) the estimated lifetime risk of developing ATL in HTLV-1 carriers is 6-7% for men and 2-3% for women in Japan, (6) a low anti-Tax reactivity, a high soluble interleukin-2 receptor level, a high anti-HTLV-1 titer, and high levels of circulating abnormal lymphocytes and white blood cell count are accepted risk factors for the development of ATL, and (7) a higher proviral load (more than 4 copies/100 peripheral blood mononuclear cells) is an independent risk factor for progression of ATL. Nevertheless, the current epidemiological evidence is insufficient to fully understand the oncogenesis of ATL. Further well-designed epidemiological studies are needed.

Distribution of lymphoid neoplasms in the Republic of Korea: analysis of 5318 cases according to the World Health Organization classification

Compared with the West, the overall incidence of lymphoid neoplasms is lower, and the subtype distribution is distinct in Asia. To comprehensively investigate the subtype distribution with the age and sex factors, and temporal changes of subtype proportions, we re-assessed all patients with lymphoid neoplasms diagnosed at a large oncology service in the Republic of Korea from 1989 to 2008 using the World Health Organization classifications. Of the total 5,318 patients, 66.9% had mature B-cell neoplasms, 12.5% had mature T/natural killer (NK)-cell neoplasms, 16.4% had precursor lymphoblastic leukemia/lymphoma (ALL/LBL), and 4.1% had Hodgkin's lymphoma. The most common subtypes were diffuse large B-cell lymphoma (30.5%), plasma cell myeloma (14.0%), extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma; 12.4%), B-cell ALL/LBL (11.3%), Hodgkin's lymphoma (4.1%), peripheral T-cell lymphoma unspecified (4.0%), T-cell ALL/LBL (3.9%), and extranodal NK/T-cell lymphoma of nasal type (3.9%). Most subtypes showed male predominance, with an average M/F ratio of 1.3. Most mature lymphoid neoplasms were diseases of adults (mean age, 53.5 yr), whereas ALL/LBLs were of young individuals (mean age, 20.3 yr). When the relative proportion of subtypes were compared between two decades (1989-1998 vs. 1999-2008), especially MALT lymphoma has increased in proportion, whereas T/NK-cell neoplasms and ALL/LBL have slightly decreased. In summary, the lymphoid neoplasms of Koreans shared some epidemiologic features similar to those of other countries, whereas some subtypes showed distinct features. Although the increase in incidence of lymphoid neoplasms is relatively modest in Korea, recent increase of MALT lymphoma and decrease of T/NK-cell neoplasms and ALL/LBL are interesting findings.

Primary nasal-type natural killer/T-cell lymphoma of pterygopalatine fossa

Primary tumors that originated from the pterygopalatine fossa are seen rarely. In this paper, the case of a 69-year-old woman who complained of a 2-month history of headache, extending to the left part of the face, teeth, and shoulder, is reported. She had undergone right total mastectomy and axillar dissection of a spindle cell-type metaplastic carcinoma of the breast 1 year ago. Computed tomographic and magnetic resonance images showed a mass originating from the pterygopalatine fossa. Pathologic examination of the biopsy specimen of the mass revealed a nasal-type extranodal natural killer/T-cell lymphoma with CD45 and intense CD56 staining. Our case shows that a nasal-type extranodal natural killer/T-cell lymphoma should be thought in mind for the differential diagnosis of primary tumors of the pterygopalatine fossa.

Tanzanian malignant lymphomas: WHO classification, presentation, ploidy, proliferation and HIV/EBV association

BACKGROUND

In Tanzania, the International Working Formulation [WF] rather than the WHO Classification is still being used in diagnosing malignant lymphomas (ML) and the biological characterization including the HIV/EBV association is sketchy, thus restraining comparison, prognostication and application of established therapeutic protocols.

METHODS

Archival, diagnostic ML biopsies (N = 336), available sera (N = 35) screened by ELISA for HIV antibodies and corresponding clinical/histological reports at Muhimbili National Hospital (MNH) in Tanzania between 1996 and 2006 were retrieved and evaluated. A fraction (N = 174) were analyzed by histopathology and immunohistochemistry (IHC). Selected biopsies were characterized by flow-cytometry (FC) for DNA ploidy (N = 60) and some by in-situ hybridization (ISH) for EBV-encoded RNA (EBER, N = 37).

RESULTS

A third (38.8%, 109/281) of the ML patients with available clinical information had extranodal disease presentation. A total of 158 out of 174 biopsies selected for immunophenotyping were confirmed to be ML which were mostly (84. 8%, 134/158) non-Hodgkin lymphoma (NHL). Most (83.6%, 112/134) of NHL were B-cell lymphomas (BCL) (CD20+), of which 50.9%, (57/112) were diffuse large B-cell (DLBCL). Out of the 158 confirmed MLs, 22 (13.9%) were T-cell [CD3+] lymphomas (TCL) and 24 (15.2%) were Hodgkin lymphomas (HL) [CD30+]. Furthermore, out of the 60 FC analyzed ML cases, 27 (M:F ratio 2:1) were DLBCL, a slight majority (55.6%, 15/27) with activated B-cell like (ABC) and 45% (12/27) with germinal center B-cell like (GCB) immunophenotype. Overall, 40% (24/60) ML were aneuploid mostly (63.0%, 17/27) the DLBCL and TCL (54.5%, 6/11). DNA index (DI) of FC-analyzed ML ranged from 1.103-2.407 (median = 1.51) and most (75.0%) aneuploid cases showed high (>40%) cell proliferation by Ki-67 reactivity. The majority (51.4%, 19/37) of EBER ISH analyzed lymphoma biopsies were positive. Of the serologically tested MLs, 40.0% (14/35) were HIV positive, mostly with high (> or =40.0%) Ki-67 reactivity.

CONCLUSIONS

According to the 2001 WHO Classification, most subtypes are represented in Tanzanian ML. Extranodal presentation was common among MNH lymphoma patients who also showed high aneuploidy, tumor proliferation (KI-67) and EBER positivity. DLBCL was frequent and phenotype heterogeneity appeared similar to observations in Western countries suggesting applicability of established intervention approaches. HIV was apparently associated with high ML cell proliferation but extended studies are needed to clarify this.

Array comparative genomic hybridization analysis of PTCL-U reveals a distinct subgroup with genetic alterations similar to lymphoma-type adult T-cell leukemia/lymphoma

PURPOSE

Peripheral T-cell lymphoma, unspecified (PTCL-U) comprises histopathologically and clinically heterogeneous groups. The purpose of this study was to identify subgroups with distinct genetic, histopathologic, and prognostic features.

EXPERIMENTAL DESIGN

We used array comparative genomic hybridization (CGH) for high-resolution analysis of 51 PTCL-U patients and the array data for examining possible correlations of histopathologic and clinical features. Moreover, we compared the genetic, histopathologic, and prognostic features of the PTCL-U cases with those of 59 cases of lymphoma-type adult T-cell leukemia/lymphoma (ATLL).

RESULTS

We identified 32 regions with frequent genomic imbalance, 1 region with high copy number gain at 14q32.2, and 1 region with homozygous loss at 9p21.3. Gains of 7p and 7q and loss of 9p21.3 showed a significant association with poor prognosis. PTCL-U cases with genomic imbalance showed distinct histopathologic and prognostic features compared with such cases without alteration and a marked genetic, histopathologic, and prognostic resemblance to lymphoma-type ATLL.

CONCLUSIONS

The array CGH enabled us to identify the frequently altered genomic regions with strong prognostic power among PTCL-U cases. A correlative analysis using the array CGH data disclosed a subgroup in PTCL-U with genomic alterations and with histopathologic and clinical relevance. In addition to histopathologic similarity, the strong genetic and prognostic resemblance between PTCL-U cases with genomic imbalance detected by array CGH and lymphoma-type ATLL seems to support the notion that the former may constitute a distinct PTCL-U subgroup.

Systemic varicella zoster virus reinfection in a case of angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is a rare subtype of peripheral T-cell lymphoma that causes immunological disorders such as immunosuppression, autoimmune disease-like symptoms and allergy. We report a case of a 67-year-old man with AITL who had a serious varicella zoster virus (VZV) reinfection that appeared clinically to be varicella. Forty percent of cases of AITL are associated with skin rash. A variety of cutaneous manifestations have been reported; however, the majority are macropapular eruptions that are often diagnosed as drug associated. Our study emphasizes the need to correctly diagnose opportunistic infections, such as the varicella that is documented in our patient, at early stages in AITL.

Presentation of two cases of nasal type NK/T-cell lymphoma

Nasal type NK/T-cell lymphoma is a rare type of predominantly extranodal non-Hodgkin lymphoma. Early and correct diagnosis with prompt treatment of NK/T-cell lymphoma is important in view of its potentially aggressive behavior and poor response to treatment with additional sites of tumor developing sometimes weeks or months after initial diagnosis. Unfortunately diagnosis of NK/T-cell lymphomas often proves difficult. The diagnosis is essentially based on the clinical presentation of extranodal ulcerative lesions in the upper aero-digestive tract and histopathologic analysis of biopsies using immunohistochemistry. Here we present two cases with nasal-type NK/T-cell lymphoma that illustrate that definitive diagnosis is often delayed due to the atypical initial presentation. We will discuss the pitfalls in diagnosing this rare type of neoplasm and review the treatment options.

Extranodal NK/T-cell lymphoma, nasal type

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL), previously known as lethal midline granuloma is a distinct clinico-pathological entity associated with Epstein-Barr virus that typically causes destruction of the midface, palatal and orbital walls. In addition, ENKTCL can involve the skin, soft tissue, testes, gastrointestinal and upper respiratory tract. ENKTCL neoplastic cells express some T-cell associated antigens, most commonly CD2 and cytoplasmic CD3epsilon and, in favour of an NK-cell origin, CD56. Early stage disease may respond to radiotherapy alone, however late stage disease does not respond well to any available therapies. Overall, patients with ENKTCL have a cumulative probability of survival at 5 years ranging from 37.9% to 45.3%.

Report of an International Network of Cancer Treatment and Research workshop on non-Hodgkin's lymphoma in developing countries

The International Network of Cancer Treatment and Research (INCTR) recently organized a workshop on non-Hodgkin lymphomas (NHLs) in selected developing countries with the purpose of examining existing information relating to the pathology and management of these neoplasms, and identifying potential areas for research. This report provides a summary of the information presented and is focused primarily on the pathology of NHLs in children and adults. In most countries, the WHO classification of lymphomas was used and most participating centers included immunohistochemistry using a wide array of lymphoid antibodies as part of routine diagnosis. Some of the series had been reviewed by an external panel of experts. B-cell lymphomas accounted for 82-88% of all NHLs. The proportions of chronic lymphatic leukemia (4-6%), mantle cell lymphoma (MCL, 3-5%), and plasmacytoma (2-4%) were similar in the series presented. However, there was a significant variation in the proportion of follicular lymphoma (FL), which accounted for 15% and 11% in India and Kuwait, but less than 5% in Pakistan and Egypt. All of these frequencies are significantly lower than those reported in Western series. Diffuse large B-cell lymphoma accounted for about 35% of cases in India but for more 50% in other countries, but this difference was not accounted for by an increased incidence in a single lymphoma subtype in India, but rather an apparent paucity of several subtypes (such as mantle cell and marginal zone lymphomas (MZL)) in other series. There were relatively high frequencies of Burkitt lymphoma in Egypt (7%) and precursor T-cell lymphoblastic lymphoma in India (6-7%). Peripheral T-cell lymphomas (PTCLs) (not otherwise specified and angioimmunoblastic subtypes) accounted for 3-5% of NHLs, and extranodal lymphoma of T/NK cell type was rare (<1%). These differences in the relative proportions of NHL subtypes among developing countries and between developing countries and the rest of the world presumably arise from differences in environmental and genetic factors that influence lymphomagenesis and strongly suggest that more research in developing countries would provide valuable insights into the pathogenesis of lymphoid neoplasms.

Current views in HTLV-I-associated adult T-cell leukemia/lymphoma

Epidemiological studies have demonstrated that the relative percentage of malignant lymphoid proliferations varies widely according to geographical location and ethnic populations. HTLV-I is the etiological agent of adult T-cell leukemia/lymphoma (ATLL) and is also associated with cutaneous T-cell lymphoma (CTCL). However, a definite role of HTLV-I in mycosis fungoides (MF) and/or Sezary syndrome (SS) remains controversial. While most HTLV-I-infected individuals remain asymptomatic carriers, 1-5% will develop ATLL, an invariably fatal expansion of virus-infected CD4+ T cells. This low incidence and the long latency period preceding occurrence of the disease suggest that additional factors are involved in development of ATLL. In this review, diagnosis, clinical features, and molecular pathogenesis of HTLV-I are discussed.

Clinicopathological features of extranodal lymphomas: Kuwait experience

A total of 935 patients with extranodal non-Hodgkin lymphoma (NHL) diagnosed in the period between January 1985 and December 2000 in Kuwait Cancer Center, serving the whole population of Kuwait, were used to describe the clinicopathological and epidemiological features of extranodal lymphomas in Kuwait. Extranodal lymphomas accounted for 45% of all NHL observed during this time. All NHL cases from Kuwait Cancer registry were analyzed and pathologically reclassified using the latest WHO (2000) classification. The most common lymphoma observed was diffuse large B-cell lymphoma (58.60%) followed by Burkitt s lymphoma (BL) (3.80%). In the pediatric group, BL comprises more than two thirds of all patients (77.20%). The most common extranodal sites were stomach (19.70%) and skin (17.80%) in the adult group, large intestine (29.80%) and small intestine (19.30%) in the pediatric age group. The majority (73.40%) of adult extranodal lymphomas was in stage IE-IIE and had a very good prognosis. On the contrary, the majority of pediatric extranodal lymphomas were found to be in stage III and IV. Variations in treatment policies (single agent or combined chemotherapy, radiotherapy, combined modality treatment) adopted and changed during the time period of 16 years of this retrospective study were documented.

The Relationship Between Primary Gastric B-cell Lymphoma and Immunoglobulin Heavy Chain (IgH) Gene Rearrangement – A Histopathological Study of Primary Gastric Lymphomas

The aim of this study was to review our primary gastric lymphoma cases according to the new WHO classifications and to investigate the histopathological features of B-cell lymphomas. In addition, B-cell monoclonality was analyzed for immunoglobulin heavy chain (IgH) gene rearrangement using the polymerase chain reaction at the site of the lymphoma lesion, transitional lesion, and the non-lymphoma lesion. Specimens resected from 31 primary gastric lymphomas were examined. There were 28 cases (90.3%) of B-cell lymphoma and three cases (9.7%) of T-cell lymphoma. The B-cell lymphomas were classified as low-grade mucosa-associated lymphoid tissue (MALT) lymphoma (LGML) (9%), high-grade MALT lymphoma (HGML) (42%), and diffuse large B-cell lymphoma (DLBCL) (29%). Histopathologically, lymphoepithelial lesions (LEL) were higher in LGML (100%) than in DLBCL (22%), with statistical significance (p < 0.05). A monoclonal pattern of IgH rearrangement was detected in LGML (50.0%), HGML (60.0%), and DLBCL (80.6%), with a statistically significant difference between LGML and DLBCL (p < 0.01). The IgH monoclonal pattern may reflect the gross appearance of lymphoma or the lymphoma infiltration depth. Superficial spreading and shallow growth in LGML may correspond to an oligoclonal pattern, and mass-forming and deep invasive growth in DLBCL may correspond to a more monoclonal pattern.