Bone marrow involvement by nasal NK cell lymphoma at diagnosis is uncommon

The contemporary management of cancers of the sinonasal tract in adults

Sinonasal malignancies make up <5% of all head and neck neoplasms, with an incidence of 0.5-1.0 per 100,000. The outcome of these rare malignancies has been poor, whereas significant progress has been made in the management of other cancers. The objective of the current review was to describe the incidence, causes, presentation, diagnosis, treatment, and recent developments of malignancies of the sinonasal tract. The diagnoses covered in this review included sinonasal undifferentiated carcinoma, sinonasal adenocarcinoma, sinonasal squamous cell carcinoma, and esthesioneuroblastoma, which are exclusive to the sinonasal tract. In addition, the authors covered malignances that are likely to be encountered in the sinonasal tract-primary mucosal melanoma, NUT (nuclear protein of the testis) carcinoma, and extranodal natural killer cell/T-cell lymphoma. For the purpose of keeping this review as concise and focused as possible, sarcomas and malignancies that can be classified as salivary gland neoplasms were excluded.

Evaluation of different staging systems and prognostic analysis of nasal-type extranodal NK/T-cell lymphoma based on consistent LVDP chemotherapy regimen

•

The LVDP chemotherapy regimen was effective and safe for nasal-type ENKTL.

•

The CMT yielded better survival outcomes than CT alone in nasal-type ENKTL.

•

The CASS had a better survival discrimination than the AASS.

Nasal-type extranodal NK-T-cell lymphoma (ENKTL) is a rare non-Hodgkin lymphoma. The optimal staging system for it remains undefined. In this study, we evaluated different staging systems in 205 patients with nasal-type ENKTL based on a consistent LVDP (L-asparaginase, etoposide, dexamethasone, cisplatin) regimen. All patients were staged by Ann Arbor staging system (AASS) and CA staging system (CASS). Their characteristics, treatment responses, survival outcomes, prognostic factors, and prognostic values of AASS and CASS were analyzed. The median follow-up time was 78 months. All patients received a median 4 cycles of the LVDP chemotherapy. Based on CASS, patients with stages I through IV were more evenly distributed than with AASS, and numbered at 56 (27.3%), 70 (33.2%), 45 (21.9%), and 34 (17.6%), respectively. At the end of therapy, the objective response rate (ORR) was 81.2% for all patients. For all patients, the 5-year progression-free survival (PFS) and overall survival (OS) were 61.6% and 67.8%. According to AASS, the 5-year OS of patients with stages Ⅰ through Ⅳ were 77.9%, 61.2%, 60.0%, and 38.7%, respectively (χ²=20.578, p<0.001). Based on CASS, the 5-year OS of patients with stages Ⅰ to Ⅳ were 89.1%, 65.5%, 58.6%, and 45.4%, respectively (χ²=22.973, p<0.001). In ROC analysis of OS, the area under the curve (AUC) for CASS was 0.70 and 0.64 for AASS. CASS was better in discriminating survival than AASS (p = 0.018). In conclusion, the LVDP regimen is effective for nasal-type ENKTL and the CASS has a better prognostic value in survival analysis than the AASS.

Extranodal NK/T cell lymphoma, nasal type: An updated overview

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is an aggressive malignancy associated with Epstein-Barr virus infection, with a geographic and racial predilection for some Asian and Latin American countries. ENKTCL-NT manifests as a necrotic process affecting nasal or upper aerodigestive structures and, rarely, extranasal sites such as skin, and the gastrointestinal tract. ENKTCL-NT was characterized by its poor prognosis irrespective of clinical stage and therapy. However, during the last two decades, advances in its clinicopathologic, genetic and molecular characterization have been achieved, as have changes in the chemotherapy regimens that, in combination with radiotherapy, are significantly improving the survival of these patients, especially in initial stages. For these reasons, we present an overview of the historical background of ENKTCL-NT along with an updated review of its potential etiological factors, clinicopathologic and molecular features, as well as its prognostic models, current treatment protocols, and future directions on potential promising therapeutic approaches.

Primary cardiac natural killer/T-cell lymphoma, a very rare form of lymphoma

Extranodal natural killer/T-cell lymphoma is a rare non-Hodgkin lymphoma that is divided into nasal, non-nasal, and aggressive/leukemia subtypes, according to anatomic origin and clinical manifestations, with each subtype carrying a different prognosis. We present a case of primary cardiac natural killer/T-cell lymphoma with extension to other organs in a 38-year-old man, to highlight the role of imaging in categorizing nasal versus non-nasal types. This distinction has relevant implications for patient care because the non-nasal type has a much lower survival rate.

EBV-Positive Lymphoproliferations of B- T- and NK-Cell Derivation in Non-Immunocompromised Hosts

The contribution of Epstein-Barr virus (EBV) to the development of specific types of benign lymphoproliferations and malignant lymphomas has been extensively studied since the discovery of the virus over the last 50 years. The importance and better understanding of the EBV-associated lymphoproliferative disorders (LPD) of B, T or natural killer (NK) cell type has resulted in the recognition of new entities like EBV+ mucocutaneous ulcer or the addition of chronic active EBV (CAEBV) infection in the revised 2016 World Health Organization (WHO) lymphoma classification. In this article, we review the definitions, morphology, pathogenesis, and evolving concepts of the various EBV-associated disorders including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), EBV+ mucocutaneous ulcer, DLBCL associated with chronic inflammation, fibrin-associated DLBCL, lymphomatoid granulomatosis, the EBV+ T and NK-cell LPD of childhood, aggressive NK leukaemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity of primary EBV+ nodal T- or NK-cell lymphoma. The current knowledge regarding the pathogenesis of B-cell lymphomas that can be EBV-associated including Burkitt lymphoma, plasmablastic lymphoma and classic Hodgkin lymphoma will be also explored.

Extranodal NK/T cell lymphoma and aggressive NK cell leukaemia: evidence for their origin on CD56+bright CD16-/+dim NK cells

Mature natural killer (NK) cell neoplasms are classified by the World Health Organization into extranodal NK/T cell lymphoma, nasal type (ENKTL) and aggressive NK cell leukaemia (ANKL). In order to propose their normal NK cell counterparts, we reviewed the literature on the phenotype of the neoplastic NK cells from five series of patients with ENKTL (n = 411) and seven series of patients with ANKL (n = 114) and compared with that of the normal and activated mature CD56 NK cell subsets. The tumour NK cells usually express brightly the CD56 adhesion molecule and CD94 lectin type killer receptor, and have an activation-related (cytoplasmic CD3ε, CD7, CD45RO, HLA-DR) phenotype; in contrast, CD16 and killer immunoglobulin-like receptors are frequently negative, and CD57 expression is almost never observed. These phenotypic features would suggest that ENKTL and ANKL cells do represent the neoplastic counterpart of the mature CD56 NK cells, which undergo activation and malignant transformation after Epstein-Barr virus infection.

Extranodal natural killer/T-cell lymphoma, nasal type, of the orbit mimicking recurrent orbital cellulitis

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is a rare type of lymphoma that is endemic to East Asia and parts of Central and South America. Most patients present with nasal obstruction, sinusitis, ulcer, and epistaxis due to a destructive mass involving the midline facial tissues. The patient visited our clinic approximately 1 year ago; she had right-sided orbital swelling and pain. The patient was sent to the department of ear, nose, and throat (ENT), and computed tomographic scan was performed. Computed tomographic imaging showed a soft tissue density in the right frontal, maxillary, and ethmoidal sinus and demonstrated fungal sinusitis in the right maxillary sinus. Then, she underwent the operation at ENT; her symptoms seemed to have disappeared. After 6 months, however, she had visited our clinic again because of a left-sided orbital cellulitis that seemed to be similar to the previous right-sided symptoms 1 year ago. She received treatments immediately and the operation again at ENT. In addition, a biopsy of left ethmoid sinus tissue was performed. The biopsy result revealed "chronic inflammation." However, unfortunately, the patient had a relapse of almost the same symptoms in a month. An excisional biopsy was performed for histopathologic diagnosis again. The left ethmoid sinus biopsy results were consistent with extranodal NK/T-cell lymphoma, nasal type. The patient then transferred her care to the department of internal medicine for chemotherapy. The authors demonstrate how the progressive-staging extranodal NK/T-cell lymphoma can present in a similar fashion as a recurrent orbital cellulitis.

Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders

Primary infection with Epstein-Barr virus (EBV) is usually asymptomatic and, in a normal host, EBV remains latent in B cells after primary infection for the remainder of life. Uncommonly, EBV can infect T or natural killer (NK) cells in a person with a defect in innate immunity, and EBV infection can cause unique systemic lymphoproliferative diseases (LPD) of childhood. Primary infection in young children can be complicated by hemophagocytic lymphohistiocytosis or fulminant systemic T-cell LPD of childhood. Uncommonly, patients can develop chronic active EBV (CAEBV) disease-type T/NK LPD, which includes CAEBV infection of the systemic form, hydroa vacciniforme-like T-cell LPD, and mosquito-bite hypersensitivity. The clinical course of CAEBV disease-type T/NK LPD can be smoldering, persistent or progressive, depending on the balance between viral factors and host immunity. Aggressive NK-cell leukemia, hydroa vacciniforme-like T-cell lymphoma, or uncommonly extranodal NK/T-cell lymphoma can develop in children and young adults with CAEBV disease-type T/NK-cell LPD. Extranodal T/NK-cell lymphoma is a disease of adults, and its incidence begins to increase in the third decade and comprises the major subtype of T/NK LPD throughout life. Aggressive NK-cell leukemia and nodal T/NK-cell lymphoma of the elderly are fulminant diseases, and immune senescence may be an important pathogenetic factor. This review describes the current progress in identifying different types of EBV-associated T/NK-cell LPD and includes a brief presentation of data from Korea.

Aggressive mature natural killer cell neoplasms: report on a series of 12 European patients with emphasis on flow cytometry based immunophenotype and DNA content of neoplastic natural killer cells

We report 12 cases of aggressive natural killer (NK) cell neoplasms diagnosed in Portugal, with emphasis on flow cytometry. Ten patients had extranodal NK/T cell lymphoma, nasal type and two had aggressive NK cell leukemia, and seven were men and five were women, with a median age of 50 years. NK cells brightly expressed the CD56 adhesion molecule and CD94 lectin type killer receptor and had an activation-related HLA-DR+ CD45RA+ CD45RO+ immunophenotype, in most cases. In contrast, dim CD16 expression was found in a minor proportion of cases, whereas CD57 and the CD158a and CD158e1 killer immunoglobulin-like receptors were negative. One-third of cases showed a hyperploid DNA content and nearly all had a very high S-phase proliferative rate. The phenotypic features of the neoplastic NK cells would suggest that they represent the transformed counterpart of the CD56 + bright NK cells that circulate in normal blood.

Extranodal natural killer/T cell lymphomas with extranasal disease in non-endemic regions are disseminated or have nasal primary: a study of 84 cases from India

Abstract We report a study of 84 extranodal natural killer/T cell lymphomas (ENKTCLs) from India to understand the disease pattern. Sixty-one patients had nasal disease and three had Waldeyer's ring tumors, while 20 had extranasal sites of presentation, namely: cervix (n = 1), oral cavity (n = 3), orbit (n = 3), liver (n = 1), ileum (n = 1), and soft tissue and lymph nodes (n = 9). Staging of patients with extranasal disease revealed that either they had disseminated disease or the nasal mass was missed during the initial staging. Extranasal presentation, performance status (PS), international prognostic index (IPI), Korean prognostic index, marrow involvement, radiotherapy and type of chemotherapy affected overall survival, while lymphopenia, performance status, radiotherapy and type of chemotherapy impacted disease-free survival. In the multivariate analysis, IPI and response to chemotherapy emerged as significant prognostic factors. Thus most patients with extranasal ENKTCL have a nasal lesion or disseminated disease and pure extranasal disease is uncommon in non-endemic regions.

Aggressive mature natural killer cell neoplasms: from epidemiology to diagnosis

Mature natural killer (NK) cell neoplasms are classified by the World Health Organization into NK/T cell lymphoma, nasal type (NKTCL), aggressive NK-cell leukemia (ANKCL) and chronic lymphoproliferative disorders of NK-cells, the latter being considered provisionally. NKTCL and ANKCL are rare diseases, with higher prevalence in Asia, Central and South America. Most NKTCL present extranodal, as a destructive tumor affecting the nose and upper aerodigestive tract (nasal NKTCL) or any organ or tissue (extranasal NKTCL) whereas ANKCL manifests as a systemic disease with multiorgan involvement and naturally evolutes to death in a few weeks. The histopathological hallmark of these aggressive NK-cell tumors is a polymorphic neoplastic infiltrate with angiocentricity, angiodestruction and tissue necrosis. The tumor cells have cytoplasmatic azurophilic granules and usually show a CD45(+bright), CD2(+), sCD3(-), cytCD3epsilon(+), CD56(+bright), CD16(−/+), cytotoxic granules molecules(+) phenotype. T-cell receptor genes are in germ-line configuration. Epstein-Barr virus (EBV) -encoded membrane proteins and early region EBV RNA are usually detected on lymphoma cells, with a pattern suggestive of a latent viral infection type II. Complex chromosomal abnormalities are frequent and loss of chromosomes 6q, 11q, 13q, and 17p are recurrent aberrations. The rarity of the NK-cell tumors limits our ability to standardize the procedures for the diagnosis and clinical management and efforts should be made to encourage multi-institutional registries.

How I treat NK/T-cell lymphomas

Natural killer (NK)/T-cell lymphomas and NK-cell leukemias are aggressive malignancies. Occurring worldwide, they show a predilection for Asian and South American populations. Neoplastic cells are surface CD3-, cytoplasmic CD3ε+, CD56+, cytotoxic-molecule positive, Epstein-Barr virus (EBV) positive, with germline T-cell receptor gene. Lymphomas occur commonly in the nasal and upper aerodigestive region. Occasional cases present in the skin, salivary gland, testis, and gastrointestinal tract. Rare cases are disseminated with lymphadenopathy, hepatosplenomegaly, and a leukemic phase. Positron emission tomography computed tomography is useful in staging, as lymphomas are 18-fluorodeoxyglucose avid. Quantification of circulating EBV DNA is an accurate biomarker of tumor load. Nasal NK/T-cell lymphomas present mostly with stage I/II disease. Concomitant/sequential chemotherapy and radiotherapy is standard treatment. Radiotherapy alone is inadequate because of high systemic failure rate. For stage III/IV nasal, nonnasal, and disseminated lymphomas, systemic chemotherapy is indicated. Regimens containing l-asparaginase and drugs unaffected by P-glycoprotein are most effective. Hematopoietic stem cell transplantation (HSCT) is not indicated for early-stage nasal lymphomas. HSCT for lymphomas not in remission has poor results. In advanced-stage nasal, nonnasal, disseminated, or relapsed lymphomas, HSCT may be considered when remission is achieved. Prognostic modeling and EBV DNA monitoring may be useful in risk stratification for HSCT.

Immunomorphologic profile and Epstein-Barr virus status of a cohort of 35 cases of extranodal natural killer/T-cell lymphoma, nasal type of upper aerodigestive tract from a tertiary care center in South India

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (EN-NK/T-NT) is a lymphoma of NK-cell or cytotoxic T-cell origin, which occurs most commonly in the upper aerodigestive tract. We have studied the immunomorphologic profile and Epstein-Barr virus (EBV) status of a cohort of 35 cases of EN-NK/T-NT of the upper aerodigestive tract (UADT) diagnosed in our institution during the period May 2002 to April 2012. At our institution these lymphomas constitute 0.7% of total non-Hodgkin lymphomas (NHLs) and 5.1% of total peripheral T-cell lymphomas (PTCLs). The median age at diagnosis was 40 years with a male-to-female ratio of 4:1, and the most common site of involvement was the nasal cavity. Morphologically, the neoplastic cells were predominantly medium sized in most cases. Necrosis and angiocentricity were common histologic features. Thirty cases (85.7%) showed NK-cell immunophenotype, CD3+ (29/30, 96.7%), CD56+ (30/30, 100%) and TIA1/Granzyme B+ (30/30, 100%). Five cases (14.3%) showed cytotoxic T-cell immunophenotype, CD3+ (5/5, 100%), CD56- (5/5, 100%) and TIA1/Granzyme B+ (5/5, 100%). EBV-encoded RNA-in situ hybridization (EBER-ISH) was positive in all 35 cases, whereas EBV latent membrane protein-1 (EBVLMP1) was positive in only 19/35 (54.3%) of cases. In conclusion, this is the first large study from India to report the immunomorphologic profile and EBV association of EN-NK/T-NT, which is known to have geographic variation. The frequency of these lymphomas in our study is comparable to that of Western and European countries and much less than that of Far Eastern countries.

Diagnosis and management of rare gastrointestinal lymphomas

Primary gastrointestinal (GI) lymphoma is rare, however accounts for 30-40% of cases of extranodal lymphoma. Several lymphoma subtypes have a propensity for GI tract involvement. Whilst the literature is dominated by data related to the more common extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) and diffuse large B-cell lymphoma (DLBCL) of the stomach, this review focuses on the rare subtypes of enteropathy-associated T-cell lymphoma (EATL), GI follicular lymphoma, mantle cell lymphoma (lymphomatous polyposis coli) and extranodal natural killer (NK)/T-cell lymphoma nasal-type (ENKTL). Due to its rarity, the majority of data regarding primary GI lymphoma have been derived from subgroups of larger cohorts. Clinical characteristics, prognosis and management can differ from those of nodal disease, despite corresponding histology. We discuss these differences and the challenges associated with diagnosis and management of these rare diseases.

Complete remission after first-line radio-chemotherapy as predictor of survival in extranodal NK/T cell lymphoma

Background

Extranodal nasal-type NK/T-cell lymphoma is a rare and severe disease. Considering the rarity of this lymphoma in Europe, we conducted a multicentric retrospective study on nasal-type NK/T cell lymphoma to determine the optimal induction strategy and identify prognostic factors.

Methods

Thirty-six adult patients with nasal-type NK/T-cell lymphoma were recruited and assessed. In total, 80 % of patients were classified as having upper aerodigestive tract NK/T-cell lymphoma (UNKTL) and 20 % extra-upper aerodigestive tract NK/T-cell lymphoma (EUNKTL).

Results

For advanced-stage disease, chemotherapy alone (CT) was the primary treatment (84 % vs. 10 % for combined CT + radiation therapy (RT), respectively), while for early-stage disease, 50 % of patients received the combination of CT + RT and 50 % CT alone. Five-year overall survival (OS) and progression-free survival (PFS) rates were 39 % and 33 %. Complete remission (CR) rates were significantly higher when using CT + RT (90 %) versus CT alone (33 %) (p < 0.0001). For early-stage disease, CR rates were 37 % for CT alone versus 100 % for CT + RT. Quality of response was significantly associated with survival, with 5-year OS being 80 % for CR patients versus 0 % for progressive disease patients (p < 0.01).

Conclusion

Early RT concomitantly or sequentially with CT led to improved patient outcomes, with quality of initial response being the most important prognosticator for 5-year OS.

The diagnosis and management of extranodal NK/T-cell lymphoma, nasal-type and aggressive NK-cell leukemia

Natural killer (NK) cell lymphomas are rare malignancies. They are classified as extranodal NK/T-cell lymphoma, nasal type, and aggressive NK cell leukemia. NK cell neoplasms are prevalent in Asian and South American populations, but are extremely rare in the West. They can be classified clinically into nasal, non-nasal, and aggressive lymphoma/leukemia subtypes. For nasal NK cell lymphomas, combined chemotherapy and radiotherapy are indicated for stage I/II disease. Chemotherapy is the main treatment for stage III/IV nasal NK cell lymphomas, as well as the non-nasal and aggressive subtypes. Regimens containing drugs not affected by the P-glycoprotein, particularly in combination with L-asparaginase, have resulted in much improvement in treatment outcome for high-risk, refractory or relapsed patients. Autologous or allogeneic hematopoietic stem cell transplantation should be considered for selected patients. Epstein-Barr virus DNA load as a surrogate marker for prognostication, and clinical stratification of patients should be incorporated in clinical management algorithms.

Pathobiology of Epstein-Barr virus-driven peripheral T-cell lymphomas

In the present review, the authors described the pathobiological features of Epstein-Barr virus (EBV)-driven T/natural killer cell-derived malignancies. These rare tumors appear to be quite heterogeneous with regard to both clinical and pathologic features. Nonetheless, some elements, especially regarding the possible role of EBV (ie, genomic predisposition, pathogenesis, pattern of latency), are similar, enforcing the concept of a causative role for the virus. In clinical practice, although definitely rare in Western countries, the tumors are not exceptional; thus, they should be taken into account in the differential diagnosis of T-lymphoproliferative disorders, also considering the need for extremely prompt intervention. The prognosis of such tumors is generally poor using current approaches. A better understanding of their molecular pathogenesis may lead to significant therapeutic improvements. For example, the nuclear factor-KB pathway and platelet-derived growth factor receptor inhibition may represent 2 options to be tested in clinical trials.

Diagnosis and management of natural killer-cell malignancies

Natural killer (NK)-cell malignancies are uncommon neoplasms, which have been referred to as polymorphic reticulosis or angiocentric T-cell lymphomas in the past. In the current WHO classification, they are categorized as extranodal NK/T-cell lymphoma, nasal type and aggressive NK-cell leukemia. NK-cell malignancies show a geographical predilection for Asian and South American populations and are rare in the west. Pathologically, NK-cell lymphomas show a polymorphic neoplastic infiltrate with angioinvasion and angiodestruction. The lymphoma cells are CD2(+), cytoplasmic CD3ε(+) and CD56(+), with germline T-cell receptor gene. There is an almost invariable clonal episomal infection with Epstein-Barr virus. Clinically, NK-cell lymphomas can be classified into nasal, non-nasal and aggressive lymphoma/leukemia subtypes. Most nasal NK-cell lymphomas present with stage I/II disease. The early use of radiotherapy, either alone or concomitantly/sequentially with chemotherapy, is the most important factor in achieving successful treatment. Many stage I/II patients receiving radiotherapy alone fail systemically, so the use of chemotherapy is also considered necessary. Chemotherapy is indicated for stage III/IV nasal NK-cell lymphoma, and the non-nasal and aggressive subtypes. Recent regimens that incorporate the use of L-asparaginase have resulted in substantial improvements in outcome in high-risk, refractory or relapsed patients. High-dose chemotherapy and hematopoietic stem-cell transplantation with autologous or allogeneic hematopoietic stem cells may be beneficial to selected patients. Prognostication of patients with clinical prognostic models and presentation circulating Epstein-Barr DNA load may be useful in the stratification of patients for various treatment modalities.

Advances in the management and monitoring of extranodal NK/T-cell lymphoma, nasal type

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, has a unique geographic distribution. Its pathology is characterized by marked angio-invasion and tissue necrosis. A typical NK-cell phenotype is usually present: CD2(+), CD3 epsilon+, CD56(+), cytotoxic molecules+ and Epstein-Barr virus (EBV)+. Magnetic Resonance Imaging helps to clearly define the local involvement. Positron Emission Tomography helps to demonstrate system spread. Various prognostic variables (International Prognostic Index or the Korean Prognostic Index) should be documented. This may include quantification of plasma EBV DNA. For localized nasal disease, radiotherapy is important, although chemotherapy is often added. Sustainable remission is observed in over half of these patients. For extra-nasal or disseminated disease, systemic chemotherapy becomes the mainstay and the prognosis is usually poor. Doxorubicin-containing regimens are not entirely satisfactory and L-asparaginase containing regimens are being investigated. Patients with poor prognostic features may be considered for an early autologous haematopoietic stem cell transplant. Allogeneic transplantation is efficacious but is associated with high transplant-related mortality.

Clinical differences between nasal and extranasal natural killer/T-cell lymphoma: a study of 136 cases from the International Peripheral T-Cell Lymphoma Project

Among 1153 new adult cases of peripheral/T-cell lymphoma from 1990-2002 at 22 centers in 13 countries, 136 cases (11.8%) of extranodal natural killer (NK)/T-cell lymphoma were identified (nasal 68%, extranasal 26%, aggressive/unclassifiable 6%). The disease frequency was higher in Asian than in Western countries and in Continental Asia than in Japan. There were no differences in age, sex, ethnicity, or immunophenotypic profile between the nasal and extranasal cases, but the latter had more adverse clinical features. The median overall survival (OS) was better in nasal compared with the extranasal cases in early- (2.96 vs 0.36 years, P < .001) and late-stage disease (0.8 vs 0.28 years, P = .031). The addition of radiotherapy for early-stage nasal cases yielded survival benefit (P = .045). Among nasal cases, both the International Prognostic Index (P = .006) and Korean NK/T-cell Prognostic Index (P < .001) were prognostic. In addition, Ki67 proliferation greater than 50%, transformed tumor cells greater than 40%, elevated C-reactive protein level (CRP), anemia (< 11 g/dL) and thrombocytopenia (< 150 x 10(9)/L) predicts poorer OS for nasal disease. No histologic or clinical feature was predictive in extranasal disease. We conclude that the clinical features and treatment response of extranasal NK/T-cell lymphoma are different from of those of nasal lymphoma. However, the underlying features responsible for these differences remain to be defined.

Extranodal NK/T-cell lymphoma: diagnosis and treatment cues

Extranodal NK/T-cell lymphoma, nasal type (ENKL) is mostly endemic to East Asia. It predominantly occurs in the nasal or paranasal areas and less frequently in the skin. Most of the tumours show NK-cell, but rarely T-cell, phenotypes. The Epstein-Barr virus (EBV) genome can be usually detected in lymphoma cells. Geographic localization of ENKL matches the endemic distribution of EBV, suggesting that EBV plays an important role in lymphomagenesis. Originally, NK-cell and T-cell types were believed to present the same clinicopathologic characteristics, but recent data suggest more aggressive characteristics for the NK-cell phenotype. Although ENKL is sensitive to radiotherapy, it shows a poorer response to chemotherapeutic agents than other lymphomas due to expression of p-glycoprotein. Therefore, new therapeutic approaches must be considered. Several new clinical trials are now being conducted in East Asia.

Fluorine-18 fluorodeoxyglucose positron emission tomography in mature T-cell and natural killer cell malignancies

Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) is useful in Hodgkin and B-cell lymphomas. Few data exist on T-cell and natural killer (NK)-cell lymphomas. Thirty consecutive T-cell and NK-cell lymphomas were investigated with PET-computerized tomography (CT). In 12 NK-cell lymphomas, all nasal/extranasal lesions were FDG-avid. In nasal/maxillary areas, FDG-avid tumours were consistently more localised than on CT, suggesting that soft tissue masses on CT were partly due to inflammation. These findings have important implications in radiotherapy planning. In two NK-cell lymphomas, PET did not detect morphologically occult marrow infiltration uncovered by in situ hybridisation for Epstein-Barr-virus-encoded small RNA. In angioimmunoblastic lymphoma (n = 7), peripheral T-cell lymphoma, unspecified (PTCL-U, n = 4) and anaplastic large cell lymphoma (ALCL, n = 3), involved nodal/extranodal sites shown on CT and/or biopsy were concordantly PET-positive. In one PTCL-U, PET detected FDG-avid marrow infiltrations not shown on biopsies. In contrast, cutaneous ALCL (n = 1) and mycosis fungoides (n = 2) showed minimal FDG uptake. In one case of T-cell large granular lymphocyte leukaemia, marrow, nodal and bowel infiltrations were not FDG-avid. PET maximum standardised uptake value did not correlate with clinicopathological features and prognosis. These observations defined the pre-treatment value of PET-CT in T-cell and NK-cell lymphomas. The post-treatment role requires further studies.

An extranodal nasal natural killer/T-cell lymphoma with isochromosome 7q10 as the sole cytogenetic aberration was initially diagnosed via bone marrow biopsy

We report a 58-year-old man who presented with fever, pancytopenia, hepatosplenomegaly, and "sinusitis" of his right nostril. Flow cytometric analysis of his bone marrow aspirate revealed a population of cells that were CD56+ (bright), CD2+ (dim), and CD7+ (slight brightly) but negative for CD3, CD4, CD5, CD8, CD11b, CD16, CD57, and T-cell receptors, consistent with aberrant natural killer cells. Bone marrow biopsy showed an atypical lymphoid infiltrate expressing CD56 as well as Epstein-Barr virus- encoded RNA and histiocytic hyperplasia with hemophagocytosis. Subsequent biopsy of his right nasal vestibule demonstrated an atypical lymphoid infiltrate, which was cytoplasmic CD3+, CD56+, and Epstein-Barr virus-encoded RNA positive, consistent with an extranodal nasal natural killer cell lymphoma. Conventional cytogenetic studies of the bone marrow revealed isochromosome 7q10 [i(7)(q10)] as the sole chromosomal aberration. To our knowledge, this is the first report demonstrating i(7)(q10) as a primary cytogenetic abnormality in an extranodal nasal natural killer cell lymphoma.

Effect of positive bone marrow EBV in situ hybridization in staging and survival of localized extranodal natural killer/T-cell lymphoma, nasal-type

PURPOSE

The aim of the study was to determine the effect of EBV-encoded RNA-1 in situ hybridization (EBER-1 ISH) in bone marrow specimens on survival outcome in patients with clinical stage I/II natural killer/T-cell lymphoma.

EXPERIMENTAL DESIGN

We systematically did EBER-1 ISH on 182 archival bone marrow tissues from 91 patients who were diagnosed of stage I/II natural killer/T-cell lymphoma and analyzed the correlation between bone marrow EBER-1 ISH status and survival. We defined minimal bone marrow involvement and definite bone marrow involvement to distinguish the subgroups who revealed EBV-positive cells from normal marrow by EBER-1 ISH from those who showed typical neoplastic cells in bone marrow biopsies.

RESULTS

In total, 17 of the 91 (18.7%) patients showed positivity for EBER-1 ISH at least in one of the bilateral bone marrow biopsies with 14 minimal bone marrow involvements and 3 definite bone marrow involvements. Patients with positive bone marrow EBER-1 ISH showed significantly poorer overall survival than those who were negative for bone marrow EBER-1 ISH (median survival, 16.1 months versus not reached; P = 0.045).

CONCLUSION

Considering a high proportion of stage I/II patients (15.4%) with minimal in bone marrow specimens, bone marrow EBER-1 ISH should be routinely done in all patients with localized disease for more accurate staging.

Successful Treatment of Advanced Extranodal NK/T Cell Lymphoma with Unrelated Cord Blood Transplantation

Nasal natural killer (NK)/T cell lymphoma is a rare entity of non-Hodgkin's lymphoma which mostly occurs in East Asian countries. The advanced disease above clinical stage III is often refractory to the radiation and chemotherapies, remission is transient even if achieved, and median survival is about 12 months. Thus the prognosis of advanced NK/T cell lymphoma is generally poor, however, the promising results of allogeneic hematopoietic stem cell transplantation for advanced NK/T cell lymphoma have been recently reported. In most of these cases, stem cell sources were human leukocyte antigen (HLA) matched donors and alternative sources were seldom used. We report here a case of a 36-year-old woman who was diagnosed as having an extranodal NK/T cell lymphoma, nasal type. The patient achieved a complete remission after 2 cycles of chemotherapy including Carboplatin, Etoposide, Ifosfamide, and Dexamethasone, but 3-months later relapsed during the search for HLA-matched unrelated donors. She received unrelated cord blood transplantation (CBT) in the second remission achieved by a regimen containing L-asparaginase. The conditioning regimen was 12 Gy of total body irradiation, high-dose cytarabin and cyclophosphamide. FK506 and methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. GVHD involving the intestine and the oral mucosa was observed, but improved without additional immunosuppressive therapies. The patient remains in remission 33 months after CBT. Cord blood thus could be an appropriate stem cell source for patients with advanced NK/T lymphoma who have no HLA matched donors.

Optimal processing of bone marrow trephine biopsy: the Hammersmith Protocol

Specimens of bone marrow trephine biopsy (BMT) are transported and fixed in acetic acid-zinc-formalin fixative, decalcified in 10% formic acid-5% formaldehyde and processed with other specimens to paraffin-wax embedding. Sections, 1-microm-thick, are cut by experienced histotechnologists and used for haematoxylin and eosin, Giemsa, reticulin silver and other histological stains. Further, all immunohistochemical procedures used in the laboratory, including double immunostaining, can be used on these sections with no or minimal modifications. About 10,000 BMT specimens have been analysed using this procedure since 1997 and diseases involving the bone marrow have been classified successfully. More recently, standardised polymerase chain reaction-based analysis and mRNA in situ hybridisation studies have been conducted. Excellent morphology with good antigen, DNA and RNA preservation is offered by the Hammersmith Protocol.

Natural killer-cell malignancies: diagnosis and treatment

Natural killer (NK)-cell malignancies are uncommon diseases. Previously known as polymorphic reticulosis or angiocentric T-cell lymphomas, they are classified by the World Health Organization as NK/T-cell lymphoma, nasal type and aggressive NK-cell leukemia. They are prevalent in Asia and South America, but exceptionally rare in western countries. Pathologically, NK-cell lymphomas show a polymorphic neoplastic infiltrate with an angioinvasive and angiodestructive pattern. Lymphoma cells are characteristically CD2+, CD56+ and cytoplasmic CD3epsilon+. T-cell receptor gene is germline, and clonal Epstein-Barr virus (EBV) infection is almost invariably. Clinically, they can be divided into nasal, non-nasal, and aggressive lymphoma/leukemia subtypes. Most nasal NK-cell lymphomas present with stage I/II disease, and frontline radiotherapy is the most important key to successful treatment. Many stage I/II patients treated with radiotherapy fail systemically, implying that concomitant chemotherapy may be needed. Chemotherapy is indicated for advanced nasal NK-cell lymphoma, and the non-nasal and aggressive subtypes. However, treatment results are unsatisfactory. High-dose chemotherapy with hematopoietic stem cell transplantation may be beneficial to selected patients. The International Prognostic Index and presentation EBV DNA load is of prognostic significance and may be useful in the stratification of patients for various treatment modalities.

Diagnostic cues for natural killer cell lymphoma: primary nodal presentation and the role of in situ hybridisation for Epstein-Barr virus encoded early small RNA in detecting occult bone marrow involvement

Natural killer (NK) cell lymphomas are rare, and atypical features might lead to diagnostic pitfalls. This report describes an unusual patient in whom lymphoma occurred initially as isolated lymph node involvement, an exceptional presentation of an almost exclusively extranodal disease. Furthermore, during the terminal haemophagocytosis in the bone marrow, lymphoma cells lost the expression of the NK cell marker, CD56, making the histopathological diagnosis of bone marrow involvement difficult. This was resolved by in situ hybridisation for Epstein-Barr virus encoded small RNA, which detected occult bone marrow infiltration.

Bone marrow histopathology in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCL) account for 10-15% of all lymphoproliferative disorders in the western hemisphere. In PTCL, bone marrow biopsy is performed to establish the diagnosis, rule out other pathology, assess the extent of disease and monitor treatment response. The frequency and histology of bone marrow involvement varies greatly between different clinicopathological entities recognized by the World Health Organisation (WHO) classification, reflecting the differences in the underlying biology. Some lymphomas, such as angioimmunoblastic T-cell lymphoma, show nodular and/or interstitial pattern of infiltration with accompanying reactive changes. Others, including hepatosplenic T-cell lymphoma and large granular lymphocyte leukaemia, are characterized by intrasinusoidal infiltration. In many instances the pathological features are subtle and immunohistochemical and molecular studies are required for the diagnosis. Histological appearances may overlap with a variety of reactive T-cell proliferations and other malignancies. Furthermore PTCL frequently induce secondary changes in the marrow that may obscure the neoplastic infiltrate. The diagnosis often requires critical integration of the information obtained from clinical features, peripheral blood, bone marrow aspirate and biopsy findings. In this article we review the histopathology of bone marrow biopsy in PTCL within the context of the new WHO classification.

Bone marrow is involved in less than 10% of patients with nasal-type NK/T cell lymphoma at initial diagnosis

To evaluate the frequency of bone marrow involvement by nasal-type NK/T cell lymphoma, we retrospectively studied biopsy specimens from 40 patients by EBV in situ hybridization (ISH). Three patients had marrow involvement at initial diagnosis (7.5%). In one patient (1/40, 2.5%), the disease in bone marrow was recognized by routine morphological assessment, while two other patients had minimal involvement of lymphoma cells which was recognized only by EBV in situ hybridization (2/40, 5%). Two patients had a disseminated disease at diagnosis and died 6 days and 214 days after diagnosis. One patient had diffuse colonic lesion and died 82 days later. In conclusion, marrow involvement in nasal NK/T cell lymphoma is infrequent at initial diagnosis, and EBV ISH is a useful technique for identifying the minor subgroup of patients which have easily overlooked neoplastic involvement.

Autologous stem cell transplantation for nasal NK/T-cell lymphoma: a progress report on its value

Nasal NK/T-cell lymphoma is an Epstein-Barr virus-related, highly aggressive but localized disease in Orientals. The median survival is <1 year. Here, we update our experience on 18 patients treated with autologous stem cell transplantation (ASCT). Two patients died of mucositis and septicemia during ASCT. Relapse occurred in nine cases, including six local relapses. Compared with patients treated in remission, all patients treated in active or disseminated disease died of early relapse. Within this cohort, there was no significant survival difference between patients treated in first (CR1, n = 7) or second (CR2, n = 5) complete remissions. However, among consecutive cases analyzed, the patients receiving ASCT at CR1 showed a trend towards better overall survival compared with historical matched controls (P = 0.064). Disease relapse beyond 6 months was not seen after ASCT. Our retrospective data suggest that ASCT in CR1 is a viable consolidation therapy for local-stage NK/T lymphoma, but a randomized trial is needed to prove any definite survival benefit. For patients with relapsed, refractory or extranasal disease, early consideration for allogeneic transplantation and alternative therapy may be warranted.