Clinicopathologic study of CD56 (NCAM)-positive angiocentric lymphoma occurring in sites other than the upper and lower respiratory tract

Epstein-Barr virus-associated T/natural killer-cell lymphomas in the elderly: the first consensus meeting in Kofu 2013

From a clinicopathological conference on nine elderly patients with Epstein-Barr virus (EBV)-associated T/natural killer (NK)-cell lymphoma, we have addressed the patients' backgrounds, clinical manifestations, histopathological findings, cytogenesis, complications and prognoses. Among these elderly patients (>65 years old), seven patients had extranodal NK/T-cell lymphoma, nasal type (ENKL) with an NK-cell phenotype, and two patients had EBV(+) T-cell lymphomas or lymphoproliferative disorders (LPD) with cutaneous lesions mimicking pityriasis lichenoides et varioliformis acuta (PLEVA) or hydroa vacciniforme (HV). No patients had a previous episode of EBV-related symptoms such as infectious mononucleosis, chronic active EBV infection, HV or hypersensitivity to mosquito bites. Elderly patients with ENKL may show the centroblastoid variant. EBV(+) CD8(+) CD56(+/-) lymphocytes may be responsible for the development of PLEVA or HV-like cutaneous lesions in the elderly.

Abnormal immunophenotype provides a key diagnostic marker: a report of 29 cases of de novo aggressive natural killer cell leukemia

Aggressive natural killer (NK) cell leukemia (ANKL) is a systemic neoplastic proliferation of NK cells with an aggressive clinical course. Currently, the diagnosis of ANKL remains challenging. In the current study, we report the clinical, laboratory, immunophenotypic, and genetic findings from 29 cases of de novo ANKL in a single center and evaluate the relative contribution of these features to the diagnosis of ANKL. Clinical features, laboratory findings, morphologic, cytogenetic features, and Epstein-Barr virus status were important factors for diagnosing aggressive NK cell leukemia. On the other hand, ANKL displays a strikingly abnormal immunophenotype in contrast to nonneoplastic NK cells. The immunophenotype of ANKL cells may differ from reactive NK cells in 4 respects. First, the CD45/linear side scatter gating of flow cytometry allows the initial identification of neoplastic subpopulations for additional immunophenotypic analysis in half of ANKL cases. Second, unusual expression of surface antigens in ANKL cells was a prominent feature. Third, the clonality of ANKL cells could be identified using antibodies against CD158a/h, CD158b, or CD158e. Last, the positive rate of Ki-67 expression in ANKL cells was generally high. Based on these findings, we provide an objective marker based on clinical data for the definite diagnosis of ANKL.

NK-cell neoplasms in Japan

Neoplasms putatively originating from precursor and mature natural killer (NK) cells are rare, and their clinical features are unclear. A nationwide survey was performed in Japan to clarify the clinical features of these neoplasms diagnosed between 1994 and 1998, and data for 237 patients who met the criteria for putative NK cell-lineage neoplasms were analyzed. Among them, 11 had myeloid/NK-cell precursor acute leukemia, 15 blastic NK-cell lymphoma, 21 precursor NK-cell acute lymphoblastic leukemia, 22 aggressive NK-cell leukemia/lymphoma, 149 nasal-type NK-cell lymphoma (123 nasal and 26 extranasal) and 19 chronic NK lymphocytosis. The median overall survival time of patients with aggressive NK-cell leukemia/lymphoma was 2 months, which for chronic NK lymphocytosis was more than 8 years, and that for the other types of NK-cell neoplasms was between 6 and 22 months. Nasal NK-cell lymphoma and extranasal NK-cell lymphoma share the same histology. The age of affliction was the same, but the sex was different with males predominantly having nasal NK-cell lymphoma and females extranasal NK-cell lymphoma. Patients with extranasal NK-cell lymphoma had the tendency to exhibit a more advanced state of disease, with significantly higher International Prognostic Index and LDH levels, and significantly lower hemoglobin and platelet levels. The overall survival, however, did not differ significantly. Precursor NK-cell acute lymphoblastic leukemia and blastic NK-cell lymphoma were arbitrarily defined by the presence or absence of 30% or more of blastic cells in the bone marrow or peripheral blood, but there were no significant differences for affected age, gender, involved sites or prognosis. Aggressive NK-cell leukemia/lymphoma and extranasal NK-cell lymphoma were arbitrarily defined by the presence or absence of 30% or more of large granular lymphocytes in the bone marrow or peripheral blood and it is possible that aggressive NK-cell leukemia/lymphoma is a leukemic phase of extranasal NK-cell lymphoma. The incidence of skin involvement, however, was significantly higher for extranasal NK-cell lymphoma, suggesting that the two diseases are different. In nasal NK-cell lymphoma, Epstein-Barr virus in tumor cells was detected in all patients tested, suggesting its causative role.

Intraocular involvement of a nasal natural killer T-cell lymphoma: a case report

Herein, we report a case of nasal natural killer T-cell lymphoma (NKTL) with intraocular involvement. A 57-year-old woman was referred due to a three-day history of photophobia and diplopia in the left eye. One-month previously, she was diagnosed with nasal NKTL of the right nasal cavity. Ophthalmic examination revealed conjunctival injection and ptosis. The left pupil was fully dilated and non-reactive to light. Ocular motion was restricted on left-upper gaze. Five days later, anterior uveitis developed and persisted despite topical steroid treatment. An orbital magnetic resonance imaging was without specific findings, however, ophthalmoplegia, vitreous opacity, and an iris mass were observed. A diagnostic anterior chamber aspiration was performed. Aqueous humor aspiration revealed 35% morphologically atypical lymphocytes. After an intravitreal triamcinolone injection, radiotherapy and chemotherapy were administered; this resolved the uveitis and iris mass. When refractory uveitis or orbital pseudotumor occurs in patients with nasal NKTL, ocular and orbital involvement of the NKTL should be considered.

Successful salvage treatment of blastic natural killer cell lymphoma with methotrexate

A 69-year-old man with blastic natural killer cell lymphoma (BNKL) was treated mainly with methotrexate (MTX). He presented with skin and bone marrow involvement at onset. Neoplastic cells were blastic in appearance with CD3-, CD4-, CD8-, CD7-, CD16-, CD56+ and HLA-DR+ phenotype. Molecular studies showed germline configuration of both immunoglobulin H and T cell receptor genes, and negative results for Epstein-Barr virus-encoded small RNA (EBER). He was treated with standard acute lymphoblastic leukemia (ALL) induction therapy, followed by 1 cycle of high-dose MTX (HD-MTX) as consolidation therapy. However, BNKL relapsed during standard ALL maintenance therapy. Three cycles of HD-MTX were effective in achieving a second complete remission and then he received low dose MTX as maintenance therapy. BNKL remained well controlled for 4 years. Chemotherapeutic toxicity was mild and manageable. Since BNKL reportedly has a poor prognosis, this encouraging result warrants further investigation of MTX as either a single agent or in a combination regimen as a first-line treatment for patients with BNKL.

Expression of the metalloproteases MMP-1, MMP-2, MMP-3, MMP-9, MMP-11, TIMP-1 and TIMP-2 in angiocentric midfacial lymphomas

Background

Extranodal T/NK cell lymphomas possess distinctive clinico-pathological characteristics: they are angiocentric, exhibit extensive necrosis. Prognosis is poor in the short term. The objective is to explore the expression of different MMPs in the cells and stroma which are around of the blood vessels damaged and their correlation with clinico-pathological parameters.

Patients and methods

Twenty cases of this type of lymphomas were studied and collected patient clinical data. The expressions of MMP-1, 2, 3, 9, 11, 13 and TIMP-1, 2 were studied by immunohistochemistry. Ultrastructural studies were performed in two cases. Statistical analysis was done with Fisher's exact test, Chi² test.

Results

Of the 20 patients, 13 were men with median age of 43 years. In 13 patients the primary tumor was localized in the nasal cavity. Treatment was combined chemotherapy and radiotherapy in 60%. The 55% advanced clinical stages, 70% died from the disease. There were neoplastic cell and peritumoral fibroblasts positivity to MMP-1 and MMP-11 in most of the cases. The MMPs-2, 3 and 9 were expressed in neoplastic cell between 30 to 65%of the cases. TIMP-1 was presented mainly in the epithelium and TIMP-2 was poor expressed of the all cases.

Conclusion

There were no statistical significance between the different enzymes used and the clinical parameters, besides status and survival of the patients. It is necessary to study more enzymes and focus them to quantify and determine their activity, in order to have a better correlation with histological features in this type of neoplasm.

The value of [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography in extranodal natural killer/T-cell lymphoma

PURPOSE

To our knowledge, there are no published data pertinent to the use of [(18F)]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with natural killer (NK)/T-cell lymphoma. The purpose of this study was to assess the value of FDG PET/CT in this aggressive type of non-Hodgkin lymphoma.

PATIENTS AND METHODS

All patients with NK/T-cell lymphoma referred for FDG PET/CT at our institution from July 2001 to July 2006 were retrospectively studied. PET/CT examinations were blindly reviewed by 2 experienced readers. The results were compared with the status of the disease, which was determined after evaluation of biopsy, laboratory, clinical and conventional imaging examination, and follow-up results. PET/CT results were thereby classified as true-positive, true-negative, false-positive, or false-negative. The degree of FDG uptake in the positive lesions was semiquantified using maximum standard uptake value (SUV(max)).

RESULTS

Twenty-one PET/CT examinations were performed in 10 patients with NK/T-cell lymphoma. For nasal disease, PET/CT was true-positive in 5 cases, true-negative in 15 cases, and positive but unconfirmed in 1 case. For extranasal disease, PET/CT was true-positive in 3 cases, true-negative in 16 cases, and false-negative in 2 cases. The mean SUV(max) in PET-positive lesions in nasal cavities or paranasal sinuses was 16 gm/mL (range, 5-25 gm/mL; median, 19.3 gm/mL). In extranasal disease, the mean SUV(max) was 10.9 gm/mL (range, 4.6-34.1 gm/mL; median, 5.6 gm/mL).

CONCLUSION

Viable NK/T-cell lymphoma is intensely FDG hypermetabolic. PET/CT appears to be sensitive for the detection of disease in the nasopharynx and, to a lesser extent, in extranasal sites.

Intestinal T-cell and natural killer-cell lymphomas in Taiwan with special emphasis on 2 distinct cellular types: natural killer-like cytotoxic T cell and true natural killer cell

Primary intestinal lymphomas are rare, especially the T-cell and natural killer (NK)-cell types. Enteropathy-type T-cell lymphoma (ETL) is the most characteristic of the intestinal T-cell and NK-cell lymphomas (ITNKLs) defined in the World Health Organization classification. However, typical ETL is rare in nonendemic areas for celiac disease, which include Taiwan. With the exception of ETLs, ITNKLs comprise heterogeneous subtypes such as anaplastic large cell lymphoma, nasal-type NK/T-cell lymphoma and peripheral T-cell lymphoma, unspecified. Furthermore, the literature results with respect to the association between Epstein-Barr virus (EBV) and ITNKL are contradictory. To define the clinicopathological features of primary ITNKLs and develop a better understanding of their relationship with EBV in Taiwan, therefore, we investigated a sample of 11 patients based on the new World Health Organization classification using immunostaining, in situ hybridization for EBV detection, and polymerase chain reaction (PCR) for evaluation of T-cell receptor clonality. In conclusion, 2 distinct groups of primary ITNKLs were identified in our Taiwanese sample. The 6 group A cases were non-EBV-associated ETLs, prevalent in the jejunum and/or ileum. They were composed of monotonous round-ovoid medium-sized nuclei and had little pale cytoplasm. The immunophenotypes of these tumors were consistently CD3+, CD4-, CD8+, CD56+, T-cell intracellular antigen 1+, and Epstein-Barr early region- and monoclonal for T-cell receptor PCR, which indicated NK-like cytotoxic T-cell origin. The 5 group B cases were EBV-associated nasal-type NK/T-cell lymphomas prevalent in the ileum or cecum of younger patients. The neoplastic cells had polymorphous medium to large angulated nuclei and moderate cytoplasm, with immunologic phenotypes of CD4-, CD8-, variable cytoplasmic CD3varepsilon+, CD56+, T-cell intracellular antigen 1+, and Epstein-Barr early region 1+, and germ line PCR result for T-cell receptor, which indicated true NK-cell origin. The grave prognoses for the 2 groups did not differ significantly.

Precursor natural killer cell leukemia

Natural killer (NK) cell tumors are a rare and heterogeneous group of disorders. Immature NK cell tumors are less common, and are less recognized and defined than mature NK cell tumors. There is insufficient experience of diagnosis and treatment with immature NK cell tumors, especially in pediatric patients. Here we describe a pediatric patient with precursor NK cell leukemia and review the literature of the previously reported cases in children to further help characterize the diagnosis, treatment, and outcome.

Plasmacytoid dendritic cell leukaemia/lymphoma: towards a well defined entity?

CD4(+)/CD56(+) haematodermic neoplasm or 'early' plasmacytoid dendritic cell leukaemia/lymphoma (pDCL) was described as a disease entity in the last World Health Organisation/European Organisation for Research and Treatment of Cancer classification for cutaneous lymphomas. These leukaemia/lymphomas co-express CD4 and CD56 without any other lineage-specific markers and have been identified as arising from plasmacytoid dendritic cells. Despite a fairly homogeneous pattern of markers expressed by most pDCL, numerous distinctive features (e.g. cytological aspects and aberrant marker expression) have been reported. This may be related to the 'lineage-independent developmental' programme of dendritic cells, which may be able to develop from either immature or already committed haematopoietic progenitors. This highlights the need for specific validated markers to diagnose such aggressive leukaemia. Here, we propose--among others (e.g. T-cell leukaemia 1)--blood dendritic cell antigen-2 and high levels of CD123 expression as potential markers. In addition, we propose a multidisciplinary approach including several fields of haematology to improve pDCL diagnosis.

Periphere NK/T-Zell-Lymphome

Peripheral T-cell lymphomas comprise 8% of the malignant lymphomas in Germany. About 25% of these cases present primarily in extranodal localizations. Such localizations are typical for the respective disease and form the basis for the classification of extranodal peripheral T-cell lymphoma. The morphology, immunophenotype and lineage specificity of the tumor cells (originating from T- or NK-cells) is only secondary for the classification. Extranodal NK/T-cell lymphomas of the nasal type are characterized by an angiocentric growth pattern and large confluent areas of necrosis. In addition, there is a clonal infection by Epstein-Barr virus in the T-lymphocytes. In the differential diagnosis, B-cell lymphomas are more frequent at all localizations than T- or NK-cell lymphomas.

Pediatric CD56+ anaplastic large cell lymphoma: a review of the literature

CONTEXT

Anaplastic large cell lymphomas (ALCLs) are a heterogeneous group of CD30+ large cell lymphomas that, according to the World Health Organization classification, are defined as being of T-cell origin, based on immunophenotype, and/or the finding of a T-cell gene rearrangement by molecular studies. Most cases express cytotoxic granule-associated proteins. Relatively recent data have suggested that some T-cell ALCLs are derived from cytolytic CD4+ cells, gammadelta T cells, or natural killer-like (CD56+ or CD57+) T cells. We encountered a pediatric case of CD56+, anaplastic lymphoma kinase-positive ALCL of apparent natural killer-like T-cell origin (showing positivity for CD2, cytoplasmic CD3, surface CD3 partial positivity, CD7, CD8, CD56, TIA-1, and granzyme B). The patient had initial lymph node and multiple sites of cutaneous involvement and an aggressive clinical course with multiple recurrences after varying periods of complete remission.

OBJECTIVE

To review the current pediatric literature regarding the incidence, differential diagnosis, and clinical course of such cases.

DATA SOURCES

Relevant articles indexed in PubMed (National Library of Medicine) between 1975 and 2006.

CONCLUSIONS

Our review did not confirm a uniformly aggressive clinical course in pediatric cases of CD56+ ALCLs. Such cases suggest the usefulness of the analysis of CD56-positivity in additional cases of ALCL in an attempt to accrue additional information on this condition. Future accrual of such cases may address whether such cases should be treated more aggressively or with possible targeted therapeutic regimens.

CD56-positive haematological neoplasms of the skin: a multicentre study of the Cutaneous Lymphoma Project Group of the European Organisation for Research and Treatment of Cancer

BACKGROUND

Cutaneous lymphomas expressing CD56, a neural cell adhesion molecule, are characterised in most cases by a highly aggressive clinical course and a poor prognosis. However, prognostic subsets within the CD56+ group have been difficult to identify due to the lack of uniform clinicopathological and immunophenotypical criteria.

METHODS

A multicentre study was conducted by the Cutaneous Lymphoma Task Force of the European Organisation for Research and Treatment of Cancer to define prognostic parameters and establish diagnostic and therapeutic guidelines for CD56+ haematological neoplasms presenting primarily in the skin.

RESULTS

Four different subtypes of lymphoproliferations with CD56 expression were identified: (1) haematodermic neoplasm; (2) skin infiltration as the first manifestation of CD56+ acute myeloid leukaemia; (3) nasal-type extranodal natural killer/T-cell lymphoma; and (4) "classical" cases of cutaneous T-cell lymphoma (CTCL) with co-expression of the CD56 molecule. Patients in the first three groups had a poor outcome (93% died) with a median survival rate of 11 months (95% CI 2-72 months), whereas all patients with CD56+ CTCL were alive at the last follow-up.

CONCLUSION

Results show that CD56+ cutaneous lymphoproliferative disorders, with the exception of CD56+ CTCL have a very poor prognosis. It is therefore clinically important to separate CD56+ CTCL from the remaining CD56+ haematological disorders.

Extranodal lymphomas of the head and neck

Malignant lymphomas represent approximately 5% of all malignant neoplasms of the head and neck and may involve nodal or extranodal sites. Nodal head and neck lymphomas are similar to other nodal sites and are not further reviewed here. The head and neck region is the second most frequent anatomical site of extranodal lymphomas (after the gastrointestinal tract). Most are non-Hodgkin's lymphomas of B-cell lineage, and overall diffuse large B-cell lymphoma is the most common type. Hodgkin's lymphoma rarely occurs in extranodal sites. Other hematologic neoplasms that commonly involve extranodal sites of the head and neck are also discussed. In this review, we begin by discussing lymphomas involving the head and neck according to anatomical site. Then we discuss specifically the pathological findings of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, plasmablastic lymphoma, extramedullary plasmacytoma, and extranodal natural killer/T-cell lymphoma of nasal type.

Natural killer/T-cell lymphoma with ocular and adnexal involvement

PURPOSE

To review the clinical, radiological, and histopathologic features in 8 patients with natural killer/T-cell lymphoma (NKTL) involving the orbit and/or ocular adnexa, and to describe the responses of these patients to various treatment regimens.

DESIGN

Retrospective observational case series.

PARTICIPANTS

Eight patients (5 male, 3 female) with NKTL involving the orbit and/or ocular adnexa were identified from 1999 through 2005. The mean age at presentation was 45 years (range, 26-65).

METHODS

We retrospectively identified patients with NKTL of the ocular adnexa treated in the authors' medical centers from 1999 through 2004 using computerized diagnostic index retrieval. The clinical records and radiologic studies were analyzed to define modes of presentation and progression, response to therapy, and areas of anatomic involvement. Histopathologic findings, including the presence of CD3, CD56, and Epstein-Barr virus-encoded mRNA in each patient, were reviewed.

MAIN OUTCOME MEASUREMENTS

Time of survival from presentation to last known follow-up and tumor-related death.

RESULTS

Four of the 8 patients (50%) with NKTL involving the orbit or ocular adnexa had systemic involvement at presentation. Five of the 8 patients (62.5%) had concurrent sinonasal involvement, whereas 3 (37.5%) had orbital involvement alone. All lesions demonstrated CD3, CD56, and/or Epstein-Barr virus positivity on immunopathology studies. Therapy consisted of various chemotherapeutic regimens typically employed in the treatment of non-Hodgkins lymphoma, steroids, surgical intervention, and radiation. Seven (87.5%) patients died 5 weeks to 13 months after presentation, and 1 (12.5%) is alive without disease (5-year follow-up).

CONCLUSIONS

Natural killer/T-cell orbital lymphoma is a rare Epstein-Barr virus-associated neoplasm that may occur with or without associated sinonasal involvement. Our series, the largest cohort reported to date, demonstrates the high lethality of this condition despite aggressive conventional therapy, suggesting that new treatment options should be considered early in the course of treatment of patients with this disorder.

CD56/NCAM-positive Langerhans cell sarcoma: a clinicopathologic study of 4 cases

This report concerns the clinicopathologic features of 4 patients with CD56/neural cell adhesion molecule (NCAM)-positive Langerhans cell sarcoma (LCS). Three of the patients were elderly, between 59 and 62 years of age at presentation, and the other was 35 years old. The presenting symptoms included fever, bone pain, and weakness. The patients shared some clinical findings, such as multiorgan involvement of lymph nodes, skin, lung, bone marrow, and spleen. LCS carries a poor prognosis, and 3 of the patients died of the disease within several years of presentation despite multiagent chemotherapy and radiotherapy. Of special interest is that all of the cases showed CD56 expression on the tumor cells in addition to expression of CD1a, S100beta, and langerin, the presence of which suggests derivation from Langerhans cells. For control, CD56 was also examined in 8 cases of Langerhans cell histiocytosis (LCH), a single-system unifocal or multifocal disease, and the results of staining of the tumor cells were negative. Our findings indicated that CD56 may be a clinically relevant biologic marker for predicting an intractable course of Langerhans cell neoplasms, although it is often difficult to draw a definite morphologically-based distinction between LCS and LCH.

Extranodal nasal type NK/T-cell Lymphoma: Elucidating clinical prognostic factors for risk-based stratification of therapy

The purpose of this study was to define distinctive clinical features of "nasal" and "nasal-type" NK/T cell lymphomas by assessing prognostic factors. The anatomic definition of extranasal NK/T cell lymphoma has been vague resulting in variable definitions of extranasal sites by different groups. We analysed the clinical behavior of 90 NK/T cell lymphoma patients and attempted to elucidate the prognostic factors for risk-based stratification of therapy. We observed no significant difference between "nasal" and "nasal-type" NK/T cell lymphomas in regards to clinical features and survival using the conventional anatomic classification. We suggest the categorisation of the two subtypes of NK/T cell lymphoma as follows: UNKTL (upper aerodigestive tract NK/T cell lymphoma) including all lymphomas confined to nasal cavity, nasopharynx, and the upper aerodigestive tract and EUNKTL (extra-upper aerodigestive tract NK/T cell lymphoma) group to include all sites other than the UNKTL group. The EUNKTL group in this study had advanced stage at diagnosis, higher LDH, higher IPI score, poorer performance and inferior response to the anthracycline-based chemotherapy with statistical significance. There was a significant difference in survival rate between EUNKTL and UNKTL group (20.0%, 54.0%, respectively, P = 0.0068). More aggressive treatment should be sought for this particular group of patients for EUNKTL patients.

Nasal-type NK/T cell lymphoma: clinical features and treatment outcome

Nasal-type NK/T cell lymphoma is an increasingly recognised disease entity of aggressive clinical behaviour. The objective of this study was to investigate clinical features and treatment outcomes in patients with nasal-type NK/T cell lymphoma. From January 1991 to December 2003, 26 patients diagnosed as nasal-type NK/T cell lymphoma were included in the analysis. One half of patients presented with poor performance status (ECOG ⩾2); 46% of patients were categorised as high intermediate or high-risk group according to IPI; and 46% of patients were diagnosed at advanced stage. The median survival for 26 patients with nasal-type NK/T cell lymphoma was 7.4 months (95% CI, 0.1, 16.9). The treatment outcome of primary anthracycline-based chemotherapy was poor: 60% CR rate in localised disease and 0% CR rate in advanced disease. After a median follow-up of 24.4 months (range 3.1–99.0) in patients with localised disease who had achieved a CR (range 29.6–165.7), three patients (50.0%) developed disease recurrence at 6.1, 21.8, and 52.1 months, respectively, and all patients presented with locoregional failure. The predictive factors for poor survival were of age greater than 60, advanced stage and poor performance in multivariate analysis. In conclusion, Nasal-type NK/T cell lymphomas showed a poor response to the conventional anthracycline-based chemotherapy, and thus an investigation for an innovative therapy is urgently needed to improve survival in these patients.

Aggressive Natural Killer-Cell Leukemia: report of five cases and review of the literature

We report 5 cases of Aggressive Natural Killer-Cell Leukemia (ANKL) diagnosed and treated in our institution within a period of 5 years. Presented are the clinical, hematological, immunophenotypic, immunogenotypic and cytogenetic data. ANKL is a very rare disorder. On review of the English-language literature only 68 published cases were identified. Analysis was performed on a total number of 73 cases (68 from the literature and the series of 5 presented hereby). Presented and discussed are the epidemiology, clinical picture, morphology, cell marker, immunogenotype, cytogenetics, and survival data of the analysis, as well as the associations with the Epstein-Barr virus (EBV). To our knowledge this is the largest series of cases of ANKL analyzed and therefore it is hoped to contribute towards a better characterization of the disorder.

An unusual case of peripheral T-cell lymphoma with CD56 positivity and angiocentric, angiodestructive morphology arising in the ileum

Natural killer cell and cytotoxic T-cell lymphomas are frequently difficult to distinguish because they share many common features, and yet it is important to make an accurate diagnosis because their prognoses differ. We report an unusual case of a white man with a CD56-positive T-cell lymphoma in the ileum. The histologic pattern was characterized by angioinvasion and angiodestruction. Immunohistochemical staining showed positive reactions to CD3, CD8, CD43, CD45RO, CD56, and T-cell intracellular antigen-1, but negative reactions to CD4, CD5, CD20, CD23, and CD57. Epstein-Barr virus (EBV) was not detected by EBV-latent membrane protein staining and EBV polymerase chain reaction technique. The T-cell receptor gamma chain gene was rearranged. According to the World Health Organization classification, the absence of EBV excludes the diagnosis of extranodal natural killer/T-cell lymphoma, nasal type. However, the association of EBV with this lymphoma in white patients is not clear. Therefore, absence of EBV alone does not necessarily exclude nasal-type natural killer/T-cell lymphoma, particularly because the histologic pattern in this case is highly characteristic of this tumor.

Remission of natural-killer cell lymphoma of the liver with anti-hepatitis C therapy

Non-Hodgkin lymphomas (NHL) consist of a diverse group of lymphoproliferative neoplasms with unique patterns of biology, behavior, and differing responses to therapy. A rare subtype of malignancy arising from cells of putative natural killer (NK) origin is being recognized as a distinct clinicopathological entity. Viruses including hepatitis C have been reported in association with various types of NHL but not the NK-cell subtype. We hereby report a unique case of a patient with hepatitis C who developed hepatic NK-cell lymphoma and chronic NK-cell leukemia. Interestingly, we observed clinical and radiologic remission of the neoplasm following treatment with anti-hepatitis C therapy.

Blastic natural killer cell lymphoma/leukemia (CD56-positive blastic tumor)

BACKGROUND

Blastic natural killer (NK) cell lymphoma/leukemia (BNKL) is an immature CD56-positive neoplasm, which was recognized recently and characterized by systemic proliferation of tumor cells including skin, lymph node, and bone marrow.

METHODS

The current study analyzed 47 patients with BNKL (27 had leukemias and 20 had lymphomas). Patient data were collected for the survey of the NK-Cell Tumor Study Group.

RESULTS

There were 33 males and 14 females, with a median age of 53 years (range, 3 months to 89 years). There were few clinicopathologic differences between the leukemia and lymphoma types. Cutaneous involvement was noted at diagnosis in 28 patients, who presented a tendency for older age of onset (median: 56 vs. 46 years, P = 0.11) than patients with noncutaneous BNKL. Cutaneous BNKL showed less frequent mediastinal involvement (4% vs. 53%, P = 0.0002) and less severe thrombocytopenia (P =0 .03). Phenotypic characteristics were also different, with cutaneous BNKL favoring CD4 and HLA-DR expression, and noncutaneous BNKL favoring CD16 and CD34 expression. Both groups responded well to chemotherapy for lymphoid malignancies, but disease recurrence was frequent. The prognosis of patients with noncutaneous BNKL was significantly poorer than that of patients with cutaneous BNKL (median survival: 15 vs. 25 months, P = 0.02). Multivariate analysis confirmed that cutaneous involvement was a significant and independent prognostic factor for BNKL, as were age of onset and leukocyte count.

CONCLUSIONS

These findings suggested that BNKL is a heterogeneous disease and contains at least two subtypes. Although further investigations are needed to settle a marker for distinction, the presence of cutaneous involvement is a useful prognostic factor.

Nasal-type extranodal natural killer/T-cell lymphomas: a clinicopathologic and genotypic study of 42 cases in Singapore

We studied the clinicopathologic features of 42 cases of nasal-type extranodal natural killer (NK)/T-cell lymphoma in Singapore and compared our findings with other series reported in the Asian and Western populations. A panel of immunohistochemical stains, which included CD2, CD3, CD4, CD8, CD56, T-cell intracellular Antigen-1 and granzyme B, and in situ hybridization for Epstein-Barr virus encoded RNA (EBER) were performed. Polymerase chain reaction for T-cell receptor-gamma gene rearrangement using both gel and capillary electrophoresis were evaluated to determine the proportion of tumors which are of true T-cell lineage. We also studied the functional status of the overexpressed p53 protein in these lymphomas by correlating p53 expression with its downstream target protein, p21. In all, 31 out of 42 cases presented in the upper aerodigestive tract. The other sites of involvement included gastrointestinal tract, skin, soft tissue, testis, liver, spleen, bone marrow and brain. The tumors displayed characteristic morphologic features. In situ hybridization for EBER was detected in 41 out of 42 cases (97.6%). The only significant adverse prognostic factor identified was an International Prognostic Index of two or more. A significantly higher proportion of the tumors (27%), compared to previous studies, demonstrated monoclonal T-cell receptor-gamma gene rearrangement. There was, however, no difference in survival or clinicopathologic features between the true NK-cell tumors and their T-cell counterparts. Overexpression of p53 was present in 40% of the cases, but no significant difference in survival rate was detected in patients with p53 overexpression and there was no association between p53 overexpression with large cell morphology, and advanced stage of disease. These findings suggest that molecular aberrations other than those of the p53 pathway may be operative in the pathogenesis of this malignancy.

Comparative analysis of NK/T-cell lymphoma and peripheral T-cell lymphoma in Korea: Clinicopathological correlations and analysis of EBV strain type and 30-bp deletion variant LMP1

Natural killer/T-cell lymphoma (NKTL) and peripheral T-cell lymphomas (PTCL) are prevalent in the Asian population and exhibit a high association with the Epstein-Barr virus (EBV). Moreover, differentiation of these two groups is often difficult and problematic. We investigated 35 cases of NKTL (22 nasal cases and 13 extranasal cases) and 30 cases of PTCL in terms of their clinical features, immunohistology, EBV positivity, EBV strain-type polymorphism and latent membrane protein 1 (LMP1) deletion variant distribution. Eighteen cases (82%) of nasal NKTL and seven (54%) of extranasal NKTL showed EBV positivity by EBV in situ hybridization. Fifteen cases (50%) of PTCL revealed EBV positivity. EBV strain type A was predominant in NKTL (18:5), and EBV strain types A and B were distributed evenly in PTCL (6:6). EBV-positive patients had significantly shorter survival than EBV-negative patients (P < 0.05), and EBV positivity correlated with advanced clinical stage (P < 0.05). Patients harboring type A EBV showed slightly poorer prognoses than those having type B, though it was not obviously statistically different (P = 0.07). The LMP1 deletion variant was prevalent in both NKTL (three wild-type LMP1, 15 deletion variants) and PTCL (three wild-type LMP1, eight deletion variants, two coexistent forms) patients, but did not have prognostic impact. Our results indicate that EBV acts as a negative prognostic factor in NKTL and PTCL, and that the intrinsic properties of a specific viral strain might influence the clinical behavior of these diseases.

Two Entities of Precursor T-Cell Lymphoblastic Leukemia/Lymphoma Based on Radiologic and Immunophenotypic Findings

Precursor T-cell lymphoblastic leukemia/lymphoma (T-ALL/LBL) presents a mediastinal mass in one half of cases. Although the immunophenotypic features of T-ALL/LBL have been analyzed in several studies, few studies have been focused on the relationship between the anatomic distribution of lesions and immunophenotypic findings. We analyzed the clinicopathologic findings for 17 patients with T-ALL/LBL diagnosed since 1993 and whose radiologic findings were available. Data on 14 men and 3 women with a median age of 26 years (range, 10-61 years) were analyzed. On the basis of radiologic findings, the cases were divided into thymic type (n = 8) and nonthymic type (n = 9). Patients with the thymic type of T-ALL/LBL had a large mediastinal mass and minimal systemic lymphadenopathy only in the supradiaphragmatic region. Those with the non-thymic type had predominantly systemic lymphadenopathy that included infradiaphragmatic lesions. Expression of CD8 (6/7 versus 0/9) was more frequently found in the thymic type (P < .001), whereas expression of CD56 (0/7 versus 5/9) was more frequent in the nonthymic type (P = .034). In conclusion, T-ALL/LBL was divided into 2 entities, thymic type and nonthymic type, on the basis of radiologic findings and immunophenotypic features. Analysis of the expression of CD8 and CD56 would be useful for biologically classifying T-ALL/LBL into the 2 types. This study was performed in a single institution, was retrospective, and had a limited number of patients; multicenter confirmatory studies are warranted.

CD56+ hematological neoplasms presenting in the skin: a retrospective analysis of 23 new cases and 130 cases from the literature

BACKGROUND

The aim of this study was to define prognostic parameters and guidelines for diagnosis and treatment for CD56+ hematological neoplasms with first presentation in the skin.

PATIENTS AND METHODS

The study group included 153 cases (23 new and 130 from the literature). According to the World Health Organization classification, the group included 15 nasal and 38 nasal-type natural killer (NK)/T-cell lymphomas, 63 blastic NK-cell lymphomas, 14 cutaneous CD30+ lymphoproliferations, 10 cases of myeloid leukemia, six cases of subcutaneous panniculitis-like T-cell lymphoma (SCPLTCL) and seven peripheral T-cell lymphomas, unspecified.

RESULTS

In general, these CD56+ hematological neoplasms had a poor prognosis, with only 27% of patients alive after a median follow-up of 12 months. The median survival was 13 months. Nasal and nasal-type NK/T-cell lymphomas and CD56+ SCPLTCL had the worst prognosis, with a median survival of 5, 6 and 5 months, respectively. Only nasal-type NK/T-cell lymphomas presenting with only skin lesions had a somewhat better prognosis (median survival 27 months). In blastic NK-cell lymphomas (median survival 14 months), age </=40 years, aggressive treatment with acute leukemia protocols and high TdT expression were associated with a more favorable prognosis. Striking similarities in histology, immunophenotype, clinical presentation and clinical behavior were found between blastic NK-cell lymphomas and CD56+ myeloid leukemias.

CONCLUSIONS

CD56+ hematological neoplasms presenting in the skin have a poor prognosis, except for primary cutaneous CD30+ lymphoproliferations. The striking similarities between blastic NK-cell lymphomas and CD56+ myeloid leukemias presenting in the skin provide a rationale to treat these patients with more aggressive regimens, rather than with CHOP(-like) regimens and radiotherapy, which have proven to be inadequate therapies for this neoplasm.

Subcutaneous, Blastic Natural Killer (NK), NK/T-cell, and Other Cytotoxic Lymphomas of the Skin: A Morphologic, Immunophenotypic, and Molecular Study of 50 Patients

A new group of subcutaneous, natural killer (NK), NK/T-cell, and other cytotoxic T-cell lymphomas of the skin has been recently described, and some have been included as distinct clinicopathologic entities in the classification of hematologic malignancies recently proposed by the World Health Organization. In the European Organization for Research and Treatment of Cancer classification for cutaneous lymphomas, they would be classified either as CD30- large T-cell lymphoma, small/medium pleomorphic T-cell lymphoma, or subcutaneous T-cell lymphoma. Precise clinicopathologic and prognostic features of all of them have not yet been well characterized. We studied retrospectively 81 biopsies from 50 patients with subcutaneous, blastic natural killer (NK), NK/T-cell, or other non-mycosis fungoides cytotoxic T-cell lymphomas of the skin. Clinical, morphologic, phenotypical, and genetic features and data on Epstein-Barr virus association allowed us to classify our cases according to the following 7 categories: a) subcutaneous "panniculitis-like" T-cell lymphoma (SPTCL): 10 cases (estimated 5-year survival: 80%); b) blastic NK-cell lymphoma: 12 cases (estimated 5-year survival: 0%); c) nasal-type extranodal NK/T-cell lymphoma: 5 patients (estimated 5-year survival: 0%); d) epidermotropic CD8+ T-cell lymphoma: 5 cases (estimated 5-year survival: 0%); e) cutaneous gamma/delta T-cell lymphoma: 8 cases (estimated 5-year survival: 0%); f) cutaneous alpha/beta pleomorphic T-cell lymphoma: 8 cases (estimated 5-year survival: 0%); and g) cutaneous medium/large pleomorphic T-cell lymphoma, not otherwise specified: 2 cases. Our study shows that these cutaneous lymphomas can be classified according to precise diagnostic categories. With the exception of SPTCL, analysis of follow-up data from our patients showed that these groups of lymphomas are characterized by an aggressive course, regardless of the diagnostic category.

Histopathology and genetics of cutaneous T-cell lymphoma

There is emerging evidence that genomic and chromosomal instability are features of CTCL, including variants such as MF, Sézary syndrome, and primary cutaneous CD30+ LCAL, and that specific chromosomal abnormalities are common. Additional resolution of specific regions of chromosomal loss and gain are required to define putative genes that may be of fundamental pathogenetic importance in CTCL. Inactivation of well-defined cell cycle and TSG are common as for other types of NHL. The prognostic significance of these abnormalities in CTCL has yet to be determined. The dysregulation of specific transcription factors is of interest, but requires further study. It is hoped that greater understanding of these molecular abnormalities will permit the development of CTCL-specific therapies that alleviate suffering and prolong survival.

Non-B, Non-T Neoplasms With Lymphoblast Morphology

We studied the morphologic, immunohistochemical, and clinical characteristics of 158 cases of lymphoblastic lymphoma. Based on immunophenotyping and cell lineage, cases were classified into B-cell type (CD20,CD19 or CD79a+, n = 53), T-cell type (surface CD3+, n = 84), and non-B, non-T type (B cell marker- and surface CD3-, n = 21). The latter group was further divided based on immunohistochemistry into: 1) CD7+ stem cell lymphoma (CD7+SCL) [CD4-, CD7+, CD33+/-, CD56-], 2) blastic natural killer cell lymphoma (B-NKL) [CD4-, CD7+/-, CD33-, CD56+, CD123-], 3) myeloid/NK precursor cell leukemia (M/NKL) [CD4-, CD7+, CD33+, CD56+], and 4) CD4+CD56+ hematodermic malignancy (CD4+CD56+) type [CD4+, CD7+/-, CD33-, CD56+, CD123+]. The CD7+SCL and M/NKL types frequently exhibited bone marrow invasion and mediastinal masses. All CD4+CD56+ types were associated with skin lesions. B-NKL type is included into Blastic NK lymphoma in new World Health Organization classification with CD4+CD56+ type. But the cases of B-NKL were more reminiscent of CD7+SCL or M/NKL type than the CD4+CD56+ type, both clinically and histologically. We propose that blastic NK lymphoma, a disease entity in the new WHO classification, should be divided into two types based on phenotypes and clinical features. The non-B, non-T lymphomas exhibited poorer prognoses, similar to that of B-cell lymphomas, than T-cell type tumors (P = 0.009). Among the 21 tumors, the prognosis of the four subtypes did not differ significantly; however, cases receiving aggressive chemotherapy and stem cell transplantation had a more favorable prognosis than those receiving only traditional chemotherapy and radiation therapy (P = 0.0089).

Complete remission in advanced blastic NK-cell lymphoma/leukemia in elderly patients using the hyper-CVAD regimen

Although its cell of origin is still controversial, the blastic NK-cell leukemia/lymphoma clearly represents a distinct type of hematopoietic neoplasm that is particularly clinically aggressive when it occurs in elderly patients as a disseminated, multi-organ disease. Consistently effective treatments have not been developed for this malignancy. The present report describes two elderly patients with widespread blastic NK-cell leukemia/lymphoma involving the skin, bone marrow, peripheral blood, lymph nodes, and viscera. In both cases the malignant cells were CD56+, CD2+, and terminal deoxynucleotidyl transferase (TdT) positive with no detectable T-cell receptor (TCR) gamma chain gene rearrangement. The cells also exhibited a low CD45 expression and strong CD99 (mic-2) expression, as seen in immature lymphoid malignancies. The above findings support the precursor NK-cell, rather than mature NK- or non-NK-cell, origin of the malignant cells. It is noteworthy that the two patients achieved complete responses to treatment with hyper-CVAD (fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) alternating with high-dose methotrexate/cytarabine, a regimen currently utilized in acute lymphoblastic leukemia and high-grade lymphoma. The complete remission (CR) was sustained for 24 months in one patient who received four cycles (eight courses) of the treatment. It lasted 9 months in the second patient, who received only two cycles (four courses). If similar results are obtained with future patients, a randomized study comparing the hyper-CVAD regimen to other therapeutic strategies may be warranted.

Variable manifestation in natural killer cell leukaemia

Natural killer (NK) cell leukaemias are a relatively rare group of haematological disorders, now entitled in the T/NK lymphoproliferative disorders in the new WHO classification. Recent studies have clarified their biological and clinical manifestation gradually. However, some cases with NK malignancies still remain difficult to diagnose and differentiate into their subtypes in the absence of a distinct diagnostic hallmark, especially at initial presentation. We describe herein five patients with NK leukaemias with respect to the clinical, cytological, immunological and cytogenetic characteristics, varied among each case. Cytologically, two aggressive NK cell leukaemia/lymphoma (ANKL/L) cases were a morphologically hypogranular variant form. Clinically, one with ANKL/L was presented as haemophagocytic syndrome without leukaemic infiltration. Systemic chemotherapy resulted in complete remission in one ANKL/L and two blastic NK cell leukaemia/lymphoma (BNKL/L) patients; however, a good long-term outcome was achieved in only one CD4-positive BNKL/L patient with allogenic bone marrow transplantation. Cytogenetic analysis revealed that recurrent chromosomal aberration was rare; however, two had aberrations at 10p11 and 11q13. From these findings, we conclude that comprehensive individual studies should be carried out in these patients to obtain a correct diagnosis and to design an optimal therapeutic approach.

Natural killer cell neoplasms: a distinctive group of highly aggressive lymphomas/leukemias

Natural killer (NK) cell neoplasms, which include extranodal NK/T-cell lymphoma (nasal and extranasal) and aggressive NK cell leukemia, are generally rare, but they are more common in people of Oriental, Mexican and South American descent. These neoplasms are highly aggressive, and show a strong association with Epstein-Barr virus. Extranodal NK/T-cell lymphoma most commonly affects the nasal cavity and other mucosal sites of the upper aerodigestive tract. Patients present with nasal obstruction or midfacial destruction. Despite the early stage of disease at presentation, overall survival is poor. Patients with the extranasal form of the lymphoma often present with high-stage disease, commonly involving the skin, gastrointestinal tract, testis, and soft tissue, and the prognosis is even worse. Histologically, the lymphoma can show a broad cytologic spectrum, but apoptosis, necrosis, and angioinvasion are common. The most common immunophenotype is CD2(+), surface CD3(-), cytoplasmic CD3(+), CD56(+). Based on currently available data, treatment of nasal NK/T-cell lymphoma should consist of radiotherapy, with or without multiagent chemotherapy. More research is required to ascertain the role of high-dose chemotherapy with stem cell rescue and that of non-multidrug resistance-related chemotherapeutic agents. Aggressive NK cell leukemia affects younger patients, who present with poor general condition, fever, and disseminated disease; they often die within a short time from systemic disease or complications such as multi-organ failure. The peripheral blood and bone marrow show atypical large granular lymphocytes, which exhibit an immunophenotype similar to that of extranodal NK/T-cell lymphoma. Aggressive NK cell leukemia must be distinguished from T-cell large granular lymphocyte leukemia and indolent NK cell lymphoproliferative disorder, both of which are indolent.

Blastic natural killer cell and extranodal natural killer cell-like T-cell lymphoma presenting in the skin: report of six cases from the UK

BACKGROUND

Some lymphomas express natural killer (NK)-cell markers such as the neural cell adhesion molecule, which is recognized by the CD56 antibody. These lymphomas may present in the skin, but do not represent a homogeneous group. The new World Health Organization classification of lymphoma/leukaemia recognizes several types of NK/T-cell neoplasm, including blastic NK-cell lymphoma, which characteristically presents with cutaneous lesions.

OBJECTIVES

To describe the clinical, pathological and molecular features in six cases of CD56+ lymphoma with cutaneous presentation.

METHODS

The clinical, histopathological and immunophenotypic features of six patients were reviewed. In addition, in situ hybridization (ISH) to identify Epstein-Barr virus (EBV) mRNA, and polymerase chain reaction analysis to identify the presence of a clonal population of T cells or B cells were performed on lesional skin.

RESULTS

All patients presented with widespread nodules and plaques, which in five cases were a characteristic purple colour. Four patients developed disseminated disease, three with neurological involvement. These four patients died between 14 and 46 months following diagnosis (median 30 months). In four of six cases the histopathological and immunohistological features were in keeping with a blastic NK-cell lymphoma. No clonal immunoglobulin heavy chain (IgH) or T-cell receptor (TCR) gene rearrangement was detected in the four cases consistent with an origin from NK cells. A further case fitted the criteria for an extranodal NK/T-cell lymphoma of nasal type and was also the only case to show evidence of EBV mRNA by ISH. A clonal T-cell population was identified in the final case. This patient also exhibited molecular evidence of a clonal B-cell population and a t(14;18) translocation confirmed by sequence analysis.

CONCLUSIONS

Our data confirm that NK-cell lymphomas presenting in the skin are a heterogeneous group, and that in the U.K., blastic NK-cell lymphoma is more common than extranodal NK/T-cell lymphoma of nasal type. These lymphomas pursue an aggressive course, with rapid development of disseminated disease, and resistance to chemotherapy. Detailed immunophenotyping is needed to distinguish the different types. Our molecular data indicate that blastic NK-cell lymphoma cases lack clonal TCR/IgH gene rearrangements consistent with an NK-cell origin. Our ISH findings indicate that EBV plays a pathogenetic role only in extranodal NK/T-cell lymphoma of nasal type.