[Survivin expression in midline T-cell lymphoma in relation to Epstin-Barr virus infection].

To investigate the expression of survivin gene and its relationship with Epstin-Barr virus (EBV) infection in midline T-cell lymphoma (MTL), immunohistochemistry staining method was used to examine the expression of survivin and EBV-latent membrane protein (LMP-1) in the 41 cases. In situ hybridization (ISH) was used to detect EBV-encoded RNA (EBER1/2). The results showed that the expression of survivin was positive in 26 cases of midline T-cell lymphoma, but no positive was detected in 10 cases of reactive lymphoid tissues. The positive expression ratio of survivin was 12.5% in cases of MTL with low grade of malignancy, and was 75.76% in cases of MTL with middle and high grades of malignancy, the significant difference was found between these two groups (chi(2) = 8.55, P < 0.01). Positive expression ratios of EBER1/2 and LMP-1 were 70.73% and 41.46% respectively. Survivin expression was not significantly different between EBER1/2 positive and negative cases (P > 0.05). It is concluded that survivin expression is up-regulated in MTL, and survivin positive expression rate is associated with the degree of malignancy. Survivin may play a role in the pathogenesis of the MTL by influencing cell apoptosis. EBV infection is not significantly associated with survivin expression in the MTL.

P53, N- and K-Ras, and beta-catenin gene mutations and prognostic factors in nasal NK/T-cell lymphoma from Hokkaido, Japan.

We have shown previously that nasal natural killer (NK)/T-cell lymphoma was associated with Epstein-Barr virus (EBV) and had peculiar clinical features. However, little is known about its biological and genetic changes. The aim of this study is to determine the p53, N- and K-ras, and beta-catenin status in this lymphoma in relation to EBV status and clinical features. The study group consisted of 32 Japanese patients with nasal NK/T-cell lymphoma. The p53 and beta-catenin expression, phenotype, and EBV-oncogenic protein latent membrane protein type 1 (LMP-1) were determined by immunoperoxidase staining. The presence of EBV-encoded small nuclear early region (EBER) RNA was determined by in situ hybridization. The p53 mutations (exons 5 to 9), N- and K-ras mutations (exons 1 and 2), and beta-catenin mutations (exon 3) were analyzed by direct sequencing of the PCR-amplified products that were obtained from laser-microdissected tissues. CD56, CD43, and CD3 were expressed in 32 (100%), in 31 (96%), and in 18 (56%) tumors, respectively. EBER RNA was detected in 31 (96%) tumors. LMP-1 was expressed in 15 (48%) tumors, and p53 and beta-catenin protein were overexpressed in 18 (56%) and 4 (13%) tumors, respectively. Six mutations of the p53 gene, 1 mutation of each N- and K-ras gene, and 8 mutations of beta-catenin gene were detected in 6 (19%), 1 (3%), and 5 (16%) tumors, respectively. The p53 missense mutation was associated with LMP-1 expression (P = 0.038), but not with p53 overexpression. Kaplan-Meier analysis as well as univariate analysis using Cox proportional hazards model showed that high lactate dehydrogenase (LDH) level (P = 0.009, P = 0.0100, respectively), large cell, immunoblastoid polymorphous histology (P = 0.005, P = 0.0162, respectively), and p53 missense mutations (P = 0.021, P = 0.0342, respectively) were significantly related to worse cause-specific survival. Multivariate analysis showed that p53 missense mutation was the most independent among these 3 factors. Although the incidence of thep53, N- and K-ras, and beta-catenin gene mutations is not high, p53 missense mutation has a prognostic value for aggressive course in nasal NK/T-cell lymphoma.

[Reactive hemaphagocytic syndrome in a patient with midline NK-cell lymphoma]. / Syndrome d'activation macrophagique au cours d'un lymphome NK centro-facial.

Different etiologies have been shown to underly lethal midline granuloma. Evidence of natural killer cell lymphoma is obtained by immunolabeling and molecular biology studies. The tumor has a characteristic immunophenotype and genotype. This clinicopathological entity is highly associated with Epstein-Barr virus (EBV). We present the case of a patient with EBV associated with nasal-type natural-killer cell lymphoma and a coexisting hemophagocytic syndrome.

Characterization of a novel human natural killer-cell line (NK-YS) established from natural killer cell lymphoma/leukemia associated with Epstein-Barr virus infection.

A novel cell line was established from a patient with a leukemic-state nasal angiocentric natural killer (NK) cell lymphoma with systemic skin infiltration. The morphology of the leukemic cells was large-granular-lymphocyte (LGL), and their immunophenotype was CD2+, CD3-, CD5+, CD7+, CD16-, CD56+, and CD57-. The presence of Epstein-Barr viral (EBV) genome was shown in specimens from the patient's nose, skin, and peripheral blood by in situ hybridization using an EBV-encoded small RNA-1 probe or by Southern blotting using a terminal-repeat probe of the EBV genome. Leukemic cells were cocultured with a mouse stromal cell line (SPY3-2) in the presence of 100 U/mL recombinant human interleukin-2 and a novel stromal cell-independent cell line, NK-YS, was established. The NK-YS cells showed LGL morphology and expressed surface CD2, CD5, CD7, CD25, CD56, and CD95. The NK-YS cells retained cytotoxicity against K562 and Jurkat cells. A Southern blotting using a terminal-repeat probe of EBV showed that NK-YS and fresh leukemic cells had a clonal EBV genome, whereas the T-cell receptor beta and gamma chain genes of NK-YS were not rearranged. In an immunocytochemical analysis, the NK-YS cells showed a type-II latent infection of EBV. The NK-YS cells preserved the original characteristics of NK cell lymphoma/leukemia and will be a useful tool for the study of biological characteristics of EBV-associated nasal angiocentric NK cell lymphoma/leukemia.

Sinonasal T-cell lymphoma in the differential diagnosis of lethal midline granuloma using in situ hybridization for Epstein-Barr virus RNA.

"Lethal midline granuloma" of the upper airways generally encompasses T-cell lymphoma and Wegener's granulomatosis in Western populations. Treatment and outcome for each is different, but their pathological distinction may not always be possible on routine biopsy specimens. Within a defined population between 1947 and 1994, we found 12 cases of primary sinonasal T-cell lymphoma, all with a CD20-, CD3+ immunophenotype in paraffin sections. We studied the occurrence of the Epstein-Barr virus RNA EBER1 using colorimetric in situ hybridization (ISH) with an oligoprobe. All available biopsy specimens from each patient were hybridized to detect the presence of EBER1 in relation to the phase of lymphoma progression. In addition, ISH was performed on 23 cases of nonspecific rhinitis and 10 cases of Wegener's granulomatosis to determine the specificity of the method in the differential diagnosis of inflammatory/ulcerative lesions. In ten cases of lymphoma, initial biopsy specimens showed the early phase with minimal lymphocytic atypia ("polymorphic reticulosis"). Four of these (including one recurrence) had been missed by experienced pathologists, resulting in a diagnostic delay of 2 to 8 yr. The remaining two cases were in the late phase, i.e., malignant grade atypia was apparent in the initial biopsy specimen, and neither was misdiagnosed as being benign. All hybridizable lymphoma sections, regardless of phase of development, gave a strong ISH signal easily detected at low magnification in 50 to 100% of tumor cells. Scattered positive cells were usually present even in necrotic areas. In contrast, no case of Wegener's granulomatosis or nonspecific rhinitis produced a true hybridization signal. We conclude that a negative EBER1 ISH provides strong evidence against T-cell lymphoma in the differential diagnosis of lethal midline granuloma in our population. Conversely, a strong ISH signal for EBER1 in immunohistochemically determined T-cell infiltrates within sinonasal tissues provides strong support for the presence of lymphoma.

[Two cases of lethal midline granuloma thought to be of natural killer cell origin].

So called lethal midline granuloma is of great clinical and theoretical interest. Recent evidence has shown that most lethal midline granulomas are associated with a T-cell phenotype and they are therefore referred to as nasal T-cell lymphomas (NTCL). Immunohistochemical studies, however, have shown peculiar phenotypic features such as expression of natural killer (NK)-cell-related markers and extensive T-cell antigen loss including absence of expression of alpha beta T-cell receptor (TCR). In this study, we reported genotypic and immunohistochemical features in two cases of lethal midline granuloma. The histopathological diagnosis of the biopsy specimens was polymorphic reticulosis/midline malignant reticulosis. Both cases displayed a CD2+, CD3-, CD3 epsilon+, CD4-, CD8-, CD16-, CD56+ phenotype, suggesting that these tumors may be peripheral T-cell lymphomas with extensive loss of T-cell antigens and expression of NK cell antigen (CD56), or, alternatively, NK cell neoplasias. No TCR beta gene rearrangement was detected in these cases. Monoclonal Epstein-Barr virus (EBV) genome was detected in each specimen by Southern blot hybridization. The tumor cells in one of the two cases expressed latent membrane protein (LMP). These findings support the concept that lethal midline granuloma constitutes a distinct group of lymphomas that, in addition to their peculiar clinical features, exhibits the phenotype of extensive loss of T-cell antigens and expression of the NK cell antigen, as well as harbors the EBV. In view of the LMP-transforming potential, these data suggest that EBV may play a role in the pathogenesis of lethal midline granuloma.

Polymorphic reticulosis is a neoplasm of large granular lymphocytes with CD3+ phenotype.

BACKGROUND: Polymorphic reticulosis, a type of lethal midline granuloma (LMG), has been referred to as nasal T-cell lymphoma (NTL) because of its proliferating cells' positive reactivity to anti-T-lymphocyte antibodies. Recently, several studies have suggested that proliferating cells in NTL may be natural killer (NK) in nature. NK cells and human nonmajor histocompatibility-restricted cytotoxic T-lymphocytes have the morphology of large granular lymphocytes (LGL) (i.e., a high cytoplasmic:nuclear ratio and cytoplasmic granules). Whether NTL-LMG possesses an LGL morphology is examined in this study. METHODS: Two lymph node smears, peripheral blood showing a leukemic picture, and an electron microscope (EM) examination of a cutaneous lesion, respectively, were obtained from four patients with NTL-LMG. Immunohistochemical examination of the proliferating cells and of the Epstein-Barr virus (EBV) genome by both polymerase chain reaction and in situ hybridization also were performed. RESULTS: All patients presented with necrotic and granulomatous lesions in the upper respiratory tract. Histology showed polymorphous cellular infiltrates containing large atypical cells with positive reaction to CD3 (three patients), CD43 (two patients), CD45RO (two patients), and OPD4 (one patient). Imprint smears revealed azurophilic large membrane-delimited granules in an ample cytoplasm, which was confirmed by EM. The presence of the EBV genome in the tumor cells was observed in one patient. CONCLUSION: The current findings showed that NTL-LMG or polymorphic reticulosis is a proliferation of LGL with a CD3+ phenotype.