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

Frequent concomitant epigenetic silencing of the stress-responsive tumor suppressor gene CADM1, and its interacting partner DAL-1 in nasal NK/T-cell lymphoma

Nasal NK/T-cell lymphoma (NL) is a rare but clinically important entity of lymphoma. Its preferential incidence in Orientals but not Caucasians suggests possible genetic predisposition. 11q deletion is common in NL, indicating certain tumor suppressor genes (TSGs) at this locus involved in its pathogenesis. We investigated the expression and methylation of an 11q23.2 TSG, CADM1 (or TSLC1), and its partner DAL-1 (or EPB41L3) in NL. Methylation and silencing of CADM1 were detected in 2 NL and 4 of 8 (50%) of non-Hodgkin lymphoma (NHL) cell lines, but not in normal NK cells and normal PBMC. Absence of CADM1 protein was also detected in NL cell lines. 5-aza-2'-deoxycytidine (Aza) demethylation or genetic knockout of both DNMT1 and 3B genes restored CADM1 and DAL-1 expression. CADM1 methylation was further detected in 36 of 45 (80%) of NL tumors. Concomitantly, DAL-1 was epigenetically inactivated in NL cell lines and virtually all the tumors with methylated CADM1. A significant correlation between the methylation of both genes was found (p < 0.0001). Homozygous deletion of CADM1 was detected in only 3 of 18 (17%) of tumors. The stress-response of CADM1 was abolished when its promoter becomes methylated. Our results demonstrate a frequent, predominant epigenetic silencing of CADM1 and DAL-1 in NL, which likely play a synergic role in NL pathogenesis.

Nasal NK/T-cell lymphoma: epidemiology and pathogenesis

Nasal NK/T-cell lymphoma (NKTCL) is an uncommon disease, but usually shows a highly aggressive clinical course. The disease is much more frequent in Asian and Latin American countries than in Western countries, and is universally associated with Epstein–Barr virus (EBV) infection. Analyses of gene mutations, especially p53 and c-KIT, revealed the different frequencies by district. Epidemiological studies revealed the changes of the disease frequency in Korea during the period from 1977–1989 to 1990–1996. Case-control study showed that the exposure to pesticides and chemical solvents could be causative of NKTCL. Further studies including HLA antigen typing of patients is necessary to further clarify the disease mechanism.

Granulomatous Diseases and Chronic Rhinosinusitis

Chronic rhinosinusitis often fails to respond to standard medical or surgical treatment. In some of these cases, the underlying disease may be a chronic granulomatous process that requires aggressive topical, local, and in some instances, systemic therapy. Diseases that can present in this manner include autoimmune vasculitis, sarcoidosis, indolent infections, neoplastic processes, and various other miscellaneous conditions. This article reviews the typical presentations for some of these unusual conditions and discusses the appropriate evaluations that will lead to clinical identification and effective medical management.

Sinonasal lymphoma: a clinicopathologic analysis of 58 cases from the Massachusetts General Hospital

Few large series compare lymphomas of the nasal cavity with those of the paranasal sinuses. We studied the cases of 58 patients, 34 males and 24 females, aged 7 to 92 years (mean, 57 years), who had lymphoma involving the nasal cavity or paranasal sinuses. Thirty-three patients had diffuse large B-cell lymphoma (DLBCL). Twenty-three were male and 10 were female, with an age range of 7 to 91 years (mean, 63 years); two were HIV-positive. Only 2 of 11 cases tested (one in an HIV-positive patient and one of lymphomatoid granulomatosis type) were Epstein-Barr virus (EBV)-positive. Thirty (91%) involved paranasal sinuses, 10 with nasal involvement, whereas three cases had nasal, but not sinus, involvement. At last follow-up, 16 (67%) were free of disease 7 to 169 months later (mean, 65 months), and 8 (33%) had died of disease 2 to 166 months later (mean, 45 months). Seventeen patients had nasal-type natural killer (NK)/T-cell lymphoma. There were 10 women and 7 men, aged 27 to 78 years (mean, 48 years). Thirteen of 14 were EBV-positive. Sixteen patients had nasal involvement, eight with sinus involvement. Eleven (73%) of 15 were alive and well 6 to 321 months later (mean, 139 months), three (20%) died of lymphoma 1, 11, and 12 months later, and one (7%) is alive with disease. There was one case each of marginal zone B-cell lymphoma, Burkitt's lymphoma, Burkitt-like lymphoma, peripheral T-cell lymphoma of unspecified type, and adult T-cell lymphoma/leukemia. In an additional three cases, the lymphomas were composed predominantly of large cells, but no immunophenotyping could be performed for subclassification. In 19 cases (17 DLBCLs, 1 Burkitt-like lymphoma, and 1 lymphoma of uncertain lineage), presenting symptoms included complaints related to the eyes. In 16 cases (13 DLBCLs, 1 Burkitt-like lymphoma, 1 nasal NK/T-cell lymphoma, and 1 lymphoma of uncertain lineage), the orbit was invaded by lymphoma. In our series, the most common lymphoma to arise in the sinonasal area is DLBCL, followed by nasal NK/T-cell lymphoma. Comparison of these two types of lymphoma showed that lymphomas involving sinuses without nasal involvement were predominantly DLBCLs (20 of 21), whereas nasal cavity lymphomas without sinus involvement were usually NK/T-cell type (8 of 11) (p = 0.000125). Compared with patients with DLBCL, patients with nasal NK/T-cell lymphoma were overall younger, with a lower male-to-female ratio. Lymphomas of B-cell lineage were more likely to be associated with symptoms related to the eyes (p < 0.0005) and to have extension to the orbit (p < 0.01) than were lymphomas of T- or NK-cell lineage. In contrast to results of Asian studies in which nasal NK/T-cell lymphoma has a very poor prognosis, our nasal NK/T-cell lymphomas had an outcome similar to that of DLBCL.

Immunophenotypic and genotypic characterization of nasal lymphoma with polymorphic reticulosis morphology

Nasal lymphoma with polymorphic reticulosis (PR) morphology is now categorized as T/natural killer (T/NK) cell lymphoma. In this study, immunophenotypes and genotypes of proliferating cells in 21 cases with PR were examined. The patients included 13 men and 8 women ranging in age from 20 to 74 (median 37) years. All patients presented with lesions in the upper respiratory tract, mostly in the nasal cavity. Histological specimens obtained from the primary lesions (19 cases) and metastatic cervical lymph nodes (2 cases) were used for analyses. Histologically, polymorphous proliferation was found in 20 cases, and these were thus diagnosed as PR. A monomorphous pattern was found in the remaining last case. Immunohistochemical analysis revealed that the proliferating cells were CD56 (123C3)+ and/or CD16 (2H7)+, TIA-1+ and frequently stained CD3 epsilon+. Tumor cells were frequently stained positively with monoclonal antibodies (mAbs) for T lymphocytes, but were negative for T-cell receptor (TCR) beta and delta chain expression. In situ hybridization analysis using an Epstein-Barr virus-encoded early RNA 1 (EBER-1) probe revealed positive signals in 13 of the 15 cases examined. Southern blotting analysis for clonality of the Epstein-Barr virus (EBV) genome in 12 positive cases confirmed the presence of monoclonal proliferation in 7 cases. The pattern of TCR gamma chain gene rearrangement was examined by PCR analysis of DNA from tumor tissues by the denaturing gradient gel electrophoresis method. The results demonstrated no clonal rearrangement in any of the 21 cases examined, including 7 cases with proven clonal proliferation of EBV-infected cells, indicating the absence of T-cell clones. Our findings strongly suggested that nasal T-cell lymphoma is in fact a NK cell lymphoma.

Natural killer cell-derived large granular lymphocyte lymphoma of lung developed in a patient with hypersensitivity to mosquito bites and reactivated Epstein-Barr virus infection

A 17-year-old female developed natural killer (NK) cell-derived large granular lymphocyte (LGL) lymphoma of the lung. She had a past history of hypersensitivity to mosquito bites (HMB). After an eight-year chronic, active Epstein-Barr virus (EBV) infection, she developed multiple lung lesions and pleural effusion. In the effusion, 60% of the cells were LGL. They were CD2+, 3-, 16+, 56+, 57+, 45RO+/RA + weak, and possessed strong NK activity. No rearrangement of T-cell-receptor genes was detected. From all these results, a diagnosis of NK-LGL lymphoma of the lung was made. EB virus DNA was detected in cells infiltrating the pleural effusion. The clonality of the LGLs was determined by Southern blot hybridization with the terminal repeat sequence of EB virus as a probe, and by chromosomal abnormalities. The patient died from respiratory failure. Necropsy of the lung revealed diffuse lymphoma composed of polymorphic cells with typical angiocentric lesions. Reportedly, lymphomas of NK lineage show predominantly extranodal involvement, and primary lung lesions are rare. In the pleural effusion of the present case, abnormally high levels of soluble Fas ligand, interleukin-10 and interferon gamma were detected. This hypercytokinemia, reflecting the microenvironment of lymphoma cells, may play a role in the progression of the lymphoma and organ injury in the lung.

Epstein-Barr virus in lymphoproliferative diseases in the sino-nasal region: close association with CD56+ immunophenotype and polymorphic-reticulosis morphology

Association between Epstein-Barr virus (EBV) and nasal T-cell lymphoma (NTL) has been demonstrated. NTL has 2 types of histologic figures: one is ordinary non-Hodgkin's lymphoma (NHL) with monomorphous proliferation, and the other is polymorphic-reticulosis (PR) morphology. The presence of the EBV genome and its sub-types (A and B) were examined on paraffin-embedded specimens from 36 cases of sino-nasal lymphomas (SNL) collected from Seoul, Republic of Korea, where the frequency of NTL is high. Patients' ages ranged from 2 to 74 years (median 54 years) with a male-to-female ratio of 2.5:1. Immunophenotypically, 8 cases were B-cell type, 11 were T-cell type with CD56-, 14 were CD56+ type, and 3 were null-cell type. Five of 11 cases with ordinary NHL of T-cell type and 9 of 14 cases with PR were CD56+. The EBV genome was found by polymerase chain reaction (PCR) and in the tumor cells by in situ hybridization (ISH) in 1 of 4 B-cell type (25%), 5 of 10 T-cell type (50%), 11 of 13 CD56+ type (85%), and in both of null-cell type (100%). Of 16 cases with PR morphology, 15 (94%) were positive for the EBV genome. All of the 5 NTLs of ordinary NHL with CD56- were negative for EBV. Concerning the sub-type of EBV, 16 cases had type A, while none had type-B EBV. These findings suggest that NTL comprises 2 groups: EBV-positive NTLs are CD56+ and/or histologically PR, and EBV-negative NTLs are CD56- and histologically ordinary NHL. The current results on Korean patients, together with earlier studies on Japanese and Malaysian patients, have shown the predominance of type-A EBV in sino-nasal lymphoma in Asia.

Clinicopathologic study of nasal T/NK-cell lymphoma among the Japanese

A high prevalence of nasal lymphoma expressing a T- or natural killer (NK)-cell phenotype (NTCL) with frequent association of Epstein-Barr virus (EBV) has been indicated in Asians. To characterize NTCL among the Japanese, the clinicopathologic features of 32 cases were evaluated and the cases were also analyzed for EBV-RNA using an ISH method. Morphologically, 31 cases were identified by atypical pleomorphic lymphoid infiltrates with polymorphous, angicentric, and necrotic features. Their lymphoma cells ranged in size from small to large and were mixed in varying proportion from case to case. The other one case showed a monomorphic 'blastic' appearance. EBV-encoded small RNA (EBER) was detected in the neoplastic cells of 27 of the 32 cases examined. In the five EBV-negative cases, one was the 'blastic' type. Clonal T-cell receptor gene rearrangement was detected in none of seven cases examined. The patients had a median follow-up of 9 months (range, 1 month to 14 years and 11 months). The Kaplan-Meier estimate of overall survival was 49% at 5 years, correlating with clinical stage. These data support the concept that most cases of NTCL are identified as tumors with T/NK-cell characteristics and EBV association, distinctly different from other peripheral T-cell lymphomas. Furthermore, the one case of an EBV-negative 'blastic' variant appears not to fit well into the pleomorphic category but more closely resembles the pathologic features of extranasal angiocentric lymphoma with lymphoblastoid appearance. This study also showed no clear difference in clinical aspects other than the original site or in prognosis, between NTCL and extranasal angiocentric lymphomas despite the higher incidence of EBV association and the tendency for that peculiar anatomical site to be restricted to the former group.

Nasal T/NK cell lymphoma: a clinico pathologic study of 30 west Chinese patients with special reference to proliferation and apoptosis

Midfacial T-cell lymphomas are more prevalent in Asia than in Europe or North America. Clinically, these lymphomas are noted as one major differential diagnosis in the malignant midline granuloma syndrome. During the past years, the group of nasal T/NK cell lymphomas has been recognized that is frequently associated with EBV-infection. The aim of the current publication was to describe the clinical presentation and course of 30 patients attending the West China University of Medical Sciences, Chengdu, P.R. China, between 1991 and 1994. Clinical records were assessed and the patients were followed for 6 to 29 (mean 12.4) months. Several microscopic features thought to be associated with this entity were carefully evaluated together with immunohistochemical data. The proliferation of the tumour cells was assessed by determining the mitotic index and the ratio of MIB-1 labelled cells. In addition, the incidence of apoptotic cells was investigated by means of the in-situ end labelling (ISEL) technique. Our data confirm the expression of T-cell markers by T/NK cell lymphomas as determined by the immunohistochemistry. The apoptotic index was found to correlate with the ratio of MIB-1 labelled cells. Expression of the bcl-2 oncoprotein was not associated with increased or diminished proliferation or cell death, respectively. Eight of the thirty patients succumbed to their disease during the follow-up period. Kaplan-Meier cumulative survivals and log-rank tests revealed a significant impact of MIB-1 labelling on mean survival times.

Infectious agents and environmental factors in lymphoid malignancies

A strong association was found to exist between patterns of lymphoid malignancies and socioeconomic status. B-cell lymphomas and T-acute lymphoblastic leukemia are much more prevalent in developing countries where the chances of acquiring infections especially at a younger age are high. B-cell precursor acute lymphatic leukemia, however, are much more prevalent in the Western world. Many infectious agents are associated with lymphatic malignancies. Epstein-Barr virus is involved in African Burkitt's lymphoma, human immunodeficiency virus-related Burkitt's lymphoma, lymphoproliferative syndrome post-transplantation, and Hodgkin's disease. Other infectious agents which may play a role in lymphoproliferative disorders are human immunodeficiency virus in acquired immune deficiency syndrome-associated lymphoma, human T-lymphotropic virus in adult T-cell lymphoma, Helicobacter pylori in mucosa-associated lymphoid tissue lymphoma, theileriosis in lymphoproliferative syndrome in cattle, Avian leukosis virus in chicken bursal lymphoma, and possibly a bacterial infection in immunoproliferative small intestine disease, potentially reversed by antibiotic therapy. The association between infectious agents and hematologic malignancies may be explained by the creation of large populations of activated cells followed by higher occurrences of 'genetic accidents'. This theory may be reinforced in at least some malignancies with the existence of viral proteins which either have complex relationships with key cellular gene products like p53 and Rb which have roles in cell cycle control, or share common motifs with bc1-2, therefore operating as anti-apoptotic elements. Whenever these genes are deranged, cell deoxysibonucleic acid repair or apoptosis are no longer possible, thereby creating a state of genome instability, increased acquisition of mistakes, and increased chances for malignant transformation.

Angiocentric T-Cell Lymphoma of the Tonsil: A Case Report

We present a case of an angiocentric T-cell lymphoma (ACTL) occurring in a 31-year-old woman with the Acquired Immunodeficiency Syndrome (AIDS). This patient had oropharyngeal pain, a non-healing superficially ulcerated right tonsil, and no obvious tumor mass. Initial tonsillar biopsy revealed a subtle, non-specific, perivascular lymphocytic infiltrate subjacent to an ulcerated and inflamed mucosal lining. A benign, although atypical, inflammatory process was suspected. The distinctive features in this case include the relationship of ACTL to the Epstein-Barr Virus (EBV), which is usually related to B-cell lymphoproliferative disorders, the unique non-midline location of the lesion, and the relationship of ACTL to AIDS. ACTL appears to represent a unifying pathologic entity encompassing formerly described angioinvasive lymphoid lesions including polymorphic reticulosis, midline lethal granuloma, and lymphomatoid granulomatosis. We present these subtle histopathologic features to alert otolaryngologists who may encounter these cases, especially in AIDS patients who present extensive diagnostic possibilities. To the best of our knowledge, this is the first case report of ACTL involving the tonsil.

Discordant CD3 expression in lymphomas when studied on frozen and paraffin sections

The results of CD3 staining in the T or putative natural killer (NK) cell lymphomas of nasal and extranasal sites as reported in the literature have been confusing, with some studies reporting a low rate of CD3 positivity and others a high frequency of CD3 staining. The former studies were performed on fresh or frozen tissues, whereas the latter were performed on paraffin sections using a polyclonal antiserum (poly-CD3). Although previous studies have suggested a high concordance rate of CD3 staining between fresh/frozen tissues and paraffin sections, many CD3- cases have not been studied, and the more reliable antigen retrieval techniques have not been applied. In this study, we addressed the question of discordant CD3 expression by comparing the results of CD3 staining in lymphomas as studied on frozen sections and as studied on paraffin sections (with antigen retrieval effected by pressure cooking). This series was biased toward inclusion of a high percentage of cases of putative NK cell lymphomas, which are prevalent among Asians and usually show a CD2+ CD3(Leu4)- CD56+ immunophenotype. Among 35 cases of CD3(Leu4)- T- and T/NK-cell lymphomas, 30 (86%) showed staining with poly-CD3 on paraffin sections. All 15 CD3(Leu4)+ T-cell lymphomas showed positive staining with poly-CD3 on paraffin sections. None of 60 B-cell lymphomas were stained by poly-CD3, confirming no loss of specificity of staining with this antiserum despite use of an effective antigen-retrieval technique. The discordance rate of CD3 staining in T- and T/NK-cell lymphomas in this series was 60%, and this phenomenon was most commonly observed in the CD56+ T/NK-cell lymphomas: CD3(Leu4)- in frozen sections but poly-CD3+ in paraffin sections. Therefore, to avoid confusion, we propose designating the results based on fresh/frozen tissues CD3(f) and those based on poly-CD3 application on paraffin sections CD3(p) in future reporting of CD3 immunophenotype.