Lethal midline granuloma with a novel T-cell phenotype as found in peripheral T-cell lymphoma

Deciphering the role of Epstein-Barr virus in the pathogenesis of T and NK cell lymphoproliferations

Epstein-Barr virus (EBV) is a highly successful herpesvirus, colonizing more than 90% of the adult human population worldwide, although it is also associated with various malignant diseases. Primary infection is usually clinically silent, and subsequent establishment of latency in the memory B lymphocyte compartment allows persistence of the virus in the infected host for life. EBV is so markedly B-lymphotropic when exposed to human lymphocytes in vitro that the association of EBV with rare but distinct types of T and NK cell lymphoproliferations was quite unexpected. Whilst relatively rare, these EBV-associated T and NK lymphoproliferations can be therapeutically challenging and prognosis for the majority of patients is dismal. In this review, we summarize the current knowledge on the role of EBV in the pathogenesis of these tumours, and the implications for treatment.

[Primary nasal natural killer/T-cell lymphomas: classification and clinicopathological features]

BACKGROUND

Nasal NK/T-cell lymphomas are rare malignancies in Europe or North America. Histological diagnosis is difficult, because tumors imbedded in large necrotic areas and neoplastic infiltrates may be admixed with small lymphocytes, plasma cells, eosinophils, and histiocytes, and thus the process could be misdiagnosed as chronic inflammation. Progression of the disease leads to septal perforation and may also result in destruction of the hard palate, and if left untreated it ends fatally. This introduced the term "lethal midline granuloma", a term which should not be used any more.

MATERIAL AND METHODS

Clinical features, pathohistology, and current classification of primary nasal NK/T-cell lymphomas are described against the background of the recent literature and a case report.

RESULTS

Immunophenotyping is essential for the diagnosis. Tumor cells are uniformly infected by Epstein-Barr virus, which could be verified by EBER in situ hybridization. Immunohistochemically, tumor cells are positive for CD56, cytoplasmic CD3epsilon, and CD2 and they express cytotoxic molecules like granzyme B, TIA-1, GMP17, and perforin. Therapeutic options are radio- or radiochemotherapy. On average, 2- and 5-year survival rates of 50% are obtained in stages I and II. The prognosis of advanced tumor stages is very poor.

CONCLUSIONS

Immunohistochemical and molecular genetic early diagnosis is of crucial prognostic relevance.

Clinicopathologic Study of Non-Hodgkin Lymphoma in Sinonasal and Hard Palate Regions in 15 Japanese Cases

Non-Hodgkin lymphomas of the sinonasal region have been the subject of numerous studies. Previous reports have suggested that nasal lymphomas occurring in Orientals are mostly of the natural killer cell (NK)/T-cell phenotype which contrasts with the preponderance of the B-cell type in western populations. Recent studies indicated that NK/T-cell lymphoma constitutes the clinical condition of lethal midline granuloma. These reports led us to question whether all NK/T lymphomas are always lethal midline granuloma. We have investigated a series of 15 cases of non-Hodgkin lymphomas in the nasal and/or paranasal sinuses clinically, immunohistochemically and for the presence of Epstein-Barr virus (EBV). This study showed that the presence of EBV was common in nasal NK/T lymphoma, and this type of lymphoma was clearly highly frequent in other types of nasal lymphoma in our department. Moreover, in 4 cases of NK/T-cell lymphomas, the clinical features of lethal midline granuloma did not appear, indicating that NK/T lymphomas are not always lethal midline granuloma.

Review article: oral ulcers and its relevance to systemic disorders

Oral ulceration is a common problem, and is sometimes a marker of gastroenterological disease. Patients with signs or symptoms of oral ulcers are sometimes referred to gastroenterology clinics, however, in most instances the ulcers does not reflect gastrointestinal disease. Indeed, a spectrum of disorders other than those of the gut can give rise to oral mucosal ulcers ranging from minor local trauma to significant local disease such as malignancy or systemic illness. This present article reviews aspects of the aetiology, diagnosis and management of common ulcerative disorders of the oral mucosa.

Characterization of novel natural killer (NK)-cell and gammadelta T-cell lines established from primary lesions of nasal T/NK-cell lymphomas associated with the Epstein-Barr virus

Studies on nasal T/natural killer (NK)-cell lymphoma have been hampered by its tendency to cause necrosis. Thus, the establishment of cell lines of this neoplasm would seem to be valuable. This study attempted to establish cell lines from primary lesions of this tumor, and successfully obtained 2 novel Epstein-Barr virus (EBV)-positive cell lines, SNK-6 and SNT-8, by means of high-dose recombinant interleukin 2. Flow cytometry showed that SNK-6 had an NK-cell phenotype, CD3- CD4- CD8- CD19- CD56+ T-cell receptor (TCR) alpha/beta- TCR gamma/delta-, whereas SNT-8 was CD3+ CD4- CD8- CD19- CD56+ TCR alpha/beta- TCR gamma/delta+. These were consistent with immunophenotypes of their original tumors, and the cell lines had monoclonal EBV clones identical to ones in their original tumors. Thus, the cell lines developed from cells forming the primary lesions. Genotypic analysis showed that SNK-6 had unrearranged TCR and immunoglobulin heavy-chain genes, supporting the conclusion that SNK-6 was of NK-cell lineage. On the other hand, SNT-8 had rearranged TCR beta-, gamma-, and delta-chain genes, and together with its phenotype, SNT-8 proved to be a gammadelta T-cell line. This is the first report of the establishment of cell lines from primary lesions of nasal T/NK cell lymphomas, and the results demonstrated that there are at least 2 lineages, NK- and gammadelta T-cell, in this neoplasm. Moreover, it has been suggested that nasal T/NK cell lymphomas of these lineages may belong to the same clinicopathologic entity because both types of cases shared common clinical and histopathologic features.

Clinicopathological features of Epstein-Barr virus-associated nasal T/NK cell lymphomas in southern Japan

OBJECTIVE

Nasal T/natural killer cell lymphomas (NTCL) are highly prevalent among Oriental populations. However the characteristic immunophenotype of NTCL is still controversial and it can be difficult to make a firm histologic diagnosis of malignancy. Therefore, 14 cases of NTCL in patients from southern Japan were evaluated for clinicopathological features and immunophenotypic status. Furthermore, the genetic variations in the latent membrane protein 1 (LMP-1) gene of Epstein-Barr virus (EBV)-related NTCL were evaluated.

METHODS

Biopsy specimens were fixed in formalin and embedded in paraffin before examination using in situ hybridization for EBV-encoded RNA-1 (EBER-1) as well as immunohistochemical staining for CD3, CD3epsilon, CD4, CD8, CD43, CD45RA, and CD45RO. To detect genetic variations, single-strand conformation polymorphism (SSCP) analysis and DNA sequencing were applied.

RESULTS

Clinically, 14 cases were divided into two groups. The first group consisting of eight patients showed good prognosis. The other group consisting of six patients showed poor prognosis. The vast majority of neoplastic cells in NTCL were EBER-1 positive. These cells did not express CD4, CD8, or CD45RA, but often expressed CD43 and CD45RO. In addition, they were negative for CD3 when stained with a mouse monoclonal antibody but stained for CD3epsilon when a rabbit polyclonal was used. The 3'-terminal of LMP-1 gene of seven cases were amplified and all of them have 30 base pair (bp) deletion.

CONCLUSION

NTCL are a heterogeneous mix of cell types although EBV-associated NTCL in patients from southern Japan appear to originate from natural killer cells rather than T cells, and also prognosis is variable and not always poor. The ability to make a firm diagnosis can be enhanced through the combined use of in situ hybridization and immunohistochemistry. High prevalence of the 30-bp deletions of the LMP-1 gene in EBV-related NTCL may also reflect the prevalence of the deletion variant in the normal population in Japan.

CD7+ and CD56+ Myeloid/Natural Killer Cell Precursor Acute Leukemia: A Distinct Hematolymphoid Disease Entity

The disease spectrum of natural killer (NK) cell leukemias and lymphomas has recently been expanding with the continuing evolution in diagnostic concepts. We describe here seven cases of acute leukemia of conceivable myeloid and NK cell precursor phenotype in six men and one woman varying from 19 to 59 years of age (median, 46 years). Striking extramedullary involvement was evident at initial presentation, with peripheral lymphadenopathy and/or mediastinal masses. Two lacked any leukemic cells in the bone marrow at diagnosis. Using cytochemical myeloperoxidase staining, less than 3% of the leukemic cells showed positive reactivity. However, expression of CD7, CD33, CD34, CD56, and frequently HLA-DR, but not other NK, T-cell, and B-cell markers was observed. Cytoplasmic CD3 was detected in three of the cases by flow cytometry and in six by Northern blotting, suggesting an origin from common progenitors between the NK cell and myeloid lineages. All but one presented germline configurations of the T-cell receptor β and γ chain genes and Ig heavy chain gene. With regard to morphology, the cells were generally L2-shaped, with variation in cell size, round to moderately irregular nuclei and prominent nucleoli, pale cytoplasm, and a lack of azurophilic granules. Histopathologic examination of biopsied specimens of extramedullary tumors showed a lymphoblast-like morphology, implying the differential diagnostic problem from lymphoblastic lymphomas, especially in cases lacking bone marrow involvement. Three patients were successfully treated with chemotherapy for acute myeloid leukemia (AML), whereas three other patients proved refractory to chemotherapeutic regimens for lymphoid malignancies, although two responded to subsequent AML chemotherapy. However, despite intensive chemotherapy, including allogeneic bone marrow transplantation, most persued fatal courses within 41 months. These data suggested that the CD7+ and CD56+ myeloid/NK cell precursor acute leukemia might constitute a distinct biologic and clinical disease entity. Its recognition appears to be particularly important for the clinicopathologic evaluation of CD56+ hematolymphoid malignancies and the development of therapeutic approaches to such disease.

CD7+ and CD56+ Myeloid/Natural Killer Cell Precursor Acute Leukemia: A Distinct Hematolymphoid Disease Entity

The disease spectrum of natural killer (NK) cell leukemias and lymphomas has recently been expanding with the continuing evolution in diagnostic concepts. We describe here seven cases of acute leukemia of conceivable myeloid and NK cell precursor phenotype in six men and one woman varying from 19 to 59 years of age (median, 46 years). Striking extramedullary involvement was evident at initial presentation, with peripheral lymphadenopathy and/or mediastinal masses. Two lacked any leukemic cells in the bone marrow at diagnosis. Using cytochemical myeloperoxidase staining, less than 3% of the leukemic cells showed positive reactivity. However, expression of CD7, CD33, CD34, CD56, and frequently HLA-DR, but not other NK, T-cell, and B-cell markers was observed. Cytoplasmic CD3 was detected in three of the cases by flow cytometry and in six by Northern blotting, suggesting an origin from common progenitors between the NK cell and myeloid lineages. All but one presented germline configurations of the T-cell receptor β and γ chain genes and Ig heavy chain gene. With regard to morphology, the cells were generally L2-shaped, with variation in cell size, round to moderately irregular nuclei and prominent nucleoli, pale cytoplasm, and a lack of azurophilic granules. Histopathologic examination of biopsied specimens of extramedullary tumors showed a lymphoblast-like morphology, implying the differential diagnostic problem from lymphoblastic lymphomas, especially in cases lacking bone marrow involvement. Three patients were successfully treated with chemotherapy for acute myeloid leukemia (AML), whereas three other patients proved refractory to chemotherapeutic regimens for lymphoid malignancies, although two responded to subsequent AML chemotherapy. However, despite intensive chemotherapy, including allogeneic bone marrow transplantation, most persued fatal courses within 41 months. These data suggested that the CD7+ and CD56+ myeloid/NK cell precursor acute leukemia might constitute a distinct biologic and clinical disease entity. Its recognition appears to be particularly important for the clinicopathologic evaluation of CD56+ hematolymphoid malignancies and the development of therapeutic approaches to such disease.

Lymphoma of the nasal cavity and paranasal sinuses: improved outcome and altered prognostic factors with combined modality therapy

BACKGROUND

Lymphoma of the nasal cavity and paranasal sinuses is a rare presentation of extranodal lymphoma with a natural history that is not well characterized in this era of combination chemotherapy. The goals of this retrospective study were 1) to define the natural history of sinonasal lymphomas; 2) to compare the results of radiation therapy (XRT) alone with those of combined modality therapy (CMT) in the treatment of patients with lymphoma of the nasal cavity and paranasal sinuses; and 3) to define prognostic factors for each treatment.

METHODS

Between 1947 and 1993, 70 patients with newly diagnosed lymphoma of the nasal cavity and paranasal sinuses were treated. The Ann Arbor stages were: Stage IE: 42 patients; Stage IIE: 14 patients; Stage IIIE: 2 patients; and Stage IV: 12 patients. The distribution of T classifications of the primary tumors was as follows: T1: 2 patients; T2: 16; T3: 18; and T4: 34. Greater than 90% of the patients had intermediate grade lymphoma (Working Formulation), and none had follicular lymphoma. Twenty-eight patients received XRT alone, and 42 received CMT.

RESULTS

The actuarial 5-year freedom from progression (FFP) and overall survival (OS) rates for the entire group were 57% and 52%, respectively. For patients with localized disease (Stages IE and IIE) receiving CMT, the actuarial 5-year FFP and OS were 83% and 67%, respectively. In multivariate analysis, treatment with CMT (P = 0.0005) and stage (IE vs. IIIE-IV) (P = 0.0001) were associated with improved FFP. In the group of patients receiving XRT, extent of disease (Stage IE, T1-3 vs. Stage IE, T4 vs. Stage IIE-IV) (P = 0.0001) was the only clinical characteristic associated with improved FFP in multivariate analysis. For patients receiving CMT, International Index (0 vs. 1-3 vs. 4, 5) (P = 0.0001) was the only significant factor predictive of improved FFP in multivariate analysis. One patient failed in the central nervous system (CNS) after initial therapy as a result of a radiation therapy marginal miss.

CONCLUSIONS

In a Western population, patients with localized lymphoma of the nasal cavity and paranasal sinuses have a favorable prognosis when treated with CMT. FFP is significantly improved by treatment with CMT. For patients treated with XRT, extent of disease is the strongest predictor of outcome. International Index is the most significant prognostic factor for patients receiving CMT. Failure in the CNS is rare after initial therapy and is associated with local failure.

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.

Nasopharyngeal lymphomas: further evidence for a natural killer cell origin

The authors report four cases of sinonasal lymphomas with immunophenotypic (four cases) and genotypic (three cases) studies. These lymphomas are frequent in Oriental countries, but unusual in Western populations, particularly in France. Although they have been originally considered as T-cell lymphomas, their origin remains unclear, and several authors have recently suggested that they are a natural killer (NK)-cell proliferation. The tumor cells of the four cases reported here showed characteristics of NK cells. On cryostat sections, they were CD3 negative, but CD2 and CD56 positive. The cytoplasm of the tumor cells exhibited azurophilic granulations. Using polymerase chain reaction (PCR), no clonal rearrangement of the T-cell receptor gamma gene was present. Furthermore, clinically, two presented a pharyngeal involvement, and two were also characterized by hepatosplenic involvement at the time of the diagnosis. Thus, the present cases provide additional evidence toward the NK-cell origin of these rare lymphomas. Many sinonasal lymphomas, including the present cases, are positive for Epstein-Barr virus (EBV) (LMP-1 antibody and EBER-messenger RNA probes). This may suggest an important role of EBV as a local factor in their pathogenesis.

Nasal T-cell lymphoma causally associated with Epstein-Barr virus: clinicopathologic, phenotypic, and genotypic studies

BACKGROUND

The authors have previously demonstrated nasal T-cell lymphoma (NTL) associated with Epstein-Barr virus (EBV). The detailed clinical, phenotypic, and genotypic features and the role of EBV in lymphomagenesis remain to be clarified.

METHODS

The study group consisted of 18 patients with NTL. The phenotype was determined by immunoperoxidase staining with various monoclonal antibodies. Genotypic study was done using Southern blot hybridization. The presence of EBV-encoded small nuclear early region (EBER) RNA and EBV DNA were determined by in situ hybridization. The expression of EBV-encoded nuclear antigen (EBNA) and latent membrane protein (LMP1) were identified by immunohistologic methods. Clonotypic analysis of EBV genomes was performed by Southern blot hybridization with EBV termini fragment probe.

RESULTS

The clinical features of NTL were characterized as prolonged fever (16 patients), widespread dissemination into distant sites (13 patients), and poor prognosis with a median survival of only 6 months. EBER transcripts were identified in 16 of 18 patients. Monoclonal EBV genomes EBNA1 and LMP1 were also detected in all EBER-positive cases tested. All 18 patients expressed pan-T antigens such as MT1, CD45RO, and/or CD2. The rearrangements of T-cell receptor (TCR)-beta, -gamma, and/or -delta genes were shown in all 11 patients tested. The natural killer (NK) cell phenotype CD56 was expressed in all EBV-positive cases tested, and was not detected in EBV-negative cases. Seven EBV-positive cases expressed a TCR-delta chain with rearranged TCR-gamma or -delta genes whereas both EBV-negative cases corresponded to alpha beta T-cell lymphoma, which expressed a TCR-beta chain with a rearranged TCR-beta gene.

CONCLUSIONS

These data suggest that EBV-positive NTL may be derived from the lineage of NK-like T-cells or gamma delta T-cells, and that EBV may play a role in lymphomagenesis. Therefore, we propose that NTL which has peculiar clinical and histologic features could be classified as a new lymphoma entity.

Report of the Workshop on Nasal and Related Extranodal Angiocentric T/Natural Killer Cell Lymphomas. Definitions, differential diagnosis, and epidemiology

A workshop jointly sponsored by the University of Hong Kong and the Society for Hematopathology explored the definition, differential diagnosis, and epidemiology of angiocentric lymphomas presenting in the nose and other extranodal sites. The participants concluded that nasal T/natural killer (NK) cell lymphoma is a distinct clinicopathologic entity highly associated with Epstein-Barr virus (EBV). In situ hybridization for EBV an be very valuable in early diagnosis, especially if tissue is sparse. The cytologic spectrum is broad, ranging from small or medium-sized cells to large transformed cells. Histologic progression often occurs with time. Necrosis is nearly always present, and angioinvasion by tumor cells is seen in most cases. Nasal T/NK cell lymphoma has a characteristic immunophenotype: CD2-positive, CD56-positive, but usually negative for surface CD3. Cytoplasmic CD3 can be detected in paraffin sections. Clonal T-cell receptor gene rearrangement is not found. Tumors with an identical phenotype and genotype occur in other extranodal sites, most commonly in the skin, subcutis, and gastrointestinal tract, and should be referred to as nasal-type T/NK cell lymphomas. The differential diagnosis includes lymphomatoid granulomatosis, blastic or monomorphic NK cell lymphoma/leukemia, CD56-positive peripheral T-cell lymphoma, and enteropathy-associated T-cell lymphoma.

Experience of radiotherapy in lethal midline granuloma with special emphasis on centrofacial T-cell lymphoma: a retrospective analysis covering a 34-year period

Lethal midline granuloma (LMG) is characterized by progressive ulceration and destruction of the midfacial tissue. It occurs more frequently in Oriental than in Western populations. Because of the progress in clinical pathology and immunohistochemistry, most cases have been proven to be malignant lymphomas, especially of T-cell lineage. We describe 92 cases of lethal midline granuloma or centrofacial malignant lymphoma in the period 1959-1993. All received complete courses of radiotherapy. Twenty of them also received combination chemotherapy. Thirty-six cases had specimens available for immunohistochemical study; 25 (69%) of these had a T-cell phenotype, and 6 (17%) were of B-cell lineage. The dose to the nasal region was in the range of 3000-7500 cGy in 11-58 days, and to the neck 3000-6400 cGy in 11-48 days. The overall survival rate for the LMGs was 59.5% at 5 years and 56.2% at 10 years (Kaplan-Meier). Combined chemotherapy seemed not to improve the overall survival in this study (p = 0.63), but the patient number was too small to make a firm conclusion. Based on the results of this study, we recommend a dose of 4500-5000 cGy to the midfacial region, since a higher dosage did not improve the treatment results (p = 0.88). Irradiation has a definite role in good locoregional control of this disease. The recent clarification of the disease nature and the recognition of the background clinicopathological features should provide valuable information for future patient management and prospective studies.

Epstein-Barr virus (EBV) in extranodal T-cell non-Hodgkin's lymphomas (T-NHL). Identification of nasal T-NHL as a distinct clinicopathological entity associated with EBV

T-cell Non-Hodgkin's lymphomas (T-NHL) can be defined as clonal malignant proliferations related phenotypically and functionally to normal T-cell populations of the lymphoid tissue. There is increasing evidence that T-NHL with similar morphology but originating from different sites differ in their clinical behaviour, immunophenotypic features, oncogene expression and relation with oncogenic viruses such as HTLV-I and EBV. Indeed, it has been shown that the prevalence of EBV in T-NHL is related to the site of origin. Thus, EBV was found in nearly all nasal T-NHL but only in a proportion of primary nodal, lung, gastrointestinal and Waldeyer's ring T-NHL while it was undetectable in most primary cutaneous T-NHL. Besides their constant association with EBV, nasal T-NHL display peculiar clinical, histological, immunophenotypic and genotypic features. They present clinically as lethal midline granuloma and histologically as pleomorphic malignant tumours variably associated with angiocentricity, angioinvasion and necrosis. Moreover, they frequently exhibit extensive loss of T-cell antigens, including CD3 and TCR alpha beta and gamma delta proteins, usually express the Natural Killer (NK)-related CD56 antigen and frequently show absence of clonal rearrangements of TCR beta, gamma and delta loci. Therefore, among T-NHL, nasal T-NHL can be regarded as a distinct clinicopathologic entity associated with EBV, which could be derived either from immature T-cells or from NK cells.

Nasal T-cell lymphoma

Nasal T-cell lymphomas represent a controversial subset of malignant lymphomas and include lesions previously termed midline malignant reticulosis, lymphomatoid granulomatosis, and polymorphic reticulosis. Nasal T-cell lymphomas are rare in Western populations and much more prevalent in Asian countries. Clinically, adult males are most often affected. Histologically, an angiocentric infiltrate composed of a spectrum of atypical cells is usually present. Phenotypically, the neoplastic cells lack expression of B-lineage markers, and usually express the T-lineage-associated markers CD2, CD45RO, and CD43; however, they often lack other pan-T-lineage markers. They often express the natural killer marker CD56, but usually lack the natural killer markers CD16 and CD57. Gene rearrangement studies have shown a germline configuration for the antigen receptor genes in the majority of cases. To date, evidence of Epstein-Barr virus has been consistently demonstrated, regardless of the geographic region studied. In situ hybridization studies have localized the Epstein-Barr virus to the atypical cells.

Sinonasal malignant lymphoma of natural killer cell phenotype associated with diffuse pancreatic involvement

We report a case of sinonasal lymphoma with a natural killer (NK) phenotype. This 40-year-old man was admitted to our hospital because of left nasal obstruction. Physical examination and computed tomography of the skull revealed a tumor in the left nasal cavity and maxillary sinus. Histopathological examination revealed a diffuse proliferation of pleomorphic lymphoid cells. Imprint cytology showed that tumor cells contained some azurophilic granules, and expressed CD2, CD8, CD16, CD56 and HLA-DR antigens with little expression of other lymphoid or myeloid markers. Southern blot analysis revealed germline configuration for immunoglobulin heavy chain and T-cell receptor genes. These findings indicated that these cells were in fact NK cells. The patient's enlarged pancreas was also involved by lymphoma and the pattern of involvement simulated that seen in primary pancreatic lymphoma. Ulcerative colitis (UC) was also present, a rare finding in this disorder.

Lymphomas of the head and neck. 1: Nasofacial T-cell lymphoma

Nasofacial T-cell lymphoma includes diseases otherwise called "lethal midline granuloma" and "necrosis with atypical cells". It is characterised by relentless destruction of nose and palate in particular but the lymphoma remains localised to the head and neck. The age of onset ranges from 10 to 87 and the survival ranges from a few months to several years. The histological appearances are of a polymorphic infiltrate but including atypical T cells in a background of macrophages. There is a strong association with Epstein-Barr virus infection.

Midline malignant B-cell lymphoma with leukemic transformation

This article presents a case of lethal midline granuloma on the palate of a 44-year-old woman, which had been identified histologically as B-cell lymphoma with leukemic transformation in the terminal stages. At the first visit, physical and laboratory examinations showed no remarkable findings except for a necrotizing ulcer of the palate, and the biopsy specimens only showed massive inflammatory cell infiltration and necrosis of the granulation tissue. There was a short-term resolution after treatment with cyclophosphamide and prednisolone, but the disease reactivated and the necrotic ulcerative lesion progressively advanced into the nasal cavity. Specimens from the third biopsy exhibited histologic features that were consistent with malignant lymphoma of the diffuse, mixed B-cell type. Chemotherapy with the regimen of cyclophosphamide, doxorubicin, vincristine, and prednisolone was adopted but was interrupted after a short time because of bone marrow suppression. Subsequently, large numbers of enlarged abnormal lymphocytes with a few vacuoles in the cytoplasm appeared in the circulating blood, indicating leukemic transformation of the midline lymphoma. The patient died on the seventh day after the initiation of chemotherapy. In the presentation of this case, the authors mention clinically important matters regarding midline lethal lymphoma and briefly discuss the pathophysiology and pathogenesis.

B-cell lymphoma presenting as a midfacial necrotizing lesion

A case of midfacial necrotizing lesion (midline nonhealing granuloma) is reported. Paraffin- and frozen-section immunocytochemistry suggested a tumor of B-cell lineage and was confirmed by Southern blot analysis that disclosed an immunoglobulin heavy chain gene rearrangement with no evidence of T-cell receptor genetic aberration. The tumor was of B-cell lineage despite the tumor site and the angiocentric pattern, which are typically seen with peripheral T cell lymphoma with this presentation.

Lethal midline granuloma (peripheral T-cell lymphoma) after lymphomatoid papulosis

A Japanese woman with an 8-year history of lymphomatoid papulosis (LP) had lethal midline granuloma (LMG) develop at the age of 51 years. There were histologic similarities between LP and LMG seen in this patient. Surface phenotypic studies on nasal and cutaneous lesions demonstrated a population of T-cells expressing CD2, CD4, CD25, CD30, and histocompatibility antigen-DR (HLA-DR). Genotypic analyses of nasal and skin biopsy specimens disclosed a clonal rearrangement of the beta T-cell receptor gene with the same rearrangement pattern. These data indicate that this patient had LMG characterized by clonal peripheral T-cell lymphoma, which probably resulted from progression of the LP.

Clinicopathological spectrum of Epstein-Barr virus-associated T cell malignancies

It has been recently demonstrated that the Epstein-Barr virus (EBV) can infect human thymocytes and may be involved in the T cell neoplasms, in addition to African Burkitt's lymphoma, nasopharyngeal carcinoma and Hodgkin's disease. Four distinct clinicopathologic categories of EBV-associated T cell malignancies have been recognized. The angiocentric T cell lymphoma or lymphomatoid granulomatosis involving the nose (or midline lethal granuloma) and skin is frequently EBV-associated. The other 3 groups include angioimmunoblastic lymphadenopathy-like lymphoma, node-based T immunoblastic lymphoma which may contain Reed-Sternberg-like giant cells (Hodgkin's-like lymphoma), and T cell lymphoma resembling malignant histiocytosis. Both the CD4 and CD8 T cell subsets, and a hitherto undefined T lineage lacking CD4/CD8 expression have been involved. The common clinical features are prolonged fever, skin lesions, lymphadenopathy, hepatosplenomegaly, and pancytopenia. Serologic assays suggest that a chronic active EBV infection may exist in most of these patients. The EBV genomes appear to proliferate in clonal and episomal form in the neoplastic cells which show expression of latent membrane proteins. Although an indolent local phase may exist, the clinical course is aggressive for most patients with frequent development of drug resistance to conventional chemotherapy. EBV-associated T cell lymphoma constitutes a separate entity of virus-associated human diseases and opens a potential field to investigate the pathogenesis of EBV-associated human malignancies.

Lethal midline granuloma: impact of imaging studies on the investigation and management of destructive mid facial disease in 13 patients

In 13 patients presenting as lethal midline granuloma (LMG), computed tomography proved essential for determining the extent of the disease, guiding biopsy and planning radiotherapy. Magnetic resonance imaging (MRI) was also helpful for the latter, because it could distinguish fluid retained within the paranasal sinuses from solid masses and tumour from granulation tissue; it was of little value for detecting bone lysis. Eight of the 13 patients proved to have T-cell lymphoma, two had Crohn's disease, in one the lesion was factitious and two had granulomas without diagnostic histological features.

Non-Hodgkin's lymphoma confined to the nasal cavity: its relationship to the polymorphic reticulosis and results of radiation therapy

From 1975 through 1988, nine patients with locally confined nasal non-Hodgkin's lymphoma (NHL) were treated with radiation therapy in the Department of Radiology, Chiba University Hospital. Immunohistochemical study disclosed that all NHL's have T-lineage. Additionally, unique histological pictures of polymorphism, angiodestruction, and necrosis were seen in most of cases. These three findings are the histological features of polymorphic reticulosis (PMR), which is the main cause of lethal midline granuloma and has recently been shown to belong to T-cell malignancy. Therefore, it is concluded that the nasal T-cell NHL and PMR are really a single disease entity. The predominance of the T-cell lymphoma in the nasal cavity as well as its histological distinctness clearly indicate that the head and neck extranodal NHL cannot be discussed together. Although the disorder was considered to be locally limited at presentation, only 3 of the 9 patients with nasal NHL could be induced into long-term remission with involved field radiotherapy. The distant extranodal spread was the primary cause of failure. Multimodality treatment using intensive chemotherapy might improve the prognosis of nasal NHL.

Polymorphic reticulosis and conventional lymphomas of the nose and upper aerodigestive tract: a clinicopathologic study of 70 cases, and immunophenotypic studies of 16 cases

Seventy patients with malignant lymphomas, including the entity known as polymorphic reticulosis (PR), involving the nose, nasal sinuses, nasopharynx, oropharynx (excluding tonsil), and larynx were studied. There were 26 cases of PR, 19 cases of lymphoma with features of PR (ML[PR]) and 25 cases of conventional lymphomas. Fourteen of the 25 conventional lymphomas were due to dissemination from distant sites. For all histologic types of primary lymphoma, the presenting symptoms were similar, and the nasal cavity was more commonly involved than the nasopharynx. Patients with PR were younger, had a higher male:female ratio, and had a better overall survival rate than patients with conventional lymphomas. Cryostat section immunohistochemistry performed on 17 samples from 16 patients showed only one B lymphoma out of 11 primary lesions; the other 10 cases and three recurrent tumors at distant sites showed phenotypic markers of T lymphocytes and natural killer cells. All three secondary tumors were of B-cell type. Of eight patients with sequential biopsies, progression to a more malignant histopathologic type was found in six. In the PR and ML[PR] biopsies, angiocentricity was detected in 11%, and angioinvasion in 22%. We could not confirm identity of PR with other angiocentric immunoproliferative lesions.

Presence of Epstein-Barr virus DNA in nasal lymphomas of B and 'T' cell type

We studied 12 tumours from 11 Chinese patients with primary nasal lymphoma for presence of Epstein-Barr Virus (EBV) DNA, using Southern-blot analysis. These results were correlated with immunophenotype and T-cell receptor (TcR) or immunoglobulin gene rearrangement patterns. EBV DNA was detected in all nine tumours with a 'T' phenotype, in both primary and secondary sites. When the structure of the viral genomic termini was studied using the EcoRI-Dhet probe, a single clonal episomal band was demonstrated in five tumour samples, with one other case showing a biclonal pattern. However, none of these cases showed clonal rearrangement of TcR beta chain gene, and TcR gamma rearrangement was found only in one. The lineage of these phenotypic 'T' lymphomas therefore require further studies for confirmation. Two out of three B-lymphomas were also EBV DNA+; clonal EBV DNA was found in one. Their B-lineage was confirmed by detection of clonal immunoglobulin gene rearrangements. The association of EBV with an increasing number of lymphomas of different types highlights the need for continued study into its role in oncogenesis.

Association of Epstein-Barr virus with polymorphic reticulosis

We report a case of polymorphic reticulosis (PR) associated with pharyngeal replication of Epstein-Barr virus (EBV). A 78-year-old man with necrotic inflammatory granulations in the nasal cavities and ulcerative tissue of the tonsils was found to have PR after an initial diagnosis of lethal midline granuloma and was found to have high antibody titers to EBV. EBV-determined nuclear antigen (EBNA) was demonstrated in pharyngeal biopsy specimens by the anti-complement immunofluorescent technique, following which dual immunofluorescence staining, EBNA and T-cell antigen analysis were performed, using a wide variety of monoclonal antibodies. All of the EBNA-positive lymphocytes in the pharyngeal biopsy specimens were found to have exclusively T-cell antigens. This case strongly suggests that some of the cases of PR related to T-cell lymphomas may be closely associated with active EBV infection.

Epstein-Barr virus in nasal T-cell lymphomas in patients with lethal midline granuloma

Five cases of lethal midline granuloma were identified histologically and phenotypically as peripheral T-cell lymphomas. Epstein-Barr virus (EBV) DNA was detected in the nasal tumour biopsy specimens by Southern blotting and in-vitro hybridisation with simultaneous detection of EBV-determined nuclear antigen (EBNA) and T-cell surface markers by two-colour immunofluorescence. Further immunofluorescence and northern blotting revealed that EBNA2 gene and also latent membrane protein gene were expressed in the nasal tumour cells. The patients had high titres of antibodies to EBV. These findings suggest that lethal midline granuloma is causally associated with EBV.

CT evaluation of polymorphic reticulosis

For the understanding of the CT findings of polymorphic reticulosis involving the upper respiratory tract, we reviewed eleven cases of this disease with initial CT study before treatment. CT revealed masses or swelling in the nose or nasal chamber, often with involvement of paranasal sinuses and medial parts of the orbit. In some, nonspecific minimal bony change (either bone destruction or bone sclerosis) was found. These CT findings are not specific. Any large mass in the nose and nasal fossa with little associated bone destruction should, however, raise the differential diagnosis of polymorphic reticulosis.

Cutaneous relapse of nasal T-cell lymphoma clinically mimicking erythema multiforme

Lymphomatous involvement of skin usually manifests as plaques, maculopapules, papulonodules, tumorous masses or ulcerated eruptions. We report an unusual case in which the cutaneous relapse of nasal T-cell lymphoma clinically mimicked erythema multiforme by the abrupt onset of lesions and the presence of targetoid and vesicular lesions. Histologically, the lymphomatous involvement was predominantly periadnexal, with destructive infiltration of blood vessels, nerves and sweat glands. Early biopsy of all unexplained cutaneous eruptions in patients with malignant lymphoma is therefore recommended.

Immune deficiency with polymorphic reticulosis

A case of fatal polymorphic reticulosis, currently considered to be a peripheral T cell lymphoma, that was initially seen as a nasolabial swelling with a left lower lobe pulmonary nodule in a 40-year-old woman is reported. At autopsy, it was found to be associated with disseminated cryptococcosis and Pneumocystis carinii pneumonia associated with secondary severe immunodeficiency of unknown origin.

Primary lymph node presentation of angiocentric lymphoma associated with features of a hemophagocytic syndrome

The spectrum of post-thymic T-cell neoplasia includes the angiocentric immunoproliferative lesions, a group of disorders histologically exhibiting vascular infiltration and destruction; included among these disorders is angiocentric lymphoma. In contrast to the typical extranodal presentation seen in the angiocentric immunoproliferative lesions, this report describes a case of angiocentric lymphoma presenting as primary lymph node disease with clinicopathologic findings mimicking a hemophagocytic syndrome. Rearrangement of the T-cell receptor beta chain documents this case to be a clonal T-cell neoplasm. The association of this distinct histologic type of T-cell malignancy with hemophagocytic syndromes is reviewed.

Malignant lymphomas of the nasal cavity and paranasal sinuses

The incidence of malignant lymphomas in the nasal cavity and paranasal sinuses was found to be 0.17% of all malignant lymphomas and 0.44% of all extranodal malignant lymphomas registered in the Kiel Lymph Node Registry from 1972 to 1987. Fifty-nine cases of malignant lymphoma presenting in the nasal cavity and paranasal sinuses were investigated with morphological and immunological methods. The median age of the patients was 64.5 years, with a female predominance (m:f = 0.87:1). In the 59 cases a marked preponderance of B-cell lymphomas was found (centroblastic n = 15, immunoblastic n = 8, Burkitt's lymphoma n = 6, Immunocytoma n = 3, centrocytic n = 1, centroblastic/centrocytic n = 1, plasmacytic n = 11); only a small number (n = 5) was of T-cell lineage (pleomorphic types). Nine further cases could not be assigned with certainty to either the T or B cell system. Angiocentricity with infiltration and destruction of vessel walls by tumour cells was demonstrated only in the T-cell lymphomas; the B-cell lymphomas, in contrast, often surrounded and compressed blood vessels with intact endothelium. No similarity to malignant lymphomas of mucosa associated lymphoid tissue, such as those in the gastrointestinal tract, was detected.

Heterogeneous malignant non Hodgkin's lymphomas as a causative disorder in lethal midline granuloma

The present report describes the results of a combined morphological, enzyme- and immunohistochemical analysis of nine cases of malignant non Hodgkin's lymphomas (NHL) clinically presenting as lethal midline granuloma. In a previous report written before antibodies directed against B and T lymphocytes were available, a histiocytic origin of such neoplasms had been suggested. A panel of antibodies reactive with most B cells (L26, MB1, KiB3) and a majority of T cells (MT1, UCHL1) was applied on paraffin sections of formalin fixed tissues as well as antibodies directed against leukocyte common antigen (LCA), myeloid/histiocyte antigen (MAC 387), lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, S-100 protein, prekeratin and immunoglobulin light chains. Enzyme histochemistry included tests for non-specific acid esterase, acid phosphatase, beta-glucuronidase and chloroacetate esterase. As a result, five T, two B and two unclassified (malignant histiocytosis probable) NHL were identified, indicating distinct heterogeneity of NHL as causative disorders in lethal midline granuloma.

Peripheral T cell lymphoma presenting primarily as lethal midline granuloma

This clinicopathologic study reports seven patients who primarily presented with ulcerative and destructive lesions of the upper aerodigestive tract and face, clinically consistent with so-called lethal midline granuloma (LMG). Histologically, the infiltrates were composed of atypical lymphoid cells that displayed angiocentricity and angiodestruction. In five patients, involvement of distant sites such as skin, lungs, lymph nodes, and bone marrow occurred, and in two cases, the disease remained localized. Immunomorphologic analysis, using monoclonal antibodies to frozen and paraffin sections, provided evidence for the diagnosis of peripheral T cell lymphoma (PTL) in all cases. The midline tumors were classified as diffuse mixed or diffuse large cell lymphoma occurred at distant sites. According to modern PTL classification systems, the lesions could be classified as pleomorphic T cell lymphomas. Those five patients who presented with or progressed to large cell lymphoma died within 18 months (mean, 7 months), whereas the two patients with localized disease are alive after 10 and 36 months, respectively. The size of the atypical lymphoid cells may be of prognostic significance since the large cell compartment seems to represent the major growth fraction in these PTLs.

Lethal midline granuloma (polymorphic reticulosis) and lymphomatoid granulomatosis. Evidence for a monoclonal T-cell lymphoproliferative disorder

Lymphomatoid granulomatosis (LG) and polymorphic reticulosis (PR), originally described as distinct entities, now are considered as a single disease process. Common histopathologic features include necrosis, vasculitis, and a granulomatous infiltrate. Such features have led to consider lymphomatoid granulomatosis as a systemic vasculitis; alternatively the possible emergence of an overt lymphoma has suggested that it could be a lymphoproliferative process. To investigate this later hypothesis, the authors analyzed the cellular infiltrate of tissue specimens from two patients with histologic features of LG. The analysis included the study of T-cell antigen expression and DNA rearrangement of the beta T-cell receptor gene. In one patient, the T-cell phenotype of infiltrating cells was abnormal because of antigen loss. In both patients, the cells contained rearranged DNA indicating the presence of a clonal T-cell proliferation. It is concluded that some cases of LG and PR, if not all, are related to a neoplastic T-cell lymphoproliferative disorder.