Common germinal-center B-cell origin of the malignant cells in two composite lymphomas, involving classical Hodgkin's disease and either follicular lymphoma or B-CLL.

BACKGROUND: Classical Hodgkin's disease (HD) and B-cell non-Hodgkin lymphoma (NHL) occasionally occur in the same patient. Such composite lymphomas represent interesting models to study the pathogenesis of B-cell lymphomas and the relationship between HD and B-cell NHL. MATERIALS AND METHODS: We analyzed two composite lymphomas (a combination of classical HD with follicular lymphoma [FL] and a combination of classical HD with B-cell chronic lymphocytic leukemia [B-CLL]) by micromanipulation of single cells from tissue sections and amplification of immunoglobulin V region genes for the clonal relationship of the tumor cells. RESULTS: In both cases, clonally related variable (V) genes with both shared as well as distinct somatic mutations were obtained from the two lymphomas, showing that in each of the cases the distinct tumor cells were members of a common germinal center (GC) B-cell clone. FL cells from two different lymph nodes of patient 1 showed a similar mutation pattern, suggesting that infiltration of these lymph nodes by tumor cells was not restricted to a particular FL cell or subclone. In the FL, a single cell was identified with a mutation signature indicating that premalignant cells can persist in the tissue. CONCLUSIONS: The cases presented here further underline the close relationship between HD and B-cell NHL and the role of the GC in lymphomagenesis. Whereas the latter was already suggested for FL and HD, the present study indicates that also in the B-CLL subset characterized by mutated Ig genes, important steps in malignant transformation happen in the GC, and that HRS cells can derive from CD5-positive B cells.

Pathologic and clinical features of primary pulmonary extranodal marginal zone B-cell lymphoma of MALT type.

We reviewed pathologic, phenotypic, and clinical features of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type primarily involving lung to address unresolved questions regarding behavior and pathologic features of unambiguously diagnosed pulmonary MALT lymphoma. Lung specimens from 50 patients were reviewed. Forty-one had low-grade MALT lymphoma. Nine had low-grade MALT lymphoma and diffuse large B-cell lymphoma. The patients included 32 women and 18 men with a median age of 68 years (range 34-88 years). Half of the patients were asymptomatic at the time lymphoma was diagnosed. Radiographic abnormalities were more commonly unilateral (37 patients) than bilateral (12 patients). Localized masses or nodules occurred in 39 patients. Associated autoimmune disorders (29%) and monoclonal gammopathies (43%) were common. Low-grade lymphomas formed intraparenchymal masses composed of centrocyte-like cells, plasmacytoid lymphocytes, and plasma cells that formed lymphoepithelial lesions and exhibited a lymphangitic growth pattern. Mediastinal lymph nodes were involved histologically in 44% of cases. Lymphoma-specific survival was 71.7% at 10 years, and overall survival was significantly worse than age-and gender-matched control patients. None of the following features predicted those patients who had an adverse outcome: systemic symptoms, presence of autoimmune disorders or paraproteinemia, anatomic distribution and number of pulmonary lesions, lymph node involvement, or presence of anthracycline-treated large B-cell lymphoma.

Immunoglobulin heavy-chain gene rearrangement studies by Southern blot using DNA extracted from formalin-fixed, paraffin-embedded tissue.

BACKGROUND: In most clinical molecular diagnostics laboratories, Southern blots for gene rearrangement studies are not routinely performed on formalin-fixed, paraffin-embedded (FFPE) tissue samples. In this study, immunoglobulin heavy-chain gene rearrangements by Southern blot using DNA extracted from FFPE tissue samples were studied. METHODS AND RESULTS: Eleven paired freshly frozen and FFPE tissue samples were evaluated for immunoglobulin gene rearrangements by PCR and Southern blot analyses. An additional 14 selected samples sent to our laboratory to rule out lymphoma, for which only FFPE tissue (no frozen tissue) was available and for which PCR was interpreted as negative, were evaluated by the same techniques. Southern blots generated from DNA extracted from FFPE tissues were qualitatively identical to those generated from DNA extracted from fresh or freshly frozen tissue and correlated well with the final diagnoses. Ten interpretable Southern blots were generated in the 14 cases in which no frozen tissue was available. Four of these ten blots were interpreted as positive for an immunoglobulin gene rearrangement. Although the number of samples analyzed is small, success with Southern blotting correlated with increased sample size and sample width (1.17 vs 0.49 cm(2); P <.024; 0.71 vs 0.43 cm; P <. 049, respectively). CONCLUSION: DNA extracted from FFPE tissue samples using the simple, efficient, and nontoxic techniques described in this report can be used in many cases for Southern blotting for the detection of clonality by gene rearrangement studies.

Detection of t(2;5) in anaplastic large cell lymphoma: comparison of immunohistochemical studies, FISH, and RT-PCR in paraffin-embedded tissue.

Anaplastic large cell lymphoma (ALCL) is associated with the t(2;5)(p23;q35) translocation involving the anaplastic lymphoma kinase gene (ALK) and the nucleophosmin gene (NPM), which result in expression of a novel fusion protein, NPM-ALK (p80). Clinicopathologic studies have shown that ALK expression in ALCL is associated with improved 5-year survival rates when compared with ALCL lacking ALK expression. This study used paraffin-embedded tissue to compare interphase fluorescence in situ hybridization (FISH) and reverse transcriptase-polymerase chain reaction (RT-PCR) for the detection of t(2;5) with immunohistochemical analysis for the detection of ALK protein expression in 27 patients with CD30-positive ALCLs. ALK protein expression was detected with ALK1 antibody in 14 of the 27 patients. The neoplastic cells in 13 of these 14 lymphomas reacted with the p80NPM/ALK antibody. FISH, using a two-color ALK DNA probe, correlated 100% with the immunohistochemical results: a translocation involving the ALK gene was detected in all 14 lymphomas that reacted with anti-ALK1. RT-PCR, performed on 21 lymphomas, detected NPM-ALK mRNA in five of the lymphomas, all of which reacted with anti-ALK1 and showed ALK gene rearrangement by FISH. Lymphomas showing ALK1 reactivity occurred in a younger patient population (median age, 19.5 years) and were associated with improved 5-year survival rates (84%), as compared with lymphomas lacking ALK1 reactivity (median age, 68.0 years; 5-year survival rate, 35%; p = 0.008). We conclude that immunohistochemical studies, using antibody ALK1. and FISH for ALK gene rearrangement are equally effective for identifying patients with ALCL who have a favorable clinical outcome.

Molecular analysis of single B cells from T-cell-rich B-cell lymphoma shows the derivation of the tumor cells from mutating germinal center B cells and exemplifies means by which immunoglobulin genes are modified in germinal center B cells.

T-cell-rich B-cell lymphoma (TCRBCL) belongs to the group of diffuse large cell lymphomas (DLL). It is characterized by a small number of tumor B cells among a major population of nonmalignant polyclonal T cells. To identify the developmental stage of the tumor progenitor cells, we micromanipulated the putative neoplastic large CD20(+) cells from TCRBCLs and amplified and sequenced immunoglobulin (Ig) V gene rearrangements from individual cells. In six cases, clonal Ig heavy, as well as light chain, gene rearrangements were amplified from the isolated B cells. All six cases harbored somatically mutated V gene rearrangements with an average mutation frequency of 15.5% for heavy (VH) and 5.9% for light (VL) chains and intraclonal diversity based on somatic mutation. These findings identify germinal center (GC) B cells as the precursors of the transformed B cells in TCRBCL. The study also exemplifies various means how Ig gene rearrangements can be modified by GC B cells or their malignant counterparts in TCRBCL: In one case, the tumor precursor may have switched from kappa to lambda light chain expression after acquiring a crippling mutation within the initially functional kappa light chain gene. In another case, the tumor cells harbor two in-frame VH gene rearrangements, one of which was rendered nonfunctional by somatic mutation. Either the tumor cell precursor entered the GC with two potentially functional in-frame rearrangements or the second VHDHJH rearrangement occurred in the GC after the initial in-frame rearrangement was inactivated by somatic mutation. Finally, in each of the six cases, at least one cell contained two (or more) copies of a clonal Ig gene rearrangement with sequence variations between these copies. The presence of sequence variants for V region genes within single B cells has so far not been observed in any other normal or transformed B lymphocyte. Fluorescence in situ hybridization (FISH) points to a generalized polyploidy of the tumor cells.

Identification of common germinal-center B-cell precursors in two patients with both Hodgkin's disease and non-Hodgkin's lymphoma.

BACKGROUND: Hodgkin's disease and non-Hodgkin's B-cell lymphoma occasionally occur in the same patient. The identification of a common precursor of the two types of lymphoma would show definitively that Reed-Sternberg cells originate from B cells. METHODS: We studied lymphomas from two patients, one with a composite lymphoma (classic Hodgkin's disease and a follicular lymphoma in the same lymph node) and the other with a T-cell-rich B-cell lymphoma that was followed by classic Hodgkin's disease. Single Reed-Sternberg cells and non-Hodgkin's lymphoma cells from frozen sections were micromanipulated. The rearranged immunoglobulin variable-region genes (V genes) of the heavy and light chains were amplified by the polymerase chain reaction from genomic DNA and sequenced. RESULTS: In both patients, the Reed-Sternberg cells were related clonally to the non-Hodgkin's lymphoma B cells. The V genes carried somatic mutations (a hallmark of germinal-center B cells and their descendants). In both patients, some somatic mutations were shared by the Reed-Sternberg and non-Hodgkin's lymphoma cells, whereas other somatic mutations were found exclusively in one or the other cell type. CONCLUSIONS: In two patients with classic Hodgkin's disease and non-Hodgkin's B-cell lymphoma, we identified a common B-cell precursor, probably a germinal-center B-cell, for both lymphomas. This finding suggests that the two types of lymphoma underwent both shared and distinct transforming events and provides proof of the B-cell derivation of Reed-Sternberg cells in classic Hodgkin's disease.

Osseous Hodgkin disease.

BACKGROUND: Hodgkin disease rarely presents as an osseous lesion, and the majority of patients are found at staging to have concurrent disease in lymph nodes. Many cases of osseous Hodgkin disease have been misdiagnosed on initial biopsy. METHODS: All cases of Hodgkin disease diagnosed by open bone biopsy at the Mayo Clinic were identified. These included patients with primary osseous tumors, those presenting with multiple sites of involvement (with osseous lesions), and those with recurrence in bone. Recut sections were subjected to immunohistochemical stains to confirm the diagnosis. Clinical data and follow-up information were obtained from patients' charts. RESULTS: Twenty-five patients (15 males and 10 females with an average age of 37 years) with osseous Hodgkin disease were identified during the years 1927-1996. Three patients had solitary, osseous tumors and two had primary, multifocal, osseous Hodgkin disease without involvement of nonosseous sites. Twelve patients who presented with lesions in osseous sites also had nonosseous tumors detected at staging, and 8 patients had recurrent Hodgkin disease that presented in bone. The majority of patients with primary and recurrent tumors presented only with bone pain; >50% of patients with concurrent osseous and nonosseous disease also had B-type symptoms. Nearly all lesions were in the axial and proximal appendicular skeleton. Radiographic features included osteosclerotic, osteolytic, and mixed lytic/sclerotic patterns. Cortical destruction, periosteal new bone formation, and soft tissue masses were present in 50% of cases. The histologic diagnosis of osseous Hodgkin disease occasionally was problematic; osteomyelitis was the most frequent misdiagnosis. Immunohistochemical stains revealed expression of CD15 and CD30 in neoplastic cells (which were negative for CD45 and B-cell and T-cell antigens) in all but two cases. Involved lymph nodes typically exhibited nodular sclerosis Hodgkin disease. Three patients with primary solitary osseous Hodgkin disease received radiation treatment only; at last follow-up 2 patients were alive at 22 months and 10 years, respectively. Patients with concurrent osseous and nonosseous tumors exhibited a 60% overall survival rate, but at last follow-up all 4 patients diagnosed after 1986 still were alive; those with Hodgkin disease that recurred as osseous lesions had a 60% survival rate at 8 years, but only 1 of the 5 patients diagnosed since 1984 had died of disease. CONCLUSIONS: Osseous Hodgkin disease typically presents with bone pain, and the majority of patients have concurrent nonosseous lesions detected at staging. Radiographic features of osseous Hodgkin disease vary but indicate an aggressive malignant process. The histologic diagnosis may be problematic; immunohistochemical stains aid in establishing the diagnosis of Hodgkin disease in bone. Survival of patients with osseous Hodgkin disease has been found to be good for the last 10 years.

Laparoscopic biopsy for suspected abdominal lymphoma.

This study retrospectively reviewed the findings in laparoscopic biopsy specimens from 51 consecutive patients with suspected abdominal lymphoproliferative disorders. Histologic evaluation was supplemented (as necessary) by paraffin-section or frozen-section immunohistochemical analysis or by Southern blot hybridization. The laparoscopic procedure was diagnostic of a lymphoproliferative disorder in 24 patients (47%), of other neoplasms in 5 patients (10%), and of reactive tissue in 11 patients (22%); no tissue could be obtained for technical reasons (adhesions and inaccessible lesions) in 11 patients (22%). The 24 patients with lymphoproliferative disorders diagnosed by laparoscopic techniques included 14 patients with a new diagnosis of lymphoma and 10 patients with recurrent disease; pathologic findings were diagnostic of diffuse large cell lymphoma (11 patients), follicular lymphoma (11 patients), chronic lymphocytic leukemia (1 patient), and lymphocyte-predominant Hodgkin's disease (1 patient). Previous abdominal cytologic or core-needle biopsy specimens from 11 lymphoma patients did not yield an unequivocal diagnosis or subtype of lymphoma. The 11 patients (22%) in whom laparoscopic techniques did not produce a tissue sample needed laparotomy (10 patients) or femoral lymph node biopsy (1 patient) to document the diagnosis of large cell lymphoma (2 patients), follicular lymphoma (5 patients), composite lymphoma (1 patient), myeloma (1 patient), neurofibroma (1 patient), and reactive lymph nodes (1 patient). In the majority of patients with suspected abdominal lymphoma, laparoscopic techniques provide sufficient tissue for the diagnosis and classification of lymphoma and for the diagnosis of other causes of abdominal lymphadenopathy.

Epstein-Barr virus-induced T cell lymphoma in solid organ transplant recipients.

Epstein-Barr virus (EBV) infection in transplant recipients can lead to lymphomas termed posttransplantation lymphoproliferative disorders (PTLDs). Most PTLDs are malignancies of B lymphocytes and are linked to EBV infection, but the rare T lymphocyte PTLDs have been inconsistently linked to EBV infection. Although the B lymphocyte is the main host cell of EBV, it has been suggested that T lymphocytes may also become infected by EBV. A review of EBV-induced PTLDs at our institution identified one of 61 cases that was restricted to T lymphocytes. Of 36 cases of T cell PTLD identified through a literature review, 21 were investigated for the presence of EBV, and eight (38%) were documented to be EBV-induced. We compared the features of EBV-positive and EBV-negative T cell PTLDs and concluded that cases of EBV-positive T cell PTLD have some distinctive clinical features.

Primary laryngeal lymphoma.

Primary laryngeal lymphoma is a very rare entity, with fewer than 50 cases reported in the English literature in the past 60 years. Close scrutiny of some of these case reports reveals that the larynx was not always the only site of involvement, thereby diminishing the total number of patients with primary laryngeal lymphoma to fewer than 35. The authors report a series of six patients, who were seen and evaluated at the Mayo Clinic between 1952 and 1995, with stage IAE non-Hodgkin's lymphoma of the larynx. Three patients had large-cell lymphomas according to the REAL (Revised European-American Lymphoid) classification. The other three had a small lymphocytic lymphoma, follicular small cleaved lymphoma, and follicular mixed lymphoma. All patients received radiation therapy alone as initial therapy for their disease and all patients had a complete remission to initial therapy. Four patients subsequently relapsed and the histology at relapse was the same as the initial histology in all four patients. Five patients have died, three of lymphoma, with a median survival of 67 months (range, 40 to 228 months). In view of the heterogeneity of histologies in this group of lymphomas, the variability in duration of response, and the significant number of patients who died of their disease, it is more likely that primary laryngeal lymphoma is an unusual presentation of non-Hodgkin's lymphoma than a separate disease entity. Despite the small number of patients in this study, the data would suggest that patients are best treated according to the histology of the lymphoma, rather than the limited stage and location of the disease.

Adrenal insufficiency as a manifestation of disseminated non-Hodgkin's lymphoma.

OBJECTIVE: To analyze the clinical characteristics, laboratory features, and outcome in five patients who had biochemically proven adrenal insufficiency attributable to pathologically confirmed non-Hodgkin's lymphoma (NHL). MATERIAL AND METHODS: We retrospectively reviewed the medical records of all patients at Mayo Clinic Rochester during the period from 1976 to 1994 to identify those with both NHL, as listed in the surgical pathology tissue registry, and adrenal insufficiency. Histologically, the patients were classified on the basis of the working formulation and the revised European-American lymphoma classification. RESULTS: Three patients had diffuse large cell NHL, one patient had small noncleaved NHL, and one patient had cutaneous T-cell NHL. All five patients had stage IV disease. Adrenal insufficiency was confirmed by morning and evening determinations of serum cortisol levels and cosyntropin stimulation tests. All patients demonstrated loss of circadian rhythm. The median age of the patients was 77 years (range, 60 to 89). Three of the five patients died without treatment from 5 to 22 days after assessment. One patient died of a cerebrovascular accident. Despite initiation of chemotherapy, two patients died of progressive NHL at 7 weeks and 7 months. CONCLUSION: In our experience, biochemically proven adrenal insufficiency in patients with NHL is a manifestation of clinically advanced disease in elderly patients. A stepwise diagnostic approach is critical for the appropriate management of such patients.

Hodgkin and Reed-Sternberg cells in lymphocyte predominant Hodgkin disease represent clonal populations of germinal center-derived tumor B cells.

Among the four subtypes of Hodgkin disease (HD), lymphocyte-predominant (LP) HD is now generally considered as a separate entity. The B cell nature of the typical Hodgkin and Reed-Sternberg (HRS) cells and their variants (L and H, lymphocytic and histiocytic cells) in LP HD has long been suspected, but the question of whether these cells represent a true tumor clone is unclear. We previously demonstrated clonal Ig gene rearrangements in one case of LP HD. In the present study, five cases of LP HD were analyzed by micromanipulation of single HRS cells from frozen tissue sections and DNA amplification of rearranged Ig heavy chain genes from those cells. Clonal V gene rearrangements harboring somatic mutations were detected in each case. In three cases ongoing somatic mutation was evident. This shows that HRS cells in LP HD are a clonal tumor population derived from germinal center B cells. The pattern of somatic mutation indicates that HRS cells in LP HD are selected for antibody expression. This, and the presence of ongoing mutation discriminates LP from classical HD.

Splenic vascular tumors: a histologic, immunophenotypic, and virologic study.

Vascular tumors of the spleen include several different entities, some of which are unique to that organ. Twenty-two such proliferations were studied, including 10 hemangiomas, six littoral cell angiomas, four angiosarcomas, and two hamartomas. The hemangiomas included seven with localized tumors and three with diffuse angiomatosis of the spleen. All cases were studied by paraffin section immunohistochemistry with a large panel of antibodies. In addition, all cases were studied for the presence of the Kaposi's sarcoma-associated herpesvirus (KSHV) using the polymerase chain reaction. The morphologic findings were similar to those previously reported. All proliferations were vimentin positive, and one angiosarcoma was focally keratin positive. All cases reacted for CD31, whereas 20 of 22 were positive for von Willebrand's factor and 19 of 22 were positive for Ulex europeaus. CD34 expression in lining cells was identified in 10 of 10 hemangiomas, two of four angiosarcomas, and one of two hamartomas, whereas all six cases of littoral cell angioma were negative. CD68 was expressed in all cases of littoral cell angioma but was also positive in all three diffuse hemangiomas, two of seven localized hemangiomas, and two of four angiosarcomas. CD21 expression was restricted to the lining cells of littoral cell angioma, and CD8 expression was only identified in two of two hamartomas and two of four angiosarcomas. KSHV was not detected in any of the cases. These findings suggest that there are distinct immunophenotypic as well as morphologic features of splenic vascular tumors. Littoral cell angiomas have a characteristic CD34-/CD68+/CD21+/CD8- immunophenotype and hamartomas have a characteristic CD68-/CD21-/CD8+ phenotype. The frequent CD68 expression in diffuse hemangioma suggests an immunophenotypic difference from localized hemangioma of the spleen.

Follicular dendritic cell sarcoma mimicking diffuse large cell lymphoma: a case report.

Follicular dendritic cell sarcomas (FDCSs) are rare tumors arising from follicular dendritic cells in lymphoid tissue. Fewer than 20 cases have been described in the English-language literature. We describe the second case of an FDCS with primary liver involvement. The initial diagnosis was lymphoma, and appropriate treatment was prescribed. After the initial treatment failed, additional biopsy samples were obtained. Standard pathologic analysis and immunophenotyping for a panel of monoclonal antibodies were performed on formalin-fixed paraffin-embedded tissue and frozen sections. The pathologic findings were consistent with FDCS, and the specimens showed some of the characteristic pathologic features suggestive of this tumor, including multinucleation and a spindle pleomorphic morphology. The tumor cells were positive for S-100 protein, CD45, CD14, and vimentin. Because of its morphological characteristics, FDCS can be confused with other neoplastic entities, such as lymphomas and other solid tumors.

Splenic mesothelial cysts mimicking lymphagiomas.

Lymphangiomas of the spleen may occur as part of lymphangiomatosis or may represent solitary lesions. Solitary splenic lymphangiomas are described traditionally as subcapsular, multicystic proliferations that are often incidental findings. Six cases of splenic tumors with morphologic features similar to those described for solitary lymphangioma were studied using an immunohistochemical panel that included epithelial and vascular markers. None of the patients had evidence of lymphangiomatosis, and all tumors were incidental findings in splenectomy specimens. All cases demonstrated lining cells that were positive for keratin and the mesothelial cell-associated antibody HBME-1 but were negative for the vascular markers Factor VIII-related antigens, CD31, and CD34. The immunohistochemical findings are suggestive of a mesothelial derivation of these multicystic proliferations rather than representing true lymphangiomas.

Development of monoclonal gammopathy precedes the development of Epstein-Barr virus-induced posttransplant lymphoproliferative disorder.

Epstein-Barr virus (EBV)-induced posttransplant lymphoproliferative disorder (PTLD) develops in 3% to 10% of solid organ transplant recipients with a resultant mortality of up to 70%. Unfortunately, there is no current marker which identifies patients who will develop this disease. We therefore conducted a risk factor analysis of variables that might predict the development of PTLD. Specifically, since EBV may cause both PTLD and the development of monoclonal proteins (M protein), we sought to determine if the development of an M protein preceded and therefore might serve as a predictive marker of subsequent PTLD. Before and after liver transplantation, 201 patients were evaluated for the presence of urine and serum M proteins. Patients were followed to monitor the development of PTLD for a mean of 1,733 days. PTLD developed in seven patients (3.5%), three (43%) of whom died from disseminated PTLD. PTLD was classified as polymorphous in six patients and monomorphous in one patient. Fifty-seven patients (28%) developed an M protein after transplantation: five of seven patients (71%) with PTLD and 52/194 (27%) of patients without PTLD. Multivariate risk factor analysis for the development of an M protein after transplantation identified cytomegalovirus (CMV) donor seropositivity (P = 0.0002) and postoperative symptomatic CMV infection (P = 0.019) as risk factors. Whereas EBV serostatus of either the donor or recipient was not found to be a risk factor for the occurrence of either an M protein or PTLD, the development of a serum immunoglobulin M (IgM) M protein (P = 0.04) and of any urine M protein (P = 0.01) was identified by univariate analysis as being associated with the development of PTLD. Further studies are needed to determine the predictive value of M proteins as a marker for PTLD. Until such time, the development of serum or urine M protein should heighten the suspicion of developing PTLD.

Lymphoma in soft tissue: a clinicopathologic study of 19 cases.

The authors retrospectively reviewed 19 patients who presented with lymphoma as soft tissue masses, without evidence of lymph node or skin involvement. Sites of involvement included lower extremity (seven), upper extremity (six), chest wall (three), gluteal region (two), and frontal subgaleal region (one). Histological and immunophenotypic studies revealed 12 large cell lymphomas (11 B cell and one T cell), two small noncleaved cell lymphomas (B-cell phenotype), and five low grade B-cell lymphomas (two small lymphocytic and three follicular mixed lymphomas). Patients with large cell lymphoma, including seven patients with stages I and II and five patients with stage IV, were treated with anthracycline-based chemotherapy, with or without radiation therapy. One half of these patients are dead of disease, including four of seven with low stage disease. The two patients with small noncleaved cell lymphoma had stage IE disease and were treated with chemotherapy; one died at 11 months, and the other is alive and disease free at 65 months. Patients with low grade B-cell lymphoma included four stage IE patients who were treated with radiation and one stage IV patient treated with chemotherapy. Two patients are alive and disease free, and three are dead of unrelated causes. The authors conclude that malignant lymphomas initially diagnosed in soft tissues are most commonly large cell lymphomas with a B-cell phenotype.

Nasal and nasopharyngeal angiocentric T-cell lymphomas.

Thirty patients (24 mean and 6 women) with a median age of 44.5 years who had angiocentric T-cell lymphoma were studied. The neoplastic cells in each had a T-cell phenotype. Epstein-Barr virus RNA was detected in the neoplastic cells in 29 of 30 patients. The most common presenting symptom was nasal obstruction followed by purulent rhinorrhea. Patients with early presentation had only a friable nasal or nasopharyngeal mucosa; late clinical signs included septal perforation in 40%. Twenty-one of 30 patients received radiation therapy as initial treatment; 22 of 30 patients achieved a complete remission. Fifteen patients relapsed: 10 with local recurrence and 5 with systemic disease. In long-term follow-up, 10 patients were alive and disease free, 6 patients died of unrelated causes, and 12 patients died of disease.

Lymphomatoid granulomatosis. Evidence of immunophenotypic diversity and relationship to Epstein-Barr virus infection.

We studied open-lung biopsies from 17 patients with pulmonary lymphomatoid granulomatosis (LYG) using paraffin-section immunostains and Epstein-Barr virus (EBV) RNA in situ hybridization to assess the phenotype of these unique tumors and to clarify the role of EBV infection. Histologically, all cases demonstrated the characteristic mixed mononuclear cell infiltrate of lymphomatoid granulomatosis with variable numbers of cytologically atypical large lymphoid cells in a background of small lymphocytes. Paraffin-section immunostains in all cases showed a predominance of T lymphocytes. A minor population of CD20-positive large B lymphocytes was identified in 11 cases; immunoglobulin light-chain restriction was demonstrated in four of these and immunoglobulin gene rearrangements in another case. Nuclear labelling for EBV RNA was detected in 10 of these 11 cases and was confined to the population of large B lymphocytes. Staining for CD20 was absent in the remaining six cases, as was nuclear labeling for EBV RNA. However, the large atypical lymphoid cells stained for T-cell-lineage-specific antibodies in three of these cases. We conclude that some cases of lymphomatoid granulomatosis are B-cell lymphoma associated with EBV infection, whereas others are of T-cell origin and are probably unrelated to EBV infection.