Pyothorax-associated lymphoma. An unusual case with biphenotypic character of T and B cells

Cervical radiculopathy as first presentation of CD3-positive diffuse large B-cell lymphoma of the cervico-thoracic junction

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) in rare cases can presents an unusual expression of CD3 T-cell specific antigen. We report the first case of a CD3-positive DLBCL of the cervico-thoracic junction presenting with persistent cervical radiculopathy.

CASE PRESENTATION

A 74-years-old male patient presented a severe and persistent right C8 radiculopathy associated with right-sided neck pain, progressive numbness and weakness of the right arm. The symptoms prominent during the night interfering with sleep and were resistant to anti-inflammatory drugs and cervical orthosis. Spine MRI showed a solid hypointense lesion on T2-weighted images and hyperintense on STIR sequences involving the epidural space at C7, T1 and T2. The patient underwent a C7-T1 decompressive laminectomy and left T2 hemilaminectomy with resection of the epidural tissue resulting in subtotal removal. Histology showed a DLBCL germinal center B-cell lymphoma with expression of CD3 T-cell specific antigen. Then the patient underwent adjuvant radiotherapy and chemotherapy consisting of R-CHOP protocol. At last follow-up (2 years) the patient is still in good clinical status (KPS = 80) with almost complete recovery of the cervical radiculopathy.

CONCLUSIONS

To our knowledge this is the first case of DLBLC GCB-like CD3 positive to present with radiculopathy.

Characterization of Artificial Pneumothorax-Unrelated Pyothorax-Associated Lymphoma

Pyothorax-associated lymphoma (PAL) is a rare disease developing from a long-term pleural cavity inflammation. Most reported PAL cases have a history of artificial pneumothorax. However, the clinical features of artificial pneumothorax-unrelated PAL remain largely unknown. Here, we reported two PAL cases diagnosed from our center in the past ten years. One case developed from asymptomatic pyothorax after pneumonectomy with a latency of 28 years, while the other case showed a relatively short latency of one year. Then we reviewed the literature of artificial pneumothorax-unrelated PAL by searching PubMed and Google Scholar from 2007. In total, nine artificial pneumothorax-unrelated PAL cases were found, predominantly in old male with median age of 76 years (ranging from 51 to 88). Most cases were diagnosed with diffuse large B-cell lymphoma (DLBCL) (n = 8, 88.9%) and had evidence of Epstein-Barr virus (EBV) infection (n = 6, 66.7%) or tuberculous pleurisy (n = 5, 55.6%). Notably, four cases (44.4%) had short intervals (no more than two years) between pleuritis and PAL. Regarding the overall survival, one-third cases survived more than 5 years after the diagnosis of PAL. In conclusion, the features of artificial pneumothorax-unrelated PAL are comparable with the classic type of PAL, except for some patients with short duration of pleuritis, and need to be identified. Treatment guideline of DLBCL is recommended for the management of PAL.

CD3-positive diffuse large B-cell lymphoma relapses as CD3-negative large B-cell lymphoma: Loss of aberrant antigen expression in B-cell lymphoma after chemotherapy

Aberrant expression of CD3 on diffuse large B-cell lymphoma (DLBCL) is rare, and its mechanism and biological significance are currently unclear. Herein we report a case of Epstein-Barr virus-negative, CD3-positive DLBCL in a 53 year-old male, who had a remote history of renal transplantation. After standard chemotherapy, the patient was in clinical remission. He relapsed three years later, but at this time with apparent loss of CD3 expression. PCR-based IGK gene rearrangement studies demonstrated clonal amplicons with an identical nucleotide size between the primary and secondary DLBCL, confirming the clonal relationship despite their phenotypic differences. To our knowledge, this is the first case of CD3-positive DLBCL that demonstrated a loss of aberrant CD3 on relapse. The chronologic change in phenotype seen in this case suggests that the source of the patient's lymphoma relapse may arise from either a quiescent subclone without CD3 expression, or from an upstream neoplastic precursor cell.

Clinical and prognostic significance of aberrant T-cell marker expression in 225 cases of de novo diffuse large B-cell lymphoma and 276 cases of other B-cell lymphomas

Expression of T-cell markers, generally investigated for immunophenotyping of T-cell lymphomas, is also observed in several types of B-cell lymphomas, including diffuse large B-cell lymphoma (DLBCL). We previously reported that CD5 expression in DLBCL is an inferior prognostic factor in the era of rituximab. However, data regarding the frequencies, histological relevance, and prognostic importance of T-cell markers other than CD5 are currently unavailable. In the present study, we comprehensively evaluated the expression of T-cell markers (CD2, CD3, CD4, CD5, CD7, and CD8) in 501 B-cell lymphomas, including 225 DLBCLs, by flow cytometry and subsequent immunohistochemistry. T-cell markers other than CD5, such as CD2, CD4, CD7, and CD8, were expressed in 27 (5%) patients, and notably, all of these cases were classified as large B-cell lymphoma subtypes: 25 DLBCLs and 2 intravascular large B-cell lymphomas. CD5 and other T-cell markers were expressed in 15% (31/225) and 10% (25/225) of DLBCL cases, respectively. Five of them co-expressed CD5 and other T-cell markers. Retrospectively analyzing the prognostic relevance of T-cell markers in 169 patients with primary DLBCL treated with rituximab-based chemotherapy, we showed that only CD5 was a strong predictor of poor survival. This study provides information about the occurrence of T-cell markers other than CD5 in B-cell lymphomas, their frequent histological subtypes, and their prognostic significance in DLBCL. CD5 was reconfirmed as a negative prognostic marker in DLBCL patients receiving rituximab-inclusive chemotherapy, whereas T-cell markers other than CD5 were found to have no impact on clinicopathological and survival analyses.

EBV-Positive B-Cell Proliferations of Varied Malignant Potential: 2015 SH/EAHP Workshop Report-Part 1

OBJECTIVES

The 2015 Workshop of the Society for Hematopathology/European Association for Haematopathology aimed to review B-cell proliferations of varied malignant potential associated with immunodeficiency.

METHODS

The Workshop Panel reviewed all cases of B-cell hyperplasias, polymorphic B-lymphoproliferative disorders, Epstein-Barr virus (EBV)-positive mucocutaneous ulcer, and large B-cell proliferations associated with chronic inflammation and rendered consensus diagnoses. Disease definitions, boundaries with more aggressive B-cell proliferations, and association with EBV were explored.

RESULTS

B-cell proliferations of varied malignant potential occurred in all immunodeficiency backgrounds. Presentation early in the course of immunodeficiency and in younger age groups and regression with reduction of immunosuppression were characteristic features. EBV positivity was essential for diagnosis in some hyperplasias where other specific defining features were absent.

CONCLUSIONS

This spectrum of B-cell proliferations show similarities across immunodeficiency backgrounds. Localized forms of immunodeficiency disorders arise in immunocompetent patients most likely due to chronic immune stimulation and, despite aggressive histologic features, often show indolent clinical behavior.

Epstein-Barr virus-negative diffuse large B cell lymphoma with aberrant expression of CD3 and other T cell-associated antigens: report of three cases with a review of the literature

Expression of CD3 on a mature B cell neoplasm, such as diffuse large B cell lymphoma (DLBCL), is extremely rare. When it is present, it will cause diagnostic confusion since the classification of lymphoid neoplasms is largely based on immunophenotyping to determine the cell lineage. We report three cases of DLBCL with CD3 and other T cell-associated antigens. A literature search identifies 30 additional cases of DLBCL expressing CD3, with the majority (78.6 %) displaying cytoplasmic expression, while two of our cases demonstrate membranous staining. Additionally, expression of CD3 tends to be partial and weak in both our series and the reported cases. Of the 28 cases reported in the literature that were tested for Epstein Barr Virus (EBV), 16 (57.1 %) are positive, suggesting an important role of EBV in promoting lineage ambiguity/infidelity, whereas, all three cases in our series are negative for the virus. All three cases in our series show homogeneous expression of multiple B cell specific antigens, while the reported cases show variable expression with some having B cell antigens downregulated, particularly in those cases with EBV association or anaplastic morphology. A low threshold for testing EBV status is advocated in DLBCL with phenotypic ambiguity along with panels of immunohistochemical stains and B/T cell receptor gene rearrangement analysis.

Epstein-Barr Virus-Positive Pyothorax-Associated Lymphoma Arising from a Posttraumatic Empyema

Pyothorax-associated lymphoma (PAL) develops from a pyothorax caused by an artificial pneumothorax created during the treatment of pulmonary tuberculosis or tuberculous pleuritis. We report the first case of Epstein-Barr virus (EBV)-positive PAL arising from a posttraumatic empyema. A 75-year-old woman with chronic posttraumatic empyema presented with a tumor, which was connected to the wall of a pyothorax in the right thoracic cavity. She had a history of trauma to the right chest, which had occurred at the age of 45 years and had caused the chronic posttraumatic empyema. Pathological features of the resected tumor were conclusive for a diagnosis of EBV-positive PAL. Although neither postoperative chemotherapy nor radiotherapy was performed, remission was maintained for 3 years until recurrence in the liver. Combination chemotherapy led to complete remission, and 9 years after the initial diagnosis of PAL, the patient is still alive. An intriguing finding is the phenotypic alteration during the disease course. Although the primary tumor was negative for CD20 and CD3, the recurrent tumor expressed both of these molecules. We discuss this case of PAL, which was not a complication of lung tuberculosis, and the aberrant chronological phenotypic change observed in the lymphoma cells, and compare it with a usual case of PAL.

Incidence and clinical significance of aberrant T-cell marker expression on diffuse large B-cell lymphoma cells

INTRODUCTION

Aberrant expression of T-cell markers is occasionally observed in B-cell lymphomas. We conducted a retrospective study to establish its incidence and to determine its relationship with clinical features of patients with diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

We reviewed DLBCL patients diagnosed between January 2002 and April 2009. Patients fulfilled the following criteria: (1) age >18 years, (2) HIV negative, (3) B-cell lymphoma confirmed by restricted expression of surface immunoglobulin light chains by flow cytometry (FCM). Aberrant T-cell marker expression (ATCME) was defined as positivity for CD2, CD3, CD4, CD7, and/or CD8 on DLBCL cells by FCM. Phenotyping was also performed by immunohistochemistry (IHC). Patients were grouped according to positive or negative ATCME and their clinical features including survival were compared.

RESULTS

Of 150 patients, 11 (7.3%) showed ATCME; CD2 and CD7 were most often expressed. ATCME was less often detected and the signal was weaker using IHC. There were no statistically significant differences in clinical features between the two groups.

CONCLUSIONS

FCM may be useful to detect ATCME in a small amount of lymphoma cells. The mechanism responsible for ATCME, and whether it contributes in any way to the pathogenesis of B-cell neoplastic transformation, requires clarification.

A Unique "Composite" PTLD with Diffuse Large B-Cell and T/Anaplastic Large Cell Lymphoma Components Occurring 17 Years after Transplant

Posttransplant lymphoproliferative disorder (PTLD) comprises a spectrum ranging from polyclonal hyperplasia to aggressive monoclonal lymphomas. The majority of PTLDs are of B-cell origin while T-cell PTLDs and Hodgkin lymphoma-like PTLDs are uncommon. Here, we report a unique case of a 56-year-old man in whom a lymphoma with two distinct components developed as a duodenal mass seventeen years following a combined kidney-pancreas transplant. This PTLD, which has features not previously reported in the literature, consisted of one component of CD20 positive and EBV negative monomorphic diffuse large B-cell lymphoma. The other component showed anaplastic morphology, expressed some but not all T-cell markers, failed to express most B-cell markers except for PAX5, and was diffusely EBV positive. Possible etiologies for this peculiar constellation of findings are discussed and the literature reviewed for “composite-like” lymphomas late in the posttransplant setting.

Primary mediastinal (thymic) large B cell lymphoma with aberrant expression of CD3: a case report with review of the literature

We report the first case of primary mediastinal large B cell lymphoma (PMBL) with aberrant expression of CD3. PMBL is a subtype of diffuse large B cell lymphoma (DLBCL) and usually presents with bulky mediastinal lesions. Lineage ambiguity/infidelity is uncommon in DLBCL but has been described in sporadic case reports/series. A literature search identifies 13 additional cases of DLBCL expressing CD3, with the majority displaying cytoplasmic expression. Of the 14 total cases, 6 are pyothorax-associated lymphoma, 4 are conventional DLBCL, 2 are plasmablastic lymphoma, one is primary effusion lymphoma and one is PMBL. Two cases show genotypic ambiguity/infidelity with dual clonal IG and TCR gene rearrangements in addition to ambiguous immunophenotypes. Of the 13 cases tested for EBV status, 11 are positive, suggesting an important role of EBV in promoting lineage ambiguity/infidelity. A low threshold for testing EBV status is advocated in DLBCL with phenotypic ambiguity along with panels of immunohistochemical and molecular studies.

[Primary pleural lymphoma: a late complication of pleural decortication for tuberculosis: two cases in western countries]

Pleural lymphomas after a long standing pyothorax due to pleuropulmonary tuberculosis are now well identified, but rarely observed in Europe. We report two new cases in a non-immunocompromised patients. The two cases occurred 5455 years following artificial pneumothorax for pulmonary tuberculosis. The patients presented with a localized pleural tumor mass. Histology revealed high-grade lymphomas, diffuse large B-cell lymphoma and anaplastic lymphoma. Serology for Epstein-Barr virus was positive. Pleural lymphomas are an established complication of artificial pneumothorax. Epstein-Barr virus is known to play a crucial role in the pathogenesis, but despite the large number of artificial pneumothorax operations, these lymphomas remain rare, suggesting additional oncogenic factors.

Pyothorax-associated lymphoma: a case showing transition from T-cell-rich polymorphic lesion to diffuse large B-cell lymphoma

Pyothorax-associated lymphoma was found in a man who had a history of collapse therapy for pulmonary tuberculosis about 50 years ago. An autopsy specimen revealed histology of diffuse large B-cell lymphoma with latency III Epstein-Barr virus (EBV) infection. However, an open biopsy 2 years and 7 months before death showed a polymorphic appearance with abundant T-lymphocytes. Most of the EBV-infected atypical lymphocytes did not express either B- or T-cell markers as far as examined in the paraffin-embedded biopsy specimen, and rearrangements of immunoglobulin and T-cell receptors were not found. It seemed difficult to diagnose a B-cell lymphoma at the time of biopsy. However, retrospectively considered, if a phenotype of EBV-infected atypical lymphocytes is uncertain in cases showing polymorphic appearance, it might be better to consider the future evolution to overt B-cell lymphoma. Since pyothorax-associated lymphoma shows latency III infection of EBV, at least the immunohistochemistry of EBNA-2 and LMP-1 seems helpful for the diagnosis to prove which cells are infected by EBV.

Clinicopathological features of pyothorax-associated lymphoma; a retrospective survey involving 98 patients

To investigate clinicopathological features of pyothorax-associated lymphoma (PAL), we examined medical records of 98 patients (88 males and 10 females) with PAL at a median age of 70 years (range 51-86). Seventy-nine patients had a history of artificial pneumothorax. Median interval between diagnosis and artificial pneumothorax was 43 years (range 19-64). At diagnosis, performance status (PS) was 0-1 (n=56) and 2-4 (n=42). Clinical stages were I (n=42), II (n=26), III (n=8) and IV (n=22). Pathological diagnosis comprised diffuse large-B-cell (n=78) and peripheral T-cell lymphoma (n=1). Seventeen were treated supportively. The other 81 received aggressive treatments; chemotherapy (n=52), radiotherapy (n=7), surgery (n=4) and combination (n=18). Five-year overall survival (OS) was 0.35 (95% confidence interval, 24% to 45%). Causes of deaths were PAL (n=39), respiratory failure (n=13) and others (n=12). Multivariate analysis identified prognostic factors for OS; lactate dehydrogenase levels [hazard ratio (HR)=2.36; P=0.013], sex (female versus male) (HR=0.15; P=0.01), PS (2-4 versus 0-1) (HR=2.20; P=0.02), clinical stages (III/IV versus I/II) (HR=1.95; P=0.037) and chemotherapy (HR=0.31; P=0.01). Most patients with PAL are elderly and have comorbidities, while some of them achieve durable remission with appropriate treatments. These findings prompt us to establish an optimal treatment strategy on the basis of risk stratification of individual patients.

A 62-year-old man with chronic pyothorax

June 2005. Pyothorax-associated lymphoma (PAL) is a rare B-cell non-Hodgkin lymphoma (B-NHL) which develops in the pleural cavity after a 20- to 64-year history of chronic pyothorax. We present here the case of a 62-year-old man who suffered from chronic pyothorax after pneumectomy 44 years ago, and complained of progressive ataxia. A MRI of the head revealed a solitary lesion in the vermis cerebelli, and a biopsy showed a lymphoma displaying immunoblastic features. Immunohistochemistry revealed an aberrant dual B/T phenotype and an Epstein-Barr virus (EBV) type III LMP-1+/EBNA-2+ latency profile. In-situ hybridization disclosed EBV-encoded RNAs in the tumor cells. PCR for the detection of rearranged immunoglobulin heavy chain (IgH) genes followed by GeneScan analysis demonstrated a clonal B-cell population with DNA amplificates of identical size in the brain manifestation, and a large mediastinal tumor analyzed post mortem. Among the largest series of 106 PALs collected through a nationwide survey in Japan, central nervous system (CNS) involvement was detected in 5 (14%) of 36 patients where an autopsy had been performed. To best of our knowledge, this is the first case of a pyothorax-associated lymphoma initially diagnosed on brain biopsy.

Pyothorax-associated lymphoma: a lymphoma developing in chronic inflammation

Pyothorax-associated lymphoma (PAL) is a non-Hodgkin lymphoma of exclusively B-cell phenotype developing in the pleural cavity of patients after more than 20-year history of pyothorax resulting from an artificial pneumothorax for the treatment of pulmonary tuberculosis or tuberculous pleuritis. The most common symptoms on admission are chest pain and fever. Serum neuron-specific enolase level suggesting a diagnosis of small cell lung cancer is occasionally elevated. Histologically PAL usually shows a diffuse proliferation of large cells of B-cell type (diffuse large B-cell lymphoma [DLBL]). In PAL cells, representative B-cell markers other than CD20 are frequently negative with aberrant expression of T-cell markers such as CD2. A gene expression profile of PAL is distinct from nodal DLBL in its higher expression level of interferon-inducible genes. PAL is strongly associated with Epstein-Barr virus (EBV) infection with expression of EBV latent genes such as EBNA-2, LMP-1, together with EBNA-1. Taken together, PAL is a distinct entity both in its clinicopathologic presentation as well as its gene expression profile. Use of an artificial pneumothorax, EBV infection, and cytokines and reactive oxygen species produced in longstanding pyothorax might be important factors for PAL development.

CD20-negative pyothorax-associated B cell lymphoma

We describe an 86-year-old male who developed CD20-negative pyothorax-associated B cell lymphoma 64 years after he had suffered from tuberculous pleuritis. Therapy with 8 courses of THP-COP at 2-week intervals was followed by involved-field radiotherapy of 30 Gy. Uncertain complete remission was achieved. Thereafter, local recurrence of pyothorax-associated lymphoma (PAL) at the primary site was seen. The patient received salvage radiotherapy of 50 Gy. The patient died of pneumonia during a second uncertain complete remission. The progression-free survival and overall survival of this patient were 10 and 15 months, respectively. When compared with the median survival of 9 months reported in the literature, the adverse effect of CD20 negativity on prognosis may not apply to PAL patients with an occasional aberrant phenotype.

Pyothorax-associated lymphoma (PAL): a western case with marked angiocentricity and review of the literature

AIMS

To report a case of pyothorax-associated lymphoma in a non-immunocompromised 78-year-old man with a 45-year history of tuberculous pleuritis and left pleural effusion. Pyothorax-associated lymphoma is a high-grade non-Hodgkin's lymphoma occurring in 2% of patients with long-standing tuberculous pleuritis and pyothorax. Pyothorax-associated lymphoma is frequently Epstein-Barr virus (EBV)-associated, mainly reported in Japan but exceedingly rare in western countries.

METHODS AND RESULTS

Histology revealed a high-grade, diffuse large B-cell lymphoma with immunoblastic and plasmacytoid features and marked angiocentricity with focal destruction of the vessel walls. Immunohistochemistry revealed a post germinal B-cell phenotype. RNA in-situ hybridization and molecular analysis showed a latent EBV infection and absence of human herpes virus-8 (HHV-8).

CONCLUSIONS

Pyothorax-associated lymphoma represents a rare but distinctive type of diffuse large B-cell lymphoma, with characteristic clinico-epidemiological, immunohistological, and biological features.

B-cell marker negative (CD7+, CD19-) Epstein-Barr virus-related pyothorax-associated lymphoma with rearrangement in the JH gene

Pyothorax-associated lymphoma (PAL) develops decades after receiving artificial pneumothorax for pulmonary tuberculosis. The lymphomas, develop in tissue affected by long-standing severe inflammatory process. Most cases demonstrate diffuse large B-cell lymphoma. We present a patient with T-cell phenotype-positive and B-cell phenotype-negative (CD7+, CD43+, CD19-, and CD20-) PAL. Southern blot hybridization using immunglobulin heavy chain J region (IgH) gene probe revealed a monoclonal rearrangement, and hybridization using T-cell receptor beta chain (TCR) gene probe revealed a germline configuration. This indicates that the tumor origin was of B-lymphocytes. Chromosomal abnormality of the lymphoma was complicated. It suggested that many transformations occurred. In the transformation process, probably B-cell antigens were lost, and T-cell antigens were aberrantly expressed.

Pyothorax-associated lymphoma: a peculiar clinicopathologic entity derived from B cells at late stage of differentiation and with occasional aberrant dual B- and T-cell phenotype

We report 12 European cases of pyothorax-associated lymphomas occurring 30-67 years following artificial pneumothorax for pleuropulmonar tuberculosis. Eleven patients presented with a localized pleural tumor mass, whereas one patient also had liver involvement. Histologic examination showed a diffuse proliferation of large lymphoid cells with frequent plasmacytoid differentiation (n = 8), expressing CD20 (n = 10), CD79a (n = 11), and/or CD138 (n = 5) B-cell antigens. Aberrant expression of T-cell markers (CD2, CD3, CD4) was noted in five cases. The B-cell origin of lymphoma cells was confirmed by the demonstration of immunoglobulin light chain restriction or clonal B cell population in six cases. In 11 of 12 cases in situ hybridization disclosed Epstein-Barr virus genome in most tumor cells and immunohistochemistry a type III LMP-1+/ EBNA-2+ latency profile. HHV-8/ORF73 antigen was not detected in all tested cases (n = 11). All investigated cases (10 of 10) disclosed a uniform CD10-/BCL-6-/MUM1+/CD138+/- phenotype, consistent with a derivation from late germinal center (GC)/post-GC B cells. Clinical outcome was poor with a median survival time of 5 months. Only one patient was in complete remission after 34 months. This study further confirms that pyothorax-associated lymphoma represents a distinct clinicopathologic entity among diffuse large B-cell lymphoma, which is characterized by a peculiar clinical presentation, frequent plasmacytoid features, and a strong association with EBV. Moreover, we show that this lymphoma entity likely originates from B cells at a late stage of differentiation and occasionally shares an aberrant dual B/T phenotype.

Expression profile of human herpesvirus 8 (HHV-8) in pyothorax associated lymphoma and in effusion lymphoma

AIMS

Pyothorax associated lymphoma (PAL) occurs in a clinical setting of longstanding pyothorax or chronic inflammation of the pleura. Like primary effusion lymphoma, it has an association with Epstein-Barr virus (EBV), and is confined to the pleural cavity, but has differing morphological and phenotypic features. Human herpesvirus 8 (HHV-8) has been consistently reported in primary effusion lymphoma. This study examines the immunophenotype of two European cases of PAL, investigates the presence of HHV-8 and its expression profile, and assesses whether PAL is similar to other effusion lymphomas.

METHODS

Material was obtained from two European cases of PAL. Immunocytochemical analysis was performed using antibodies against CD45, CD20, CD79a, CD45RAA, CD3, CD43, CD45RO (UCHL1), CD30, BCL-2, CD68, epithelial membrane antigen (EMA), BCL-6, p53, Ki-67, kappa light chain, lambda light chain, and the EBV antigens latent membrane protein 1 (LMP-1) and EBV encoded nuclear antigen 2 (EBNA-2). The cases were examined for HHV-8 by means of polymerase chain reaction in situ hybridisation (PCR-ISH), solution phase PCR, in situ hybridisation (ISH), and real time quantitative TaqMan PCR to HHV-8 open reading frame 26 (ORF-26) and viral (v) cyclin encoding regions. The expression profile of HHV-8 in PAL and in BC-1 and BC-3 cells was assessed by RNA TaqMan PCR to the HHV-8 genes encoding v-cyclin, v-IL-6, and G protein coupled receptor (GPCR).

RESULTS

Both cases expressed CD24, CD20, CD79a, BCL-2, light chain restriction, and high Ki-67 staining. EBV was identified by EBER-ISH in one case. HHV-8 was not identified by solution phase PCR, but was detected by PCR-ISH (sensitivity of 1 viral genome copy/cell) in 35% of the cells and by TaqMan PCR, which showed 50-100 HHV-8 copies/2,000 cell genome equivalents (sensitivity of 1 viral genome in 10(6) contaminating sequences). HHV-8 v-IL-6, v-cyclin, and GPCR encoded transcripts were identified using RNA TaqMan PCR. v-IL-6 was high in PAL and in BC-1 and BC-3 cells.

CONCLUSION

The presence of HHV-8 in one of two patients with PAL raises interesting questions in relation to the pathobiology of the condition. Clearly, the results indicate that HHV-8 is not an obligate pathogen, necessary for the effusion phenotype, but might contribute to it by its secretion of specific cytokines.

Herpesvirus 8 inclusions in primary effusion lymphoma: report of a unique case with T-cell phenotype

We describe a case of primary effusion lymphoma with T-cell phenotype, mixed genotype, and intranuclear herpesvirus inclusions visible with the light microscope. Cells were studied by immunohistochemical analysis, in situ hybridization, immunoglobulin and T-cell receptor gene rearrangement, and polymerase chain reaction. Primary effusion lymphoma cells with T-cell phenotype revealed herpesvirus 8 inclusions predominantly seen in apoptotic cells, suggesting that productive viral infection is associated with cell death. Clinical features were typical of primary effusion lymphoma. Cytologic, molecular genetic, and phenotypic features demonstrated a unique variant of primary effusion lymphoma.

Mechanism for the development of pyothorax-associated lymphoma

Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. Thus, the term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most PAL are of the type diffuse lymphoma of B cell and contain Epstein-Barr virus (EBV) DNA. This article reviews the mechanism for the development of PAL. The possible contribution of EBV infection, inflammatory cytokines and other genetic lesions, including the p53 gene, towards the growth advantage of neoplastic cells is described. Although the presence of EBV is focused in PAL cells, the contribution of EBV-mediated growth promotion in PAL is limited. Another important characteristic of PAL is that the virus antigen-positive lymphoma develops in patients with pyothorax, in whom the systemic immunodeficiency is unlikely to be present. Therefore, in the course of the development of PAL, the mechanism for the evading host immune surveillance must be obvious. In this context, the production of an immunosuppressive cytokine from PAL cells, human histocompatibility leukocyte antigen class I alleles of patients with PAL, and the mutations of cytotoxic T lymphocyte epitopes in an EBV-latent antigen are described. These mechanisms could be involved in the development of PAL, an EBV-positive lymphoma developing in an immunocompetent host, and also shed light on the tumorigenesis of other EBV-positive neoplasms and on the lymphomagenesis of other inflammatory lesions.

Pyothorax-associated lymphoma: description of the first two cases detected in Italy

BACKGROUND

Pyothorax-associated lymphoma (PAL) is a rare, but distinct, clinico-pathologic entity which occurs most often in Japanese people; to the best of our knowledge, only six cases of it have been reported in Western countries. The tumour develops several decades following artificial pneumothorax or chronic pleuritis due to tuberculous infection, produces pleural effusion associated with extensive local lymphomatous infiltrates, and is sustained by a polymorphic large B-cell clonal proliferation showing EBV integration in the genoma of the neoplastic cells.

PATIENTS AND METHODS

Herein we describe two cases of PAL observed in Italian patients, both extensively studied on the clinical, pathological, phenotypic, virological, and molecular levels.

RESULTS

The two cases occurred, respectively, 45 and 50 years after therapeutic pneumothorax because of tuberculous pleuritis and were characterized by a pleural mass extending to the thoracic wall, which on histological examination were seen to consist of large elements with immunoblastic morphology. Immunohistochemistry show monotypic restriction of Ig light chains, as well as the expression of CD45, B-cell markers (CD20, CD79a, CD45RA), bcl-2 oncogene product, EBNA-2 and, partially, LMP-1. The ratio of cycling cells was extremely high as was the number of mitotic figures. In situ hybridization displayed the presence in the neoplastic cells of the EBV-related small RNAs EBER 1 and 2, which in turn, along with the positivity for EBNA-2 and LMP-1, further strengthened the close relationships between PAL and latent viral infection. Molecular studies revealed, on one hand, clonal rearrangement of the Ig heavy chain J region genes, and on the other, negativity for HHV8 in one case and positivity in the other.

CONCLUSIONS

These cases of PAL are the first to be documented in Italy; they serve to direct attention to the fact that this condition is not confined to Japanese people, and that its occurrence in Western countries might be underestimated.