The morphologic and molecular genetic categories of posttransplantation lymphoproliferative disorders are clinically relevant

Immune deficiency/dysregulation -associated lymphoproliferative disorders. Revised classification and management

Significant advances in the field of lymphoma have resulted in two recent classification proposals, the International Consensus Classification (ICC) and the 5th edition WHO. A few entities are categorized differently in the ICC compared to the WHO. Nowhere is this more apparent than the immunodeficiency lymphoproliferative disorders. The three previous versions of the WHO classification (3rd, 4th and revised 4th editions) and the ICC focused on four clinical settings in which these lesions arise for primary categorization. In contrast the 2023 WHO 5th edition includes pathologic characteristics including morphology and viral status, in addition to clinical setting, as important information for lesion classification. In addition, the 2023 WHO recognizes a broader number of clinical scenarios in which these lesions arise, including not only traditional types of immune deficiency but also immune dysregulation. With this classification it is hoped that new treatment strategies will be developed leading to better patient outcomes.

The pathobiology of select adolescent young adult lymphomas

Lymphoid cancers are among the most frequent cancers diagnosed in adolescents and young adults (AYA), ranging from approximately 30%-35% of cancer diagnoses in adolescent patients (age 10-19) to approximately 10% in patients aged 30-39 years. Moreover, the specific distribution of lymphoid cancer types varies by age with substantial shifts in the subtype distributions between pediatric, AYA, adult, and older adult patients. Currently, biology studies specific to AYA lymphomas are rare and therefore insight into age-related pathogenesis is incomplete. This review focuses on the paradigmatic epidemiology and pathogenesis of select lymphomas, occurring in the AYA patient population. With the example of posttransplant lymphoproliferative disorders, nodular lymphocyte-predominant Hodgkin lymphoma, follicular lymphoma (incl. pediatric-type follicular lymphoma), and mediastinal lymphomas (incl. classic Hodgkin lymphoma, primary mediastinal large B cell lymphoma and mediastinal gray zone lymphoma), we here illustrate the current state-of-the-art in lymphoma classification, recent molecular insights including genomics, and translational opportunities. To improve outcome and quality of life, international collaboration in consortia dedicated to AYA lymphoma is needed to overcome challenges related to siloed biospecimens and data collections as well as to develop studies designed specifically for this unique population.

Post-transplant lymphoproliferative disorders (PTLD) in adolescents and young adults: A category in need of definition

Post-transplant lymphoproliferative disorders are a well-recognized complication of solid organ and stem cell transplantation. Much data has accumulated with respect to the pathobiology and clinical behavior of these lesions in the general post-transplant population as well as in the pediatric and adult age groups. However, information as to these lesions in the adolescent and young adult populations, which bridge the pediatric and adult groups, is limited. In this review, the focus is on this unique population of PTLD patients and their proliferations.

KSHV/HHV8-mediated hematologic diseases

Kaposi sarcoma (KS) herpesvirus (KSHV), also known as human herpesvirus 8, is the causal agent of KS but is also pathogenetically related to several lymphoproliferative disorders, including primary effusion lymphoma (PEL)/extracavitary (EC) PEL, KSHV-associated multicentric Castleman disease (MCD), KSHV+ diffuse large B-cell lymphoma, and germinotropic lymphoproliferative disorder. These different KSHV-associated diseases may co-occur and may have overlapping features. KSHV, similar to Epstein-Barr virus (EBV), is a lymphotropic gammaherpesvirus that is preferentially present in abnormal lymphoid proliferations occurring in immunecompromised individuals. Notably, both KSHV and EBV can infect and transform the same B cell, which is frequently seen in KSHV+ EBV+ PEL/EC-PEL. The mechanisms by which KSHV leads to lymphoproliferative disorders is thought to be related to the expression of a few transforming viral genes that can affect cellular proliferation and survival. There are critical differences between KSHV-MCD and PEL/EC-PEL, the 2 most common KSHV-associated lymphoid proliferations, including viral associations, patterns of viral gene expression, and cellular differentiation stage reflected by the phenotype and genotype of the infected abnormal B cells. Advances in treatment have improved outcomes, but mortality rates remain high. Our deepening understanding of KSHV biology, clinical features of KSHV-associated diseases, and newer clinical interventions should lead to improved and increasingly targeted therapeutic interventions.

The Tumor Microenvironment in Post-Transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLDs) cover a broad spectrum of lymphoproliferative lesions arising after solid organ or allogeneic hematopoietic stem cell transplantation. The composition and function of the tumor microenvironment (TME), consisting of all non-malignant constituents of a tumor, is greatly impacted in PTLD through a complex interplay between 4 factors: 1) the graft organ causes immune stimulation through chronic antigen presentation; 2) the therapy to prevent organ rejection interferes with the immune system; 3) the oncogenic Epstein-Barr virus (EBV), present in 80% of PTLDs, has a causative role in the oncogenic transformation of lymphocytes and influences immune responses; 4) interaction with the donor-derived immune cells accompanying the graft. These factors make PTLDs an interesting model to look at cancer-microenvironment interactions and current findings can be of interest for other malignancies including solid tumors. Here we will review the current knowledge of the TME composition in PTLD with a focus on the different factors involved in PTLD development.

Epstein-Barr Virus-Positive Extranodal Marginal Zone Lymphoma of Bronchial-Associated Lymphoid Tissue in the Posttransplant Setting: An Immunodeficiency-Related (Posttransplant) Lymphoproliferative Disorder?

OBJECTIVES

Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of hematolymphoid proliferations arising in the context of chronic immunosuppression. The common and indolent B-cell lymphomas, including extranodal marginal zone lymphomas (ENMZLs) of mucosa-associated lymphoid tissue (MALT), are excluded from the category of PTLD in the current World Health Organization classification.

METHODS

We report a case of Epstein-Barr virus (EBV)-positive bronchial-associated lymphoid tissue (BALT) lymphoma involving the lungs of a transplant patient.

RESULTS

Aside from history of cardiac transplant, young patient age, and EBV positivity, the histopathologic findings were indistinguishable from usual BALT lymphoma.

CONCLUSIONS

We review the literature of ENMZL occurring in immunocompromised patients and present this case for consideration that this specific entity is a PTLD. We believe that additional studies might lend strength to the hypothesis that this particular group of EBV-positive, posttransplant ENMZLs merits classification and management as PTLDs.

A suspected case of plasma cell-rich acute renal transplant rejection associated with de novo donor-specific antibody

A kidney transplant case with de novo donor-specific antibody showed monoclonal plasma cell infiltration into the graft with ABO incompatibility. Three years after transplantation, the patient's graft function suddenly deteriorated. Interstitial edema and the predominant infiltration of inflammatory plasma cells with kappa chain monoclonality were observed in biopsy specimens. The in situ hybridization of Epstein-Barr virus was negative and post-transplant lymphoproliferative disorder was not evident from radiological examinations. On laboratory examination, the patient had de novo donor-specific antibody for HLA-DQ. We suspected plasma cell-rich acute rejection for which methylprednisolone pulse therapy, plasma exchange, rituximab, and 15-deoxyspergualin were given. In the ensuing biopsy, the degree of plasma cell infiltration was similar to the first biopsy; however, kappa chain monoclonality relatively weakened. Owing to resistance to these treatments, intravenous immunoglobulin (IVIG) (0.5 g/kg/day) was added. The serum creatinine level gradually declined to 3.1 mg/dL; however, it increased up to 3.6 mg/dL again. In the final biopsy, the infiltrated plasma cells disappeared but severe interstitial fibrosis developed. This case showed difficulty in the diagnosis and treatment of plasma cell-rich acute rejection. A detailed consideration of this case may be helpful in understanding the clinical features and pathogenesis of this condition.

Lymphoproliferative neoplasms of the lung: a review

CONTEXT

Diagnosis and classification of lymphomas are based on the morphologic, immunologic, and genetic features that the lesional cells share with their normal B and T lymphocyte counterparts. Primary pulmonary lymphomas account for 0.3% of primary lung neoplasms and less than 0.5% of all lymphomas.

OBJECTIVE

To describe and summarize the clinical and histopathologic features of the primary pulmonary lymphoma and secondary involvement of the lung by lymphoma.

DATA SOURCES

Peer-reviewed published literature and personal experience.

CONCLUSIONS

Diagnosis of clonal lymphoid proliferations in the lung has evolved owing to the greater utility of molecular and flow cytometric analysis of tissue. Further studies are needed to best define the clinical and prognostic features, as well as search for targeted therapy for these patients with rare neoplasms.

Early posttransplant lymphoproliferative disease: clinicopathologic features and correlation with mTOR signaling pathway activation

Early posttransplant lymphoproliferative disorders (EPTLDs) represent the first changes in posttransplant lymphoproliferative disorders (PTLDs) morphologic spectrum. EPTLD data are available mostly from case reports and series that include other types of PTLD. Fifteen EPTLDs were reviewed retrospectively. Clinical data, histopathology, clonality, and Epstein- Barr virus (EBV) status were correlated with staining intensity to an antibody for phosphorylated S6 (pS6) ribosomal protein, a downstream effector of mammalian target of rapamycin (mTOR). Median time from transplantation to EPTLD was 50 months (range, 7-135 mo). EPTLDs involved tonsil and/or adenoids (n = 11) and lymph nodes (n = 4), all of which were nonclonal and EBV-encoded RNA-positive. Most (n = 11) were plasmacytic hyperplasia and florid follicular hyperplasia (n = 4). All regressed with reduced immunosuppression, and had increased pS6 staining compared with normal tonsil (P = .002, F test). EPTLDs developed later than previously reported, involved mostly tonsils/adenoids, were EBV-encoded RNA (EBER) positive, showed increased pS6, and had excellent clinical outcome with reduction of immunosuppression.

Posttransplant lymphoproliferative disorders

Posttransplant lymphoproliferative disorders (PTLDs) are a group of diseases that range from benign polyclonal to malignant monoclonal lymphoid proliferations. They arise secondary to treatment with immunosuppressive drugs given to prevent transplant rejection. Three main pathologic subsets/stages of evolution are recognised: early, polymorphic, and monomorphic lesions. The pathogenesis of PTLDs seems to be multifactorial. Among possible infective aetiologies, the role of EBV has been studied in depth, and the virus is thought to play a central role in driving the proliferation of EBV-infected B cells that leads to subsequent development of the lymphoproliferative disorder. It is apparent, however, that EBV is not solely responsible for the “neoplastic” state. Accumulated genetic alterations of oncogenes and tumour suppressor genes (deletions, mutations, rearrangements, and amplifications) and epigenetic changes (aberrant hypermethylation) that involve tumour suppressor genes are integral to the pathogenesis. Antigenic stimulation also plays an evident role in the pathogenesis of PTLDs. Plasmacytoid dendritic cells (PDCs) that are critical to fight viral infections have been thought to play a pathogenetically relevant role in PTLDs. Furthermore, regulatory T cells (Treg cells), which are modulators of immune reactions once incited, seem to have an important role in PTLDs where antigenic stimulation is key for the pathogenesis.

[Hematologic malignant complications after transplantation]

Post-transplant hemopathies are a serious complication of organ transplantation. They include several entities: non-hodgkin lymphoma, Hodgkin disease and myeloma. The pathophysiology, clinical and histological features, treatment and evolution of these diseases are different, but share some similarities. Among factors involved in lymphomagenesis, the role of Epstein Barr virus and immunosuppression are central. EBV primo-infection or reactivation together with a deep depression of T-cell immunity is at particular risk of lymphoma development. The clinical expression and outcome of lymphomas are varied. Assays for EBV replication quantification have been developed leading to immunosuppression decreasing and antiviral therapy when the replication increases. Treatment of post-transplant lymphoproliferations consists mainly in immunotherapy and chemotherapy. Hodgkin disease and myeloma are rare after transplantation; their management is close to the one of immunocompetent patients. The recurrence of myeloma, amyloidosis or light chain deposition disease seems frequent after transplantation and only patients with disappearance of monoclonal component should be proposed for transplantation. On the opposite, the risk of recurrence appears lower for Hodgkin disease; therefore the transplantation of patients with a history of Hodgkin disease looks possible.

Long-term monitoring of Epstein-Barr virus DNA load and humoral parameter abnormalities in pediatric liver transplant recipients before development of malignancy

EBV loads and abnormalities of humoral responses were monitored in 51 pediatric liver transplant recipients as a proposed non-invasive laboratory tool for early detection of changes preceding severe clinical complications. EBV DNA load, concentrations of IgM, IgG, IgA, and monoclonal proteins were determined in each blood sample. EBV DNA was detected in 70.6% of the children, dysgammaglobulinemia of one or more Ig isotype was present in 41.2% of them. MG detected in 43.1% of patients correlated with the presence of EBV DNA (p = 0.003) and was usually preceded by hypergammaglobulinemia. The median maximum EBV load was significantly higher in EBV DNA+/MG+ patients than in EBV DNA+/MG- patients (p = 0.04), although there was no correlation between current viral load and appearance of MG. Four of 15 EBV DNA-negative patients developed MG, preceded by hypergammaglobulinemia in two. Minimization or cessation of immunosuppression in 42 patients, in whom abnormal biomarkers and/or clinical symptoms raised suspicion of disease progression, permitted complete resolution of abnormalities in all but one patient who developed B-NHL and died. Simultaneous monitoring of protein profiles and EBV DNA load together with thorough physical evaluation of children after LTx is important for early implementation of suitable preemptive therapy.

Using Epstein-Barr viral load assays to diagnose, monitor, and prevent posttransplant lymphoproliferative disorder

Epstein-Barr virus (EBV) DNA measurement is being incorporated into routine medical practice to help diagnose, monitor, and predict posttransplant lymphoproliferative disorder (PTLD) in immunocompromised graft recipients. PTLD is an aggressive neoplasm that almost always harbors EBV DNA within the neoplastic lymphocytes, and it is often fatal if not recognized and treated promptly. Validated protocols, commercial reagents, and automated instruments facilitate implementation of EBV load assays by real-time PCR. When applied to either whole blood or plasma, EBV DNA levels reflect clinical status with respect to EBV-related neoplasia. While many healthy transplant recipients have low viral loads, high EBV loads are strongly associated with current or impending PTLD. Complementary laboratory assays as well as histopathologic examination of lesional tissue help in interpreting modest elevations in viral load. Circulating EBV levels in serial samples reflect changes in tumor burden and represent an effective, noninvasive tool for monitoring the efficacy of therapy. In high-risk patients, serial testing permits early clinical intervention to prevent progression toward frank PTLD. Restoring T cell immunity against EBV is a major strategy for overcoming PTLD, and novel EBV-directed therapies are being explored to thwart virus-driven neoplasia.

Posttransplant lymphoproliferative diseases

The risk of developing cancer after solid organ transplantation (SOT) is about 5- to 10-fold greater than that of the general population. The cumulative risk of cancer rises to more than 50% at 20 years after transplant and increases with age, and so children receiving transplants are at high risk of developing a malignancy. Posttransplant lymphoproliferative disease (PTLD) is the most common cancer observed in children following SOT, accounting for half of all such malignancies. PTLD is a heterogeneous group of disorders with a wide spectrum of pathologic and clinical manifestations and is a major contributor to long-term morbidity and mortality in this population. Among children, most cases are associated with Epstein-Barr virus infection. This article reviews the pathology, immunobiology, epidemiology, and clinical aspects of PTLD, underscoring the need for ongoing systematic study of complex biologic and therapeutic questions.

Post-transplant lymphoproliferative disorder localized in the colon after liver transplantation: report of a case

Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication of any organ transplantation. It is more common in children than in adults, and the risk factors include Epstein-Barr virus (EBV) infection and immunosuppression. We report a case of colonic marginal zone B-cell lymphoma occurring 4 years after liver transplantation in a 52-year-old man who had been taking immunosuppressive agents, namely, cyclosporin, mycophenolate mofetil (MMF), and prednisolone. A routine follow-up colonoscopy showed a 2.0-cm diffuse nodular transverse colon polyp covered with erosive mucosa. Snare polypectomy was done without any complications. Immunohistochemical staining was positive for CD3 and CD20 in the interstitially scattered small lymphocytes and negative for Bcl-2, revealing marginal zone B-cell lymphoma. EBV quantitative polymerase chain reaction was less than the detection limit (<10 copies/5 microl whole blood). Extraintestinal whole-body screening was negative. The patient underwent right hemicolectomy after colonoscopic tattooing for positive resection margins on snare polypectomy. Surgical pathology revealed no evidence of residual lymphoma. Treatment consisted of colonic resection and reduction of the doses of immunosuppressants. The patient is currently under close surveillance without any signs of recurrence.

Cutaneous presentation of post-renal transplant lymphoproliferative disorder: a series of four cases

We report detailed histological and molecular characteristics of four post transplant lymphoproliferative disorders (PTLD) presenting in the skin of renal transplant patients, and their clinical outcome. Three had B-cell lymphomas (cases 1-3), and one had a T-cell lymphoma (case 4). All B-cell lymphomas showed Epstein-Barr virus (EBV) by immunohistochemistry (IHC) or in situ hybridization (ISH). Cases 1 and 2 were large cell lymphomas, and case 3 a plasmacytoma. Case 1 showed light chain restriction and heavy chain gene rearrangement by polymerase chain reaction (PCR). The patient was then diagnosed with an abdominal lymphoma and died of sepsis. Case 2 had no recoverable DNA. Case 3 had a plasmacytoma that showed monoclonal light chain restriction on IHC and an oligoclonal heavy chain rearrangement by PCR. In cases 2 and 3, the lesions regressed following reduction of immunosuppression, and died 1.5 and 8 years later from unrelated medical causes. Case 4 was a CD 30+ anaplastic large T-cell lymphoma with no EBV detected by IHC, ISH and PCR, and died of heart failure 2 years later. Cutaneous manifestations of PTLD are rare, show wide array of clinical and pathological features, and generally have a favorable prognosis. EBV appears to be associated only with B-cell cutaneous lymphomas.

Epstein-Barr virus positive diffuse large B-cell lymphoma of the elderly

Epstein-Barr virus positive diffuse large B-cell lymphoma (EBV+ DLBCL) of the elderly is a rare B-cell lymphoproliferative disorder (B-LPD) that occurs in patients > 50 years with no known history of immunodeficiency or lymphoma. Patients present with moderate to severe clinical B-symptoms. These lesions show complete effacement of normal tissue/nodal architecture by large atypical lymphoid cells/immunoblasts and Hodgkin/Reed-Sternberg-like giant cells with variable amounts of inflammatory cells in the background. The ratio of neoplastic to inflammatory cells, degree of mitoses and necrosis can be quite variable; hence EBV+ DLBCL of the elderly was historically divided into low grade polymorphic and high grade monomorphic types. Further studies have shown both types to be different points in the spectrum of disease, and are all high grade lymphomas. The neoplastic large lymphoid cells show expression of CD20/CD79a and PAX-5, with variable expression of CD30, LMP-1 and EBNA-2, but CD15, CD10 and BCL6 are generally negative. Neoplastic cells show EBER positivity and high Ki-67 expression. Differential diagnoses include EBV+ B-LPD, classical Hodgkin lymphoma and EBV-DLBCL. EBV+ DLBCL of the elderly is highly aggressive with a median survival of 2 years. These patients are less responsive to standard chemotherapy compared with other B-LPD.

Associations of serum EBV DNA and gammopathy with post-transplant lymphoproliferative disease

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is a life-threatening complication of immunosuppression following transplantation. Epstein-Barr virus (EBV) and gammopathy in serum are associated with PTLD, but these two parameters have not been evaluated in parallel for their association with PTLD.

METHODS

We evaluated the incidence of EBV load positivity, gammopathy, and protein expression in sera from all PTLD patients diagnosed at our hospital during the past seven yr. Results were compared with those of a control group including matched transplanted patients who did not develop PTLD.

RESULTS

Seven of 10 PTLD patients presented EBV(+) PTLD, for which five patients had detectable serum EBV DNA levels compared with none of 38 controls (RR between two groups =121, p < 0.0001). Five out of 10 patients had gammopathy at PTLD diagnosis compared with 5/38 controls (RR between two groups = 6.6, p = 0.022). Additionally, protein serum analysis by high-resolution two-dimensional gel electrophoresis and image examination failed to evidence specific abnormality in patients with PTLD compared with controls.

CONCLUSIONS

Our results confirm an association between EBV in sera and gammopathy with PTLD, and highlight the high specificity of the former analysis. Whether a combination of both analyses will improve the clinical detection of PTLD remains to be evaluated in a larger prospective cohort study.

Lung

Experiments with animals in the 1940 and 1950s demonstrated that lung transplantation was technically possible [33]. In 1963, Dr. James Hardy performed the first human lung transplantation. The recipient survived 18 days, ultimately succumbing to renal failure and malnutrition [58]. From 1963 through 1978, multiple attempts at lung transplantation failed because of rejection and complications at the bronchial anastomosis. In the 1980s, improvements in immunosuppression, especially the introduction of cyclosporin A, and enhanced surgical techniques led to renewed interest in organ transplantation. In 1981, a 45-year-old-woman received the first successful heart–lung transplantation for idiopathic pulmonary arterial hypertension (IPAH) [106]. She survived 5 years after the procedure. Two years later the first successful single lung transplantation for idiopathic pulmonary fibrosis (IPF) [128] was reported, and in 1986 the first double lung transplantation for emphysema [25] was performed.

EBV-associated lymphoproliferative disorders: classification and treatment

Since its discovery as the first human tumor virus, Epstein-Barr virus (EBV) has been implicated in the development of a wide range of B-cell lymphoproliferative disorders, including Burkitt's lymphoma, classic Hodgkin's lymphoma, and lymphomas arising in immunocompromised individuals (post-transplant and HIV-associated lymphoproliferative disorders). T-cell lymphoproliferative disorders that have been reported to be EBV associated include a subset of peripheral T-cell lymphomas, angioimmunoblastic T-cell lymphoma, extranodal nasal type natural killer/T-cell lymphoma, and other rare histotypes. EBV encodes a series of products interacting with or exhibiting homology to a wide variety of antiapoptotic molecules, cytokines, and signal transducers, hence promoting EBV infection, immortalization, and transformation. However, the exact mechanism by which EBV promotes oncogenesis is an area of active debate. The focus of this review is on the pathology, diagnosis, classification, and pathogenesis of EBV-associated lymphomas. Recent advances in EBV cell-based immunotherapy, which is beginning to show promise in the treatment of EBV-related disorders, are discussed.

BCL6 expression correlates with monomorphic histology in children with posttransplantation lymphoproliferative disease

Posttransplantation lymphoproliferative disease (PTLD) is a complication of organ transplantation with high mortality. Predicting response to first-line therapy, reduction of immune suppression, is difficult because of the heterogeneity of lesions and disease behavior. We sought to determine if BCL6 protein expression in PTLD cells is associated with poor outcome. In a cohort of 25 children with PTLD, 9 of the patients' tumor specimens were positive for BCL6 protein expression. Eight of 13 monomorphic lesions were BCL6 positive, compared with 1 of 11 evaluable polymorphic lesions (P=0.01). Only 1 of the patients with BCL6 expression responded to reduced immune suppression (P=0.19). Recipients of heart transplants who developed PTLD had reduced overall survival rates compared with recipients of other organ transplants who developed PTLD (P=0.04).

Rituximab for lymphoproliferative disease prior to haematopoietic stem cell transplantation for X-linked severe combined immunodeficiency

Lymphoproliferative disease (LPD) is a complication of congenital and acquired immunodeficiency states. There are a number of treatment options for LPD arising after haematopoietic stem cell or solid organ transplantation including reduction of immunosuppression, targeted therapies, such as the anti-CD20 monoclonal antibody, rituximab, and EBV specific cytotoxic lymphocytes. Treatment of LPD in children with congenital immunodeficiency syndromes remains unsatisfactory and is associated with a high mortality rate. We recently managed an infant found to have polymorphic LPD concurrent with X-linked severe combined immunodeficiency (SCID). Haematopoietic stem cell transplantation (HSCT) had to be deferred because of progressive LPD. Treatment with rituximab resulted in regression of the LPD following which the patient received a 5/6 HLA matched umbilical cord blood (UCB) transplant. The patient remains well 20 months following transplantation. Rituximab treatment may have a useful role in the control of LPD associated with congenital immunodeficiency prior to HSCT.

The clinicopathologic spectrum of posttransplantation lymphoproliferative disorders

CONTEXT

Posttransplantation lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations occurring in the setting of solid organ or bone marrow transplantation. They show a clinical, morphologic, and molecular genetic spectrum ranging from reactive polyclonal lesions to frank lymphomas. The close association with Epstein-Barr virus has been established and the pathogenetic role of this virus is becoming better understood. Although they are relatively uncommon, PTLDs are a significant cause of morbidity and mortality in transplant patients.

OBJECTIVE

To review the incidence, risk factors, clinical features, pathogenesis, and classification of PTLDs.

DATA SOURCES

We reviewed relevant articles indexed in PubMed (National Library of Medicine), with emphasis on more recent studies. The classification of PTLDs is based on the most current World Health Organization classification text.

CONCLUSIONS

Posttransplantation lymphoproliferative disorders are a heterogeneous group of disorders showing a wide clinical and morphologic spectrum. Although relatively uncommon, PTLDs represent a serious complication after transplantation. Many risk factors for PTLD are well established, including transplanted organ, age at transplant, and Epstein-Barr virus seronegativity at transplant. However, other factors have been implicated and still require additional examination. Recent studies are shedding some light on the pathogenesis of PTLDs and defining relevant pathways related to Epstein-Barr virus. As the pathogenesis of PTLDs is further elucidated, the classification of PTLDs will most likely evolve.

Immunodeficiency-related Hodgkin lymphoma and its mimics

Classic Hodgkin lymphoma (CHL) in patients with underlying immunodeficiency disorders frequently differs from that in the immune competent population in terms of its clinical behavior and pathologic features. Moreover, differential from Hodgkin-like lymphoid proliferations may be problematic. Topics under review include: (a) CHL posttransplant lymphoproliferative disorders, (b) CHL in HIV/AIDS, (c) Hodgkin variant of Richter syndrome in chronic lymphocytic leukemia in association with fludarabine therapy, (d) CHL in other immunodeficiency states including methotrexate-associated lymphoproliferative disorder in patients with rheumatoid arthritis and primary immune deficiencies, and (e) Hodgkin-like lymphoid proliferations including senile Epstein-Barr virus+ B-cell lymphoproliferative disorder. Also under consideration is the pathogenesis of these disorders with an emphasis on the role of Epstein-Barr virus.

B-cell posttransplant lymphoproliferative disorders in heart and/or lungs recipients: clinical and molecular-histogenetic study of 17 cases from a single institution

BACKGROUND

Posttransplantation lymphoproliferative disorders (PTLDs) are heterogeneous lymphoid proliferations representing a major complication of solid organ transplant. This study details the clinicopathological and molecular features of 17 B-cell PTLDs observed in a single center series of 988 heart and/or lung transplant recipients.

METHODS

Cases were classified according to World Health Organization lymphoma classification and tested for Epstein-Barr Virus (EBV), clonality, histogenetic phenotypic (CD10, Bcl-6, MUM1, CD138), and genotypic (immunoglobulin and BCL-6 genes somatic hypermutation) markers.

RESULTS

This series of 17 PTLDs included: two B-cell monoclonal polymorphic PTLDs and 15 B-cell monomorphic PTLDs (13 diffuse large B-cell lymphomas [DLBCL] and 2 Burkitt lymphomas [BL]). EBV was detected in 9/17 cases. A monoclonal immunoglobulin variable (IGV) genes rearrangement was documented in 17/17 cases; IGV somatic hypermutation was found in 88% of cases, indicating a prevalent origin from germinal center (GC)-experienced B cells. Using immunophenotypic markers, three histogenetic profiles were identified: a) CD10/bcl-6/MUM1/CD138, mimicking GC B-cells; b) CD10-/bcl-6+/MUM1+/CD138-, reminiscent of B-cells at the latest phases of GC reaction; and c) CD10-/bcl-6-/MUM1+/CD138+/-, consistent with preterminally differentiated B-cells.

CONCLUSIONS

Correlation between morphology, histogenesis, and EBV status demonstrated a high degree of homogeneity in the two GC-related groups, mostly including EBV-negative cases with BL and DLBCL-centroblastic features; the third group, consisting of post GC EBV-positive cases, was histologically less homogeneous, as it included polymorphic PTLDs and DLBCL with immunoblastic and anaplastic features. The EBV-negative cases with GC histogenetic phenotype showed a slightly better outcome; however, such less aggressive prognostic trend was not confirmed by statistical analysis.

The impact of the World Health Organization classification and clonality assessment of posttransplant lymphoproliferative disorders on disease management

CONTEXT

The World Health Organization classification of posttransplant lymphoproliferative disorders divides them into 4 main categories.

OBJECTIVE

To classify cases of posttransplant lymphoproliferative disorders diagnosed in our institution according to the World Health Organization scheme and correlate the classification and clonality with clinical data.

DESIGN

Cases of posttransplant lymphoproliferative disorders were reviewed. They were classified according to the World Health Organization scheme. Clonality was determined by flow cytometry and/or polymerase chain reaction. Patients' charts were reviewed.

RESULTS

Thirty-one cases were identified. Median age was 33 years. There were 19 cases of kidney, 8 cases of liver, and 4 cases of bone marrow transplant. Immunosuppression consisted of cyclosporin A and prednisone (N = 24) or FK506 and prednisone (N = 7). Twenty cases (63%) were World Health Organization type 3, 7 cases (23%) type 2, 3 cases (6.4%) type 1, and 1 case type 4 posttransplant lymphoproliferative disorder. Ten patients received chemotherapy, 20 patients had reduction of immunosuppression, and 1 had no treatment. Follow-up was available on 25 patients. Seven (43.75%) of 16 with type 3 lesions with available follow-up died of their disease. Five of these patients received reduction of immunosuppression alone. Only 2 of 9 patients with type 3 disease who received chemotherapy died of disease. Two patients with type 2 disease died of unrelated causes. One patient is alive with disease; the remaining patients with types 1 and 2 disease are alive with no disease.

CONCLUSIONS

The World Health Organization classification of posttransplant lymphoproliferative disorders is valuable in the identification of subtypes. It helps identify early lesions (1 and 2) requiring reduction of immunosuppression and type 3 disease, which requires chemotherapy from the outset.

Comparative genome-wide profiling of post-transplant lymphoproliferative disorders and diffuse large B-cell lymphomas

Post-transplant lymphoproliferative disorders (PTLD) are a major complication of solid organ transplantation, representing a cause of severe morbidity and mortality. Apart from Epstein-Barr virus infection, knowledge of the pathogenesis of monoclonal PTLD is limited. Powerful analysis techniques, such as whole genomic DNA profiling (array comparative genomic hybridisation), can improve our understanding of PTLD pathogenesis. Whole genome profiling using the Affymetrix GeneChip Human Mapping 10 k 2.0 was performed on 20 PTLD cases and 25 cases of diffuse large B-cell lymphoma (DLBCL) from immunocompetent patients as a control group. Recurrent lesions were detected among all the samples. Chromosome 18q, 7q, 3q and 12 were the most common gains in the control group. Chromosomes 5p and 11p were commonly gained in PTLD-DLBCL. The latter had frequent losses of 6q, 17p, 1p and 9p. Chromosome 12p was the most frequent target of deletions among PTLD-DLBCL cases. Loss of heterozygosity (LOH) did not always match DNA loss: chromosome 10 seemed to be targeted by uniparental disomy in PTLD. Small deletions and gains, involving both known (BCL2 and PAX5) and unknown genes (ZDHHC14), were identified. These data suggest that PTLD share, at a lower frequency, common genetic aberrations with DLBCL from immunocompetent patients. The demonstration of 9p13 amplification emphasises the importance of PAX5 in PTLD. The combination of DNA copy number and LOH assessment lead to the hypothesis that uniparental disomy may be a potential mechanism in B-cell lymphomagenesis.

Posttransplant Lymphoproliferative Disorder in a Kidney-Pancreas Transplanted Recipient

Posttransplant lymphoproliferative disorders (PTLDs) are lymphoid proliferations or lymphomas that develop as a consequence of immunosuppression after solid organ or bone marrow transplantation and are mostly associated with an Epstein-Barr virus infection. The morphologic categories include different types of benign and malignant lymphoid proliferations. The majority of PTLDs is of B-cell origin with clonal rearrangements of the immunoglobulin genes. The PTLDs in solid organ transplants are reported to be either of host or of donor origin. Donor-related PTLDs frequently involve the allograft. We report a case of a 52-year-old woman recipient who developed simultaneously PTLDs in several organs 5 month after receiving a sex-mismatched renal and pancreas allograft. Immunosuppression regimen comprised antithymocyte globulin, tacrolimus, mycophenolate mofetil, and steroids. Pathologic features appeared as polymorphic PTLDs in the renal allograft, liver, and central nervous system (CNS). Molecular genetic studies revealed different clonal immunoglobulin heavy chain gene rearrangements in all 3 organs as determined by polymerase chain reaction (PCR). Epstein-Barr virus were detected by nested PCR and in situ hybridization in all 3 tumors. The PTLDs in liver and CNS were of host origin whereas the allograft kidney PTLD was found to originate from the male donor as shown by the simultaneous detection of female and male sex chromosomes by PCR and fluorescence in situ hybridization. The recipient died in consequence of the CNS involvement, after intracerebral hemorrhage with uncal and tonsillar herniation.

Posttransplant lymphoproliferative disorder of the lung in a renal transplant recipient treated successfully with surgery

Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid diseases that occur after solid organ and bone marrow transplantation. Lung-located PTLD has been reported in recipients of the heart, cord blood stem cells, lungs, and bone marrow transplants, but only four cases were reported previously after kidney transplantation. Thoracic location of PTLD must be regarded as an especially dangerous complication. The pathogenesis, and clinical and histological features of PTLD remain poorly defined but predisposing risk factors are becoming better understood. Namely, Epstein-Barr virus (EBV) and immunosuppressive agents appear to be such risk factors. There has been marginal success in treating PTLD using a number of treatment modalities, including combination chemotherapy with anti-CD20 or high-dose chemotherapy with stem cell rescue. We report a renal allograft recipient transplanted in March 2000, diagnosed with EBV-associated and lung-located PTLD. His initial immunosuppression consisted of tacrolimus, azathioprine, and steroids. Azathioprine was withdrawn in September 2001. In November 2001 a high-resolution computed tomography scan revealed two round masses in the right lung. The patient underwent right thoracotomy and resection of the lower and middle lobe. The diagnosis of PTLD was settled by intraoperative histopathological evaluation. The postoperative histological assessment confirmed the diagnosis and revealed positive staining for EBV. The patient remained in complete remission for 3 years with a well-functioning renal allograft, with current serum creatinine of 1.2 mg%. This case illustrates that the treatment of lung-located PTLD may be successful, but it depends on a combination of prompt diagnosis, reduction of immunosuppression, and of course surgery.

Posttransplantation lymphoproliferative disease with features of lymphomatoid granulomatosis in a lung transplant patient

A 58-year-old lung transplant patient developed worsening shortness of breath and indurated erythematous plaques on the lower left leg. A skin biopsy specimen revealed a dense angiocentric and angioinvasive infiltrate in the mid to reticular dermis and panniculus containing large, atypical lymphocytes with convoluted nuclei and prominent nucleoli. Immunohistochemical stains showed that the atypical cells were of B-cell origin, and that Epstein-Barr virus was present. Molecular studies demonstrated B-cell clonality. The patient was successfully treated with rituximab. The clinical and pathologic features in this case represent posttransplantation lymphoproliferative disease with features of lymphomatoid granulomatosis. The case also highlights the importance of clinical and pathologic examination of cutaneous lesions in the evaluation of lymphoproliferative disorders for patients undergoing transplantation.

Lymphoproliferative disorders after paediatric heart transplantation: a multi-institutional study

BACKGROUND

Post-transplant lymphoproliferative disorders (PTLD) are an important cause of morbidity and mortality after organ transplantation. We sought to better define the prevalence, pathology, current therapeutic approaches, and outcomes of PTLD in a large group of children who had received heart transplants.

METHODS

We assessed data on patients followed up at 19 centres in the Pediatric Heart Transplant Study (PHTS) from 1993 to 2002. Probability of freedom from PTLD was assessed along with details of presentation, pathology, treatment, and outcomes. Risk factors for survival and event-free survival were investigated.

FINDINGS

Of 1184 primary transplant recipients, 56 (5%) developed PTLD. Probability of freedom from PTLD was 98% at 1 year, 94% at 3 years, and 92% at 5 years. Mean time to PTLD was 23.8 months. Most common sites of disease were gastrointestinal tract (n=22, 39%) and respiratory system (n=14, 25%). Histology was polymorphic in 35 (65%) and monomorphic in 19 (35%). 47 of 48 cases were of B-cell origin, 39 of 45 (87%) were Epstein-Barr virus positive. Probability of survival was 75% at 1 year, 68% at 3 years, and 67% at 5 years after diagnosis. Death from graft loss was as frequent as death from PTLD.

INTERPRETATION

About 5% of paediatric heart-transplant recipients develop PTLD, almost always of B-cell lineage and driven by Epstein-Barr virus. Although many achieve satisfactory outcomes, mortality remains substantial with death due to progressive disease and allograft loss. Advances in management should focus on strategies to protect the allograft as well as improved therapies for PTLD.

Post-transplant lymphoproliferative disorders: molecular basis of disease histogenesis and pathogenesis

Post-transplant lymphoproliferative disorders (PTLD) represent a serious complication of solid organ and allogeneic bone marrow transplantation. PTLD generally display B-cell lineage derivation, involvement of extranodal sites, aggressive histology and clinical behaviour, and frequent association with EBV infection. The occurrence of IgV mutations in the overwhelming majority of PTLD documents that malignant transformation targets germinal centre (GC) B-cells and their descendants both in EBV-positive and EBV-negative cases. Analysis of phenotypic markers of B-cell histogenesis, namely BCL6, MUM-1 and CD138, allows further distinction of PTLD histogenetic categories. PTLD expressing the BCL6(+)/MUM1(+/-)/CD138(-) profile reflect B-cells actively experiencing the GC reaction and comprise diffuse large B-cell lymphoma (DLBCL) centroblastic and Burkitt lymphoma. PTLD expressing the BCL6(-)/MUM1(+)/CD138(-) phenotype putatively derive from B-cells that have concluded the GC reaction and comprise the majority of polymorphic PTLD and a fraction of DLBCL. A third group of PTLD is reminiscent of post-GC and pre- terminally differentiated B-cells that show the BCL6(-)/MUM1(+)/CD138(+) phenotype and are morphologically represented by either polymorphic PTLD or DLBCL immunoblastic. The molecular pathogenesis of PTLD involves infection by oncogenic viruses, namely Epstein-Barr virus, as well as genetic or epigenetic alterations of several cellular genes. At variance with lymphoma arising in immunocompetent hosts, whose genome is relatively stable, a fraction of PTLD are characterized by microsatellite instability as a consequence of defects in the DNA mismatch repair mechanism. Apart from microsatellite instability, molecular alterations of cellular genes recognized in PTLD include alterations of c-MYC, BCL-6, p53, DNA hypermethylation, and aberrant somatic hypermutation of proto-oncogenes.

Murine gammaherpesvirus 68 infection is associated with lymphoproliferative disease and lymphoma in BALB beta2 microglobulin-deficient mice

Human gammaherpesvirus infections are associated with development of lymphoproliferative disease. Understanding of the mechanisms of gammaherpesvirus lymphomagenesis during chronic infection in a natural host has been limited by the exquisite species specificity of human gammaherpesviruses and the expense of primates. Murine gammaherpesvirus gammaHV68 is genetically and biologically related to human gammaherpesviruses and herpesvirus saimiri and has been reported to be associated with lymphoproliferative disease in mice (N. P. Sunil-Chandra, J. Arno, J. Fazakerley, and A. A. Nash, Am. J. Pathol. 145:818-826, 1994). We report the development of an animal model of gammaHV68 lymphomagenesis in BALB/c beta2 microglobulin-deficient mice (BALB beta2m-/-). GammaHV68 infection induced two lymphoproliferative lesions: B-cell lymphoma and atypical lymphoid hyperplasia (ALH). ALH lesion histology resembled lesions of Epstein-Barr virus-associated posttransplant lymphoproliferative disease and was characterized by the abnormal infiltration of the white pulp with cells expressing the plasma cell marker CD138. Lymphomas observed in gammaHV68-infected animals were B220+/CD3- large-cell lymphomas. GammaHV68-infected cells were common in ALH lesions as measured by in situ hybridization with a probe specific for viral tRNAs (vtRNAs), but they were scarce in gammaHV68-infected spleens with normal histology. Unlike ALH lesions, gammaHV68 vtRNA-positive cells were rare in lymphomas. GammaHV68 infection of BALB beta2m-/- mice results in lymphoproliferation and lymphoma, providing a valuable tool for identifying viral and host genes involved in gammaherpesvirus-associated malignancies. Our findings suggest that gammaHV68 induces lymphomas via hit-and-run oncogenesis, paracrine effects, or stimulation of chronic inflammation.

TP53 gene mutation, an unfavorable prognostic factor for malignant lymphomas in autoimmune diseases

OBJECTIVES

To investigate whether mutations of the TP53 tumor suppressor gene are associated with a poor prognosis in lymphoproliferative disorders (LPD) developing in patients with a history of autoimmune disease (AID).

METHODS

Fifty patients, 15 males and 35 females ranging in age from 23 to 83 (median, 61) years, were examined. Rheumatoid arthritis (21 cases) is the commonest type of AID followed by systemic lupus erythematosus (10), dermatomyositis (9), progressive systemic sclerosis (4), and autoimmune hemolytic anemia (6). The interval between the diagnosis of AID and LPD ranged from 1 to 660 months (mean 42 months). Histological, immunohistological, and in situ hybridization studies revealed that 37 tumors were B cell lymphomas and 13 were T cell lymphomas with the Epstein-Barr virus genome present in the tumor cells in 24% of cases. Stage of disease was I in 15 cases, II in 5, III in 9, and IV in 21.

RESULTS

Polymerase chain reaction-single strand conformation polymorphism followed by direct sequencing revealed TP53 mutations in 45.9% of B cell and 53.8% of T cell lymphomas. The follow-up study revealed an unfavorable prognosis in cases with mutations compared with those without: the 1-year survival rate was 43.5 and 73.0% in B cell and 16.7 and 50% in T cell lymphoma, respectively.

CONCLUSIONS

The occurrence of a TP53 mutation is an unfavorable prognostic factor not only in B cell but also in T cell LPD in AID.

Characteristic pattern of chromosomal imbalances in posttransplantation lymphoproliferative disorders: correlation with histopathological subcategories and EBV status

BACKGROUND

Posttransplantation lymphoproliferative disorders (PTLDs) are a spectrum of lymphoid proliferations, occurring in immunosuppressed organ transplant recipients. They comprise early lesions, polymorphic (P-PTLD), monomorphic (M-PTLD), and Hodgkin/Hodgkin-like lymphoma PTLD (HL-PTLD) lesions. Most of them are associated with Epstein-Barr virus (EBV). Little is known about their genetic changes.

MATERIALS AND METHODS

We have studied 35 PTLDs[7 P-PTLDs (3/7 polyclonal IgH), 26 M-PTLDs (22 B-cell PTLD, 4 T-cell PTLD), 2 HL-PTLDs], using comparative genomic hybridization (CGH), a DNA-based technique allowing a screening of chromosomal imbalances without needing cultured cells. RESULTS.: Overall incidence of chromosomal imbalances: 51.5 %. The most frequent gains involved 8q24, 3q27 [4 cases each]; 2p24p25, 5p, 9q22q34, 11, 12q22q24, 14q32, 17q, 18q21 [2 cases each]. Nonrandom losses were 17p13 [4 cases]; 1p36, 4q [3 cases each]; 17q23q25, Xp [2 cases each]. Three high-level amplifications were detected: 4p16, 9p22p24, 18q21q23. In this latter imbalance, involvement of Bcl2 has been confirmed by FISH. The nonrandom CGH imbalances occurring in M-PTLD are usually described in lymphomas of immunocompetent patients and contain genes known to be involved in lymphomagenesis, while genomic abnormalities detected in half cases of EBV positive P-PTLD are mostly unknown.

CONCLUSION

This study reported nonrandom chromosomal imbalances in PTLD and also identified early genomic alterations in EBV positive P-PTLD. These results raise two questions: the role of such lesions in the development and progression of those EBV induced-lymphoproliferations and their clinical significance especially in P-PTLD.

Primary Cardiac Lymphoma in a Heart Transplant Recipient

Posttransplantation lymphoproliferative disease (PTLD) is one of the most serious complications of chronic immunosuppression in transplant recipients. Involvement of the cardiac allograft or development of lymphoma in the heart is extremely rare. We report a primary cardiac lymphoma that developed about 14 months after the operation in a cardiac recipient. The patient presented with vague abdominal complaints. Multiorgan failure developed within a short period of time, and the patient died. The diagnosis of "diffuse large cell lymphoma of B cell type" was made on postmortem examination.

Malignancies in organ transplant recipients

The development of cancer in organ transplant recipients is well known; depressed immunosurveillance induced by the use of immunosuppressive agents for prevention of rejection is a causative factor. The types of malignancies in renal transplant patients vary geographically and are influenced by the type of immunosuppressant used. In the present study in Japan, malignancies had developed in 2.6% of renal transplant recipients; the observed number/expected number ratio was 2.78. For the primary sites, the relative risk in Japan was quite different from that in Western countries, with a lower frequency of skin cancer, an absence of Kaposi's sarcoma and higher frequencies of renal and thyroid cancer in Japan. Epstein-Barr virus is an oncogenic virus causing lymphoproliferative disorders in immunocompromised hosts. In renal transplant recipients, who usually receive hemodialysis before transplantation, human T lymphotrophic virus (HTLV)-1 is also oncogenic and causes adult T-cell leukemia/lymphoma. The HTLV-1 in donor blood might be transmitted to transplant recipients via transfusion during hemodialysis. The epidemiology and characteristics of representative malignancies in transplant recipients are described, with a review of pertinent literature.

A case of plasmacytic hyperplasia arising in a kidney allograft salvaged with immunosuppression reduction alone

Post-transplant lymphoproliferative disorder (PTLD) is a well-known complication of organ transplantation. Plasmacytic hyperplasia (PH) is thought of as the mildest form of PTLD; however, a graftectomy is necessary in most situations. We experienced an interesting case of PH arising in a kidney allograft, which could be relieved with a reduction in immunosuppression. A 27-year-old female underwent a living-related kidney transplantation. A 3-month non-episode protocol biopsy unexpectedly showed the devastating appearance of polymorphic plasma cell infiltration into the graft intersitium, compatible with PH. The PH was located in the graft by radiographic examinations. The infiltration of plasma cell disappeared completely on the 6-month graft biopsy specimen following immunosuppression reduction and the graft is functioning, although it was damaged by a subsequent acute rejection. Our present case indicates that some PTLD can be completely cured with a reduction in immunosuppression alone. The diagnostic modality for the evaluation of PTLD cell extinction is necessary to maintain graft function with adequate immunosuppression thereafter.

Epstein-Barr Virus Primary Mismatching and HLA Matching: Key Risk Factors for Post Lung Transplant Lymphoproliferative Disease

BACKGROUND

Posttransplant lymphoproliferative disease (PTLD) in lung transplant recipients (LTRs) is potentially lethal with considerable morbidity. The role of donor (D)/recipient (R) HLA matching is unknown.

METHOD

We reviewed our LTRs from January 1994, when routine D/R Epstein-Barr virus (EBV) serologic screening was begun, through to January 2000. We examined whether D/R HLA match status influenced the risk of PTLD in EBV D+/R- mismatched LTRs.

RESULTS

There were 16 D+/R- EBV-mismatched LTRs, 5 (31%) of whom developed PTLD (from a total of 237 LTRs; 218 survived >30 days). There were only two other cases of PTLD among the non-EBV primary mismatched patients. All patients received baseline immunosuppression of cyclosporine, azathioprine, and prednisolone without cytolytics and ganciclovir prophylaxis if "at risk" from cytomegalovirus. The five PTLD cases were diagnosed 81 to 734 (median 116) days from transplantation; three involved the lung allograft and two others involved lymph nodes. All PTLD patients seroconverted for EBV, whereas 7 of the 11 remaining EBV-mismatched patients who did not develop PTLD did not seroconvert. In the 16 EBV primary mismatched patients, there were 4 of 66 HLA allele matches in the 11 PTLD-free patients versus 15 of 30 matches in the 5 PTLD patients (P<0.001). This resulted in 2 or more HLA (A/B/DR) matches in 4 of 5 patients with PTLD versus 0 of 11 in the PTLD-free group (P=0.003). All PTLD patients were treated with reduced immunosuppression and antiviral therapy. Only two of the five LTRs who developed PTLD died, one with progressive disease despite chemotherapy and the other from chronic allograft rejection.

CONCLUSION

A high degree of HLA matching in D/R EBV-mismatched LTRs significantly increases the risk of PTLD.

Plasmacytic hyperplasia--the early form of posttransplant lymphoproliferative disorder--with atypical morphology and clinical course in patient after liver transplantation: a case report

This case report describes an early lesion of posttransplant lymphoproliferative disorder (PLTD)--plasmacytic hyperplasia with atypical morphology. The 54-year-old patient was 4 months after liver transplantation due to alcoholic cirrhosis. The postoperative course had been uneventful without graft rejection episodes. Primary immunosuppressive therapy included tacrolimus and prednisone. On admission to the hospital the patient showed rapidly increasing jaundice, hepatomegaly, anemia, thrombocytopenia, and significant leukocytosis. A biopsy suggested generalized infection. Acute Epstein-Barr virus (EBV) infection was confirmed using serological methods. Despite treatment the patient died. On autopsy we found features of generalized infection. Histological examination of the enlarged lymph nodes showed plasmacytic hyperplasia despite lymph node atrophy. Plasmacytic hyperplasia, an early lesion of PTLD despite usually a good prognosis with multifactor therapy may display a rapid course that leads to death through intensified immunosuppression. In accordance with other reports we confirmed reactivation of EBV infection as the probable cause of plasmacytic hyperplasia. The lymph node morphology of plasmacytic hyperplasia may be atypical with atrophy of lymphoid components accompanying plasma cell proliferation.

Post-transplant plasma cell myeloma and polymorphic lymphoproliferative disorder with monoclonal serum protein occurring in solid organ transplant recipients

Post-transplant lymphoproliferative disorders are mostly Epstein-Barr virus-related, B-cell tumors that develop as a consequence of immunosuppressive therapy in recipients of solid organ or bone marrow transplants. These disorders range from reactive, polyclonal plasmacytic hyperplasia to those that are morphologically and genotypically indistinguishable from typical non-Hodgkin's lymphomas. Plasma cell myeloma occurring after solid organ transplantation is rare. We report three plasma cell myeloma post-transplant lymphoproliferative disorder cases and one polymorphic, monoclonal post-transplant lymphoproliferative disorder case associated with a monoclonal serum protein. All three plasma cell myeloma post-transplant lymphoproliferative disorder cases had clinical, radiologic, and pathologic features of conventional plasma cell myeloma. The one polymorphic post-transplant lymphoproliferative disorder case was associated with an IgM monoclonal serum protein and was morphologically indistinguishable from a lymphoplasmacytic lymphoma. Three of the four cases, including the one polymorphic post-transplant lymphoproliferative disorder case, were positive for Epstein-Barr virus encoded small RNA by in situ hybridization. One patient died of plasma cell myeloma post-transplant lymphoproliferative disorder. The remaining three patients are alive: two are completely free of post-transplant lymphoproliferative disorder, and one has shown partial response to therapy. We compare the clinicopathologic features of these cases with those in the literature.

Molecular heterogeneity of diffuse large B-cell lymphoma: implications for disease management and prognosis

Diffuse large B-cell lymphoma (DLBCL) accounts for approximately 40% of all B-cell non-Hodgkin lymphomas of the Western world. According to the "WHO classification of tumours of the haematopoietic and lymphoid tissues", the term DLBCL is likely to include more than one disease entity, as suggested by the marked variability of the clinical presentation and response to treatment of this disease. Such heterogeneity may reflect the occurrence of distinct molecular subtypes of DLBCL as well as differences in the host's immune function. In immunocompetent hosts, approximately 50% DLBCL carry one of two primary molecular lesions defining two distinct genotypic subgroups, characterized by activation of either the BCL-6 or the BCL-2 proto-oncogene. Conversely, the remaining DLBCL of immunocompetent hosts display one of several molecular lesions, each associated with a small subset of cases and including activation of the proto-oncogenes REL, MUC-1, BCL-8 and c-MYC. The molecular pathogenesis of immunodeficiency-associated DLBCL differs substantially from that of DLBCL in immunocompetent hosts. In fact, EBV infection is present in a large fraction of immunodeficiency-associated DLBCL, whereas it is consistently negative in DLBCL of immunocompetent hosts, probably reflecting the critical role of disruption of the immune system in this disease. Finally, the application of DNA microarray technology to DLBCL has led to the distinction of two disease variants: a germinal center like DLBCL and an activated peripheral B-cell like DLBCL. Overall the molecular features of DLBCL may identify prognostic categories of the disease and may represent a powerful tool for therapeutic stratification.