Types Of Post-transplant Lymphoproliferative Disorders Research Articles

Ophthalmoplegia and Tumor Lysis Syndrome: An Uncommon Presentation of Posttransplant Lymphoproliferative Disorder

A 55-year-old man presented with 1 month of fatigue, nausea, vomiting, and weight loss, and blurry vision in his left eye. He has a history of type 1 diabetes mellitus after allogenic kidney and pancreas transplantation 15 years prior. He was found to have tumor lysis syndrome (TLS), total left-sided ophthalmoplegia and ptosis, and left cavernous, abdomen, and pelvic masses. Biopsy revealed an Epstein-Barr virus–negative diffuse large B-cell lymphoma, a type of posttransplant lymphoproliferative disorder (PTLD). It is essential to consider PTLD in transplant patients who present with TLS and compressive neurologic deficits.

A systematic review of post-transplant lymphoproliferative disorder after liver transplant.

e19045 Background: Post-transplant lymphoproliferative disorder (PTLD) is a complication after liver transplantation. This study aims to explore the association of PTLD with the immunosuppression, types of PTLD, clinical presentation, and outcomes. Methods: Following the PRISMA guideline, we searched the literature on PubMed, Cochrane, Embase, and clinicaltrials.gov. 1741 articles were screened and 22 studies were included. Results: Data includes 22,235 total patients who underwent a liver transplant, and 449 (2.0%) patients who developed PTLD were studied. Of the 394 patients where gender was reported, 226 were male and 168 were female. Post-transplant EBV status was positive for 63/115 (56%). 11 studies showed that the median time from transplant to the development of PTLD was 33.4 months. Among the histological types of PTLD, the monomorphic B-cell was the most common type with 127/235 (54%) cases, followed by early lesions 25/235, polymorphic 24/235, Hodgkin lymphoma 8/235, and monomorphic T-cell type 7/235. Treatment of PTLD involved reduction or cessation of the immunosuppressive drugs along with chemotherapy surgery and radiotherapy. Mortality data from 13 studies showed 68/259 (31.3%) patients died either due to PTLD or its complication. Conclusions: PTLD is rare but associated with high mortality after liver transplantation. EBV seropositivity is associated with PTLD in the majority of cases. Monomorphic PTLD is the most common type of PTLD after liver transplantation with DLBCL being the most common subtype. Abdominal symptoms and fever are among the most common symptoms. PTLD after Liver transplant a review of studies. [Table: see text]

A systematic review of post-transplant lymphoproliferative disorder after lung transplant.

e19046 Background: Post-transplant lymphoproliferative disorder (PTLD) is a serious complication after solid organ transplantation. This study aims to explore the association of PTLD diagnosed after lung transplant with infectious agents and immunosuppression regimen, explore types of PTLD, and their outcome. Methods: Following the PRISMA guideline, we searched the literature on PubMed, Cochrane, Embase, and clinicaltrials.gov. 1741 articles were screened and included five studies. Results: We analyzed data from five studies, n=13,643 transplant recipients with n=287 (2.10%) developed PTLD. Four studies showed that 32/63 (51%) PTLD patients were male and 31 (49%) were female. Three studies reported 53/55 (96.4%) patients were EBV positive at PTLD diagnosis. Courtwright. et al, reported that 217/224 (97%) PTLD was associated with either EBV positive donor or recipient. Four studies showed that the monomorphic B cell type 48/63 (76%) was the most common histological type of PTLD diagnosed with DLBCL the most common subtype 31/48 (64.6%). Data from 3 studies showed that the onset of PTLD following lung transplant varies with a median duration of 18.3 months (45 days to 20.2 years). Three studies showed that 26/55 (47.3%) patients had early-onset (≤ 1 yr of Tx) and 29/55 (52.7%) patients had late-onset PTLD (> 1 yr of Tx). Management of PTLD included a reduction in immunosuppression including corticosteroids, CNI, purine synthesis inhibitors, Rituximab, and chemotherapeutic agents. Three studies showed a mortality rate of 30/45 (66.7%) and 13/30 (43.3%) deaths were PTLD related. Conclusions: Our review concludes that PTLD is a serious complication, only 2% of lung transplant recipients developed PTLD. EBV seropositivity is the most factor associated with PTLD diagnosis. Monomorphic PTLD was reported as the most common type in the adult population and no association between gender and PTLD was found. The analysis shows that there is a slightly lower incidence of early (≤ 1 yr of Tx) than late-onset (> 1 yr of Tx) PTLD. Table 1 PTLD after a Lung transplant in adults - a review. [Table: see text]

A systematic review of post-transplant lymphoproliferative disorder after renal transplantation.

e19577 Background: Post Transplant Lymphoproliferative Disorder (PTLD) is a rare but severe complication following renal transplant. This study aims to explore the treatment modalities, histological types, and risk factors related to PTLD. Methods: Following the PRISMA guideline, we searched the literature on PubMed, Cochrane, Embase & clinicaltrials.gov. A total of 1741 articles were screened and 16 studies were included. Results: We reviewed 275915 adult patients who underwent renal transplantation out of which 2484 (0.9%) patients developed PTLD. Data for gender shows that 61.1% were males and 38.9% females. 576/2484 (23%) cases were EBV positive post-transplant. Seven studies showed the median duration from transplant to the development of PTLD was 80 months (5m-22yrs). Monomorphic PTLD was reported in 585 cases as the most common histological type. 5 studies suggested mortality due to PTLD was 41.38%. OS at 5 and 10 years was 55% and 41% respectively. Conclusions: Our study shows that PTLD is a rare complication after renal transplant which was more common in males. EBV did not show association with PTLD. Monomorphic is the most common histological type of PTLD after renal transplant. Our results show that it is associated with significantly high mortality. [Table: see text]

Distinctive Clinicopathologic Features of Monomorphic B-cell Post-transplant Lymphoproliferative Disorders in Children.

Post-transplant lymphoproliferative disorders (PTLDs) comprise a heterogeneous group of Epstein-Barr virus (EBV)-positive or negative lymphoid or plasmacytic lesions in solid organ or hematopoietic stem cell (HSC) transplant recipients. Although PTLDs in adults have been extensively studied, the clinicopathologic features of monomorphic B-cell PTLD in children, particularly EBV-negative forms, are still poorly understood. We retrospectively reviewed all our pediatric cases of monomorphic B-cell PTLDs diagnosed in the past 10 years. Clinical data were reviewed. Pathologic data including histologic types and EBV status were analyzed. Additional immunohistochemical stains, FISH studies, and TP53 gene mutational status were performed. 4 of 18 cases were EBV-negative. All 4 EBV-negative cases were strikingly confined to the gastrointestinal (GI) tract or abdominal lymph nodes, while tumors in EBV-positive cases were found at various anatomic sites; 2 of 4 EBV-negative cases carried mutations in TP53 gene. Our cohort also included 2 rare types of PTLD, one plasmablastic lymphoma and one high-grade B-cell lymphoma, not otherwise specified (HGBL, NOS). We report that monomorphic B-cell PTLDs in children have distinctive clinical and pathological features. More studies are needed to clarify whether and how much these pediatric PTLDs differ from their adult counterparts.

Phenogenomic heterogeneity of post-transplant plasmablastic lymphomas.

Plasmablastic lymphoma (PBL) is a rare and clinically aggressive neoplasm that typically occurs in immunocompromised individuals, including those infected with human immunodeficiency virus (HIV) and solid organ allograft recipients. Most prior studies have focused on delineating the clinico-pathological features and genetic attributes of HIVrelated PBL, in which MYC deregulation, Epstein-Barr virus (EBV) infection and, more recently, mutations in JAK/STAT, MAP kinase, and NOTCH pathway genes have been implicated in disease pathogenesis. The phenotypic spectrum of post-transplant (PT)-PBL is not well characterized and data on underlying genetic alterations are limited. This led us to perform comprehensive histopathological and immunophenotypic evaluation and targeted sequencing of 18 samples from 11 patients (8 males, 3 females; age range, 12-76 years) with PT-PBL; eight de novo and three preceded by other types of post-transplant lymphoproliferative disorders. Post-transplant PBL displayed morphological and immunophenotypic heterogeneity and some features overlapped those of plasmablastic myeloma. Six (55%) cases were EBV positive and five (45%) showed MYC rearrangement by fluorescence in situ hybridization. Recurrent mutations in epigenetic regulators (KMT2/MLL family, TET2) and DNA damage repair and response (TP53, mismatch repair genes, FANCA, ATRX), MAP kinase (KRAS, NRAS, HRAS, BRAF), JAK/STAT (STAT3, STAT6, SOCS1), NOTCH (NOTCH1, NOTCH3, SPEN), and immune surveillance (FAS, CD58) pathway genes were observed, with the mutational profiles of EBV+ and EBV– cases exhibiting both similarities and differences. Clinical outcomes also varied, with survival ranging from 0-15.9 years after diagnosis. Besides uncovering the biological heterogeneity of PT-PBL, our study highlights similarities and distinctions between PT-PBL and PBL occurring in other settings and reveals potentially targetable oncogenic pathways in subsets of the disease.

Non-Destructive Post-Transplant Lymphoproliferative Disorder Shows Distinct Clinical Features with HHV-6 Reactivation in a Subset

Background: Post-transplant lymphoproliferative disorders (PTLD) are a diverse group of lymphoid neoplasms arising after solid organ (SOT) or hematopoietic stem cell transplant (HSCT). They may resemble lymphomas in immunocompetent patients (monomorphic); present as destructive, heterogeneous lesions (polymorphic); or be non-destructive but mass-forming (non-destructive, previously known as 'early lesions'). PTLDs are often associated with Epstein-Barr virus (EBV) infection or reactivation, which likely functions as a driver in these cases. Non-destructive lesions may be challenging to diagnose in the absence of EBV. However, a significant fraction of PTLDs are EBV(-), including a subset of non-destructive lesions. The pathogenesis of these remains to be fully elucidated. Human herpesvirus 6 (HHV-6) reactivation is common during transplantation, occurring in up to 70% of HSCT and 80% of SOT patients. While it has been hypothesized that HHV-6 may play a role in PTLD, particularly in EBV(-) cases, the role of HHV-6 in the pathogenesis of PTLD remains underexplored. Methods: Following IRB approval, pathology archives at Weill Cornell/New York Presbyterian Hospital were searched to identify patients with a tissue diagnosis of PTLD and correlated with clinical information. A tissue microarray was constructed from blocks with sufficient tissue. Standard immunohistochemistry (IHC) and in situ hybridization for EBV-encoded RNA (EBER) were performed, and IHC conditions were optimized for antibodies against HHV-6 gp60/110 (Millipore Sigma, MAB853) and p41 (Santa Cruz Biotechnologies, 9A5D12). Statistical comparisons utilized Student's t-test and Fisher's exact test. Results: We identified 79 patients from 6/23/94-6/6/19 with a tissue diagnosis of PTLD. Morphologic subtype could be determined in 74, including 8 patients with non-destructive lesions. Compared to monomorphic or polymorphic, patients with non-destructive PTLDs were significantly younger (median age 9, p<0.01) and more likely status post heart transplant (5/8 cases, p<0.001, Table 1). By contrast, polymorphic PTLDs occurred relatively more frequently in HSCT patients (25/33 cases, p<0.01). All morphologic subtypes were frequently EBV+ (63-88%) but EBV positivity was greater in polymorphic than monomorphic lesions (p<0.05). While tissue testing failed on blocks > 20 years old, 13 PTLD cases from 12 patients had sufficient evaluable material for HHV-6 testing (Table 2). 9/12 patients had a SOT (8 renal, 1 heart) and 3 had HSCT. HHV-6 was identified in 5/13 lesions (38%), all of which were in SOT patients (Figure 1). EBER was detected in 8/13 lesions (62%). When stratified by PTLD subtype, 3/3 non-destructive PTLDs were HHV-6+ (100%). Two were EBER(-) and the remaining case only showed scattered EBER+ cells. Unfortunately, material was not available for testing the EBER+ non-destructive lesions. 2/9 of the monomorphic lesions tested (22%) were positive for both HHV-6 and EBER. While the series is limited, the association between HHV-6 and non-destructive lesions, compared to other types of PTLD, appears significant (p<0.05). EBV did not appear to be associated with HHV-6 status (p = 0.29). Conclusions: Non-destructive, monomorphic and polymorphic PTLDs show significant differences in timing, patient demographics and transplant type, suggesting that they may differ in associated risk factors affecting their pathogenesis. Confirming prior studies, we find non-destructive lesions tend to occur in younger patients, often following SOT as compared to HSCT and with a median time from transplantation of ~50 months. In addition, the presence of HHV-6 in the absence of (or with limited) EBV in the 3 non-destructive lesions tested raises the possibility that HHV-6 may play a role in the pathogenesis of this PTLD subtype that has yet to be defined. These findings are intriguing given the frequent reactivation of HHV-6 seen in transplant populations. HHV-6 has been variably associated with post-transplant complications including pneumonitis, delayed hematopoietic engraftment and graft versus host disease and thus received relatively more attention in the HSCT population. A causative role for HHV-6 in PTLD remains speculative, but these findings raise the possibility that clinicians treating the SOT population should also consider aggressively identifying and treating HHV-6 reactivation. Disclosures Rutherford: AstraZeneca: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Heron: Consultancy, Honoraria; Janssen Scientific Affairs: Consultancy, Honoraria; Juno Therapeutics Inc: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Verastem: Consultancy, Honoraria; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Post-transplant Lymphoproliferative Disorder of Appendix Mimicking Acute Appendicitis: A Case Report

Post-transplant lymphoproliferative disorder (PTLD) can be Epstein-Barr virus (EBV)-positive lymphoproliferations occurring in the first year after transplantation or EBV-negative lymphoma occurring many years after transplantation. Both B-cell and T-cell type of PTLD are described in the literature. In the gastrointestinal tract, the small and large intestine are the common sites of involvement. PTLD of the appendix is a lesser-known entity and cases described previously presented clinically as acute appendicitis. We report a case of EBV-negative B-cell PTLD of the appendix mimicking acute appendicitis in a live young renal allograft recipient 7 years after transplantation.

Reexamining post-transplant lymphoproliferative disorders: Newly recognized and enigmatic types.

Post-transplant lymphoproliferative disorders (PTLD) are a known risk for both solid organ transplant and stem cell transplant recipients. Overall transplant recipients have a six fold increase in risk for developing any kind of non-Hodgkin lymphoma and PTLDs occur in up to 10% of SOT recipients. Several new entities have been accepted or renamed in the 2018 update of the WHO classification of tumors of hematopoietic and lymphoid neoplasms, including florid follicular hyperplasia and extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT-lymphoma) (excluding common locations such as stomach and salivary gland). Other more rare types of PTLD have been reclassified including EBV-positive mucocutaneous ulcer, which is now a recognized diagnosis in its own right and should not be considered polymorphous PTLD. In this paper newly recognized PTLD entities and more unusual PTLDs will be examined.

Occurrence and prognostic relevance of CD30 expression in post-transplant lymphoproliferative disorders

Post-transplant lymphoproliferative disorders (PTLDs) are potentially fatal, often Epstein–Barr virus (EBV)-driven neoplasias developing in immunocompromised hosts. Initial treatment usually consists of a reduction in immunosuppressive therapy and/or rituximab with or without chemotherapy. However, patients who relapse do poorly, and new treatment options are warranted. With the introduction of the immunoconjugate brentuximab vedotin, the CD30 antigen has become an effectively targetable molecule. Therefore, we investigated the frequency and level of CD30 expression in PTLDs. We identified 108 patients with PTLDs diagnosed during 1994–2011, of whom 62 had adequate paraffin-embedded tissue for tissue microarray construction. Immunohistochemical expression of CD30 was consistently detected in all types of PTLD (overall 85.25%), including the monomorphic subtypes, and was correlated with a more favorable outcome. For diffuse large B-cell lymphoma (DLBCL)-type PTLD this was regardless of EBV status, and remained significant in multivariate analysis. Cell-of-origin had no independent prognostic value in our series of DLBCL PTLD.

The Impact of Immunophenotypic Subtypes and Treatment Regimens on Patient Outcomes in Monomorphic Post-Transplant Lymphoproliferative Disorders (Diffuse Large B-Cell Lymphoma)

Introduction: Post-Transplant Lymphoproliferative Disorders (PTLD) are a group of heterogeneous disorders that arise as a consequence of iatrogenic immunosuppression for solid organ or allogeneic bone marrow/stem cell transplantation. Though they all arise in a common clinical context, different types of PTLD differ with respect to their underlying biology, clinical presentation and treatment. The aims of this study were to: (1) Define the cell of origin (COO) of monomorphic Diffuse Large B-cell Lymphoma (DLBCL) PTLD and evaluate their impact on clinical presentation and survival and (2) assess the impact of different Rituximab containing treatment regimens on survival outcomes in monomorphic DLBCL PTLD patients.Methods: We conducted a retrospective review of our institutional databases to identify all the cases of monomorphic PTLD (DLBCL) diagnosed and treated at our medical center from 2000-2013. COO classification into germinal center B-cell like (GCB) and non-germinal center B-cell like (non-GCB) type was performed by immunohistochemistry using the Hans algorithm.Results: Cell of origin: 40 cases of monomorphic PTLD (DLBCL) were diagnosed during the study interval. Tissue material for COO subtyping was available for 25 patients. By immunohistochemistry 16/25 (64%) were non-GCB and 9/25 (36%) were GCB subtype, median age of presentation being 46 years (range 3-75) and 48 years (range 3-64), respectively. A trend towards EBV positivity (by in situ hybridization for EBV encoded RNA) was noted in the non-GCB group (75% vs. 33%) [p=0.09]. Non-GCB DLBCL PTLD presented earlier post-transplant at a median 1.5 years (range 0.2-15) vs. 3.9 years (range 0.7-17) for GCB cases. When comparing immunosuppressive therapy at the time of PTLD presentation, an association between Tacrolimus therapy and non-GCB phenotype was identified [p=0.03]. Non-GCB DLBCL PTLD demonstrated a trend towards higher rates of extra nodal involvement (88% vs. 44%) [p=0.06] and advanced stage disease (Stage III/IV 75% vs. 33%) [p=0.09]. No significant differences in organ transplanted, LDH, ECOG performance and IPI were observed. While acknowledging the heterogeneity of therapies administered, no significant differences in Progression Free Survival (PFS) (median PFS non-GCB = 17 months vs. GCB = 15 months [p=0.36]) and Overall Survival (OS) (median OS non-GCB = 33 months vs. GCB = 27 months [p=0.22]) were identified.Impact of Treatment: 35 adults (age≥18) were treated at our center. The four most common first line therapies administered were R-CHOP (14), R-EPOCH (7), Palliative Care (5) and Rituximab monotherapy (4). Five patients were given 4 other different therapies. In patients given Rituximab monotherapy, two patients presenting with stage I disease responded while two with stage IV disease progressed. When focusing on patients who commenced R-CHOP or R-EPOCH as their initial therapy, no significant differences in age, stage, LDH, extra nodal disease, ECOG performance status, IPI and immunosuppression therapy was identified between the groups. The complete response (CR) rate for R-CHOP was 50% vs. 71% for R-EPOCH. Primary refractory disease was present in 29% of patients receiving R-CHOP vs. 14% with R-EPOCH. Death during first line therapy occurred equally in both groups (14%). All four primary refractory disease patients in the R-CHOP arm died, while the one patient who was primary refractory to R-EPOCH is alive 3 years post autologous stem cell transplant. R-EPOCH demonstrated prolonged PFS (median PFS R-CHOP = 15 months vs. R-EPOCH not reached [p=0.049]) and prolonged OS (Figure 1) [p=0.036].Conclusions: (1) In monomorphic PTLD (DLBCL), the non-GCB subtype predominates and is associated with the use of Tacrolimus. It commonly presents with advanced stage disease and extra nodal involvement however, no difference in PFS and OS was noted when compared to GCB DLBCL PTLD. (2) R-EPOCH demonstrated prolonged PFS and OS when compared to R-CHOP. The survival differences reflect the higher rates of primary refractory disease in the R-CHOP group and the inability to salvage patients once they become relapse/refractory. Given the retrospective nature of our analysis, further studies in a larger cohort of patients are ongoing to validate these results. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Maintaining calcineurin inhibition after the diagnosis of post-transplant lymphoproliferative disorder improves renal graft survival

Post-transplant lymphoproliferative disorder (PTLD) is an uncontrolled proliferation of transformed lymphocytes fostered by immunosuppression. In addition to chemotherapy, treatment of PTLD includes a reduction of maintenance immunosuppression. Patients with PTLD have an increased risk of graft loss, suggesting that reduced immunosuppression strategy needs to be optimized with regard to graft outcome. Here we retrospectively reviewed 101 cases involving PTLD to identify the risks associated with graft loss. During a median follow-up of 70 months, 39 patients died and 21 lost their graft. Multivariate analysis found that an eGFR under 30 ml/min per 1.73 m(2) at PTLD diagnosis, a biopsy-proven acute rejection episode following reduction of immunosuppression, and the absence of calcineurin inhibition in maintenance immunosuppression are independent risk factors for allograft loss. Neither the type of PTLD nor the chemotherapy regimen was predictive of allograft failure. Histological analysis of graft biopsies showed that maintaining calcineurin inhibition after the diagnosis of PTLD reduced the risk of developing de novo anti-HLA antibodies and humoral rejection. Remarkably, calcineurin inhibitor maintenance was neither associated with higher mortality nor with worse progression-free survival. Thus, maintaining calcineurin inhibition at a reduced dose after the diagnosis of PTLD seems safe and may improve renal graft outcome, possibly through better control of the recipient's humoral immune response.

Early Posttransplant Lymphoproliferative Disease

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.

Post‐transplant lymphoproliferative disorders: clinicopathological analysis of 43 cases in a single center, 1990–2009

Post-transplant lymphoproliferative disorders (PTLDs) are a heterogeneous set of complications of organ transplantation associated with poor patient prognosis. We analyzed the clinicopathological features of PTLDs in 43 adult and pediatric recipients of solid organ or bone marrow transplantation at a large transplant service in the Republic of Korea between 1990 and 2009. Of 4545 solid organ and 747 bone marrow transplant recipients, 37 (0.81%) and 6 (0.8%), respectively, developed heterogeneous types of PTLDs. The cumulative incidences of PTLDs during this period were 1.79% (4/223) for heart transplant recipients, 0.78% (17/2192) for kidney transplant recipients, and 0.77% (16/2067) for liver transplant recipients. The patterns of disease onset, histology, and patient survival were associated with the types of organs transplanted. There is a trend for shorter overall survival (OS) in recipients with early-onset PTLDs and monomorphic PTLD histology, while kidney transplant recipients showed favorable OS. This study may be the first comprehensive analysis of the characteristics of PTLDs in Korean patients.

Epstein-Barr Virus-Associated High-Grade Anaplastic Plasmacytoma in a Renal Transplant Patient

Allograft transplant patients have an increased risk of developing polyclonal or monoclonal lymphoproliferative disorders, but high-grade anaplastic plasmacytomas are extremely rare in these patients. We present a renal transplant patient who developed multiple extramedullary high-grade anaplastic plasmacytomas in the oral cavity, the left maxillary antrum, the scalp, the thigh and the upper abdominal wall with no evidence of diffuse bone marrow infiltration. Epstein-Barr virus (EBV) mRNA transcripts were detected within the myeloma cells by in situ hybridization using EBER 1–2 probes. Following discontinuation of immunosuppression applied, the patient was treated with a cyclophosphamide-prednisone regimen followed by local irradiation, and a complete remission was achieved within four weeks. We concluded that EBV-associated high-grade anaplastic plasmacytomas constitute one more type of post-transplant lymphoproliferative disorder, and that despite their characterization as highly malignant neoplasms, their clinical behavior is not always aggressive.

Post-transplant lymphoproliferative disorders: a working classification

Categorization of the post-transplant lymphoproliferative disorders (PTLD) is essential because of their diverse clinical, histopathologic, immunophenotypic and genotypic nature. None of the well-established classifications address all of the types of PTLD that are now recognized. For that reason, a working classification of the PTLD was developed based on the preceding classifications, the PTLD literature and a review of adult PTLD. Besides recognizing plasmacytic hyperplasia in some post-transplant patients, the working classification includes the following types of PTLD: infectious mononucleosis-like, plasma cell rich, polymorphic, monomorphic, multiple myeloma-like, T-cell type, Hodgkin's disease-like, composite and not otherwise specified. Rare patients may also have lymphoid neoplasms that do not fall into any of these categories such as small B-cell lymphoid neoplasms. Criteria for use of this working classification require histopathology at a minimum and, in many cases, at least some ancillary studies. Epstein-Barr virus (EBV) positivity may aid in the recognition of a PTLD in some circumstances; however, it is not an absolute requirement for the diagnosis of a PTLD. EBV negative PTLD exist and have some characteristic features. Some, but not all, of these EBV negative cases, however, may represent coincidental lymphoid neoplasms that are not directly related to the patient's iatrogenic immunosuppression. Finally, a model of PTLD is presented which illustrates the relationship between histopathology, clonality, associated non-clonal T-cells, secondary genotypic abnormalities and responsiveness to a therapeutic decrease in immunosuppression.