Hepatosplenic gamma-delta T-cell lymphoma as a late-onset posttransplant lymphoproliferative disorder in renal transplant recipients

Classification and challenges in the histopathological diagnosis of peripheral T-cell lymphomas, emphasis on the WHO-HAEM5 updates

Mature T-cell lymphomas represent neoplastic expansions of T-cell lymphocytes with a post-thymic derivation. Most of these tumors feature aggressive clinical behavior and challenging histopathological diagnosis and classification. Novel findings in the genomic landscape of T-cell lymphomas are helping to improve the understanding of the biology and the molecular mechanisms that underly its clinical behavior. The most recent WHO-HAEM5 classification of hematolymphoid tumors introduced novel molecular and histopathological findings that will aid in the diagnostic classification of this group of neoplasms. The current review article summarizes the most relevant diagnostic features of peripheral T-cell lymphomas with an emphasis on the updates that are incorporated at the WHO-HAEM5.

T-cell neoplasms in the spleen

Hematopoietic neoplasms involving the spleen are uncommon, but T cell neoplasms involving the spleen are extremely rare. The rarity of splenic involvement by T cell neoplasms has resulted in a limited body of literature describing their splenic characteristics. As a result, our purpose in this review article is to provide and summarize some of the characteristics seen by different T cell neoplasms that may involve the spleen.

Hepatosplenic T-cell lymphoma arising in patients with immunodysregulatory disorders: a study of 7 patients who did not receive tumor necrosis factor-α inhibitor therapy and literature review

Hepatosplenic T-cell lymphoma (HSTCL) is a rare and aggressive extranodal T-cell lymphoma that can arise in patients with underlying immune disorders. Others have suggested that tumor necrosis factor (TNF)-α inhibitor therapy for immune disorders increases the risk of HSTCL. To assess for a potential relationship between HSTCL and the use of TNF-α inhibitors, we searched for patients with HSTCL and underlying immune disorders at our institution. We identified 7 patients with a median age of 38 years. Five patients had Crohn disease, 1 ulcerative colitis, and 1 rheumatoid arthritis. In 6 patients, medication history for the immune disorder was available: 6 patients received 6-mercaptopurine or azathioprine, and 2 patients received steroids; no patients received TNF-α inhibitors. In all 7 patients, the histologic, immunophenotypic, and cytogenetic findings were similar to cases of HSTCL that arise in immunocompetent patients. We reviewed the literature and identified 60 patients with immune disorders who subsequently developed HSTCL. These patients were treated with immunosuppressive drugs in 89%, TNF-α inhibitors in 56%, and both therapies in 54%, and 1 (2%) patient was treated with TNF-α inhibitors only. Our cohort and literature review indicates that TNF-α inhibitor therapy is not essential for the development of HSTCL in patients with immunodysregulatory disorders, and implies that immunosuppressive drugs or other factors (eg, genetic predisposition, chronic antigenic stimulation) may be more critical in the pathogenesis in this context. Although these data are observational, they have implications for the use of TNF-α inhibitors in patients with inflammatory bowel disease and other immunodysregulatory disorders.

[Hepatosplenic T-cell lymphoma: The problems of diagnosis and treatment]

In the past decade, a notable advance has been made in the understanding of the pathogenesis of NK/T-cell lymphomas; however, their diagnosis remains difficult because of their rarity and clinical and morphological variabilities. The paper generalizes the ten-year experience of the Hematology Research Center, Ministry of Health of Russia, in diagnosing and treating hepatosplenic T-cell lymphoma (HSTL), considers the problems of differential diagnosis with other hematological diseases occurring with similar clinical and laboratory symptoms, and lays down current approaches to the diagnosis and treatment of this condition. A clinician's view of the problem of diagnosis and treatment of this disease is given. HSTL is shown to be a heterogeneous group of diseases differing in a T-cell receptor chain gene rearrangement, the clinical course of the disease, and overall survival (OS). According to our data, 3-year OS was 12%; the median survival was 26 months. Two-year OS for γδ and αβ HSTL was equal to 25 and 70%, respectively. The difference in OS for the variants of HSTL failed to reach statistical significance (because the sample might be insufficient).

Lymphoproliferative disorder that resembles heptosplenic lymphoma during maintenance treatment for T-cell acute lymphoblastic leukemia

A 6-year-old male presented with a testicular mass, hepatosplenomegaly, and a pleural effusion while undergoing maintenance chemotherapy for treatment of T-cell acute lymphoblastic leukemia (T-ALL). He was subsequently diagnosed with a lymphoproliferative disorder that resembled hepatosplenic lymphoma (HSL). While the extranodal presentation and the protracted yet aggressive clinical course are consistent with HSL, the findings of monosomy 8 and polymorphic cell populations are unique and have not been previously described in this type of lymphoma.

Clinicopathological characteristics of posttransplant lymphoproliferative disorders of T-cell origin: single-center series of nine cases and meta-analysis of 147 reported cases

T-cell or natural killer (NK)-cell posttransplant lymphoproliferative disorder (T-PTLD) is a rare but severe complication after transplant. Here we present the clinicopathological features of a single-center series of nine cases. Additionally, we summarize the clinicopathological findings of 147 cases of T/NK-cell PTLD reported in the literature in an attempt to define subtype-specific characteristics. T/NK-cell PTLD occurs in patients of all ages, usually extranodally, and most frequently after kidney transplant. Organ specific incidence, however, is highest following heart transplant. Approximately one-third of T-cell PTLDs are Epstein-Barr virus (EBV)-related, with peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) being the most prevalent EBV-associated T-cell PTLD. A male predominance is observed, which is most striking in the EBV(+) group, particularly in PTCL, NOS. With a median posttransplant interval of 72 months, T-cell PTLDs are among the late-occurring PTLDs. Of the most common T-cell PTLDs, anaplastic large cell lymphoma (ALCL) has the best prognosis, whereas PTCL, NOS and hepatosplenic T-cell lymphoma (HSTCL) have the worst prognosis. EBV(+) cases seem to have a longer survival than EBV(-) cases, suggesting a different pathogenetic mechanism.

Pathobiology of T-cell and NK-cell lymphomas

T-cell and NK-cell lymphomas are uncommon lymphomas with an aggressive clinical course. The causes and precise cellular origins of most T-cell lymphomas are still not well defined. The WHO classification utilizes morphologic and immunophenotypic features in conjunction with clinical aspects and in some instances genetics to delineate a prognostically and therapeutically meaningful categorization. The anatomic localization of neoplastic T-cells and NK-cells parallels in part their proposed normal cellular counterparts and functions. T-cells of the adaptive immune system are mainly based in lymph nodes and peripheral blood, whereas lymphomas derived from T-cells and NK-cells of the innate immune system are mainly extranodal. This approach allows for better understanding of some of the manifestations of the T-cell and NK-cell lymphomas, including their cellular distribution, some aspects of morphology and even associated clinical findings.

Intensive induction chemotherapy followed by early high-dose therapy and hematopoietic stem cell transplantation results in improved outcome for patients with hepatosplenic T-cell lymphoma: a single institution experience

INTRODUCTION

Hepatosplenic T-cell lymphoma is a rare form of extranodal non-Hodgkin lymphoma, first recognized as a distinct entity in the Revised European-American Lymphoma classification. Typical presentation includes lymphomatous infiltration of spleen and liver, and peripheral lymphadenopathy is rarely seen. The prognosis is almost uniformly poor, and there are no prospective studies of treatment of HSTCL.

PATIENTS AND METHODS

For this report, we conducted a retrospective review of all pts who underwent treatment for HSTCL at our institution. Individual chart review was performed to report clinical presentation, management, and outcome.

RESULTS

We identified 14 pts with HSTCL managed at our center, 7 of which remain alive with median follow-up of 65.6 months. Six of 7 received alternative induction chemotherapy regimens such as ICE (ifosfamide, carboplatin, etoposide) or IVAC (ifosfamide, etoposide, high-dose cytarabine) as opposed to CHOP and all surviving pts had proceeded to undergo either autologous or allogeneic SCT.

CONCLUSION

Our results suggest that use of non-CHOP induction regimen and early use of high dose therapy and SCT consolidation may translate to improved survival for pts with HSTCL.

Hepatosplenic T-cell lymphoma and inflammatory bowel disease

OBJECTIVE

This article reviews the current literature and knowledge about hepatosplenic T-cell lymphoma (HSTCL), providing an overview of the clinical features, a description of its pathology and immunophenotypic traits in relation to other lymphomas. In addition, we explore the history of reported cases of hepatosplenic T-cell lymphoma in relation to the possible existence of a causal relationship between infliximab use and HSTCL. The treatments for HSTCL will be briefly addressed.

METHODS

A comprehensive literature search using multiple databases was performed. Keyword search phrases including "lymphoma," "hepatosplenic T-cell lymphoma," "Inflammatory bowel disease," "6-mercaptopurine," and "infliximab" were used in various combinations. In addition references from published papers were reviewed as well.

RESULTS

There are over 200 reported cases of HSTCL. Only 22 cases of hepatosplenic T-cell lymphoma are associated with IBD treatment. Clinicians usually reserve immunomodulators and biologics for moderate to severe IBD cases. The ultimate goal of therapy is to control inflammation and therefore allow mucosal healing. IBD patients demonstrating mucosal healing are less likely to undergo surgery and experience complications related to their disease. We manipulate the immune system with corticosteroids, immunomodulators, and biologics, therefore causing bone marrow suppression. With bone marrow suppression, malignant degeneration may begin through selective uncontrolled cell proliferation, initiating HSTCL development in the genetically susceptible.

CONCLUSION

Hepatosplenic T-cell lymphoma is a rare disease, often with a poor outcome. With the increasing number of reported cases of HSTCL linked to the use of infliximab, adalimumab, and AZA/6-MP, there appears to be an undeniable association of HSTCL development with the use of these agents. This risk is unquantifiable. When considering the rarity of cases and the multiple complications with uncontrolled disease, however, the benefit of treatment far outweighs the risk.

Long-Term Survival With Allogeneic Stem Cell Transplant and Donor Lymphocyte Infusion Following Salvage Therapy with Anti-CD52 Monoclonal Antibody (Campath) in a Patient with α/β Hepatosplenic T-Cell Non-Hodgkin's Lymphoma

Hepatosplenic T-cell non-Hodgkin's lymphoma (HSTCL) is a rare, aggressive form of NHL, with a median survival of approximately 8 months. We were able to successfully induce complete remission in a patient with alpha/beta HSTCL who was refractory to multiple prior chemotherapy regimens, using the humanized anti-CD52 monoclonal antibody alemtuzumab (Campath). Once disease was controlled, the patient was able to undergo allogeneic stem cell transplantation (SCT), which resulted in complete remission. Furthermore, upon relapse, we were able to re-induce complete clinical and molecular remission with donor lymphocyte infusions. At Day 655 (post-SCT), the patient remains in complete remission. These data suggest a potential role for alemtuzumab and allogeneic SCT in the treatment of T-cell NHL.

Hematologic abnormalities following renal transplantation

Recipients of renal allografts are surviving longer and, consequently, may experience a variety of complications related not only to the transplanted kidney, but also to the hematopoietic system. Common hematologic complications in the renal transplant patient include abnormalities of one cell line, such as post-transplantation erythrocytosis or anemia, that are often treatable with simple measures. Conversely, pathologies involving the leukocyte and platelet population often exist in the context of pancytopenia, which may be a manifestation of systemic infection (e.g., cytomegalovirus, human herpesvirus 8) or malignancy (post-transplantation lymphoproliferative disorders). Uncommon, but life-threatening, processes complicating renal transplantation include hepatosplenic gammadelta T-cell lymphoma and viral-induced hemophagocytic syndrome, both of which are associated with severe pancytopenia and, often, death. Since this patient population is often managed in a multidisciplinary fashion by nephrologists, infection specialists, transplant surgeons, hematologists, and internal medicine physicians, a succinct review of this topic is warranted.

Pediatric inflammatory bowel diseases and the risk of lymphoma: should we revise our treatment strategies?

Inflammatory bowel diseases (IBDs) are lifelong inflammatory gastrointestinal diseases starting in about one third of patients during childhood. Treatment strategies aim to control this chronic inflammatory process. Owing to recent advances in the understanding of IBD, immunosuppressive agents (mainly against TNFalpha directed) as well as biological drugs are more and more often used. This therapeutic approach clearly improved the clinical condition of the majority of patients with IBD. However, with this more aggressive treatment strategy, safety concerns clearly arise. Recently, the description of a series of a particularly severe form of T cell lymphoma in pediatric and young adult patients with IBD under immunomodulator and biological combination therapy raised the question of the risks of treatment-induced side effects or complications. As reviewed in the present article, there is a slightly increased risk of not only lymphoma development in IBD patients, potentially related to the inflammatory process, but also to the use of immunosuppressive therapies. On the basis of the literature data, were analyzed current treatment strategies for children with moderate-to-severe IBD, who are candidates to receive immunomodulator and/or biological agents potentially accelerating the risk of lymphoma development. Comparative clinical studies in IBD are still missing; however, it is prudent to think about adapting immunosuppressive therapies to the inflammatory process of the underlying disorder and if possible to reduce them to monotherapy. Alternative treatment strategies for heavy immunosuppression exist (eg, enteral nutrition in Crohn disease or colectomy in patients with ulcerative colitis) and should be considered whenever appropriate. There is a major need for comparative studies before evidence-based guidelines can be established for safest and best treatment strategies of pediatric patients with IBD.

Hepatosplenic gamma-delta T-cell lymphoma: clinicopathological features and treatment

BACKGROUND

Hepatosplenic T-cell lymphoma (HSTCL) is a rare peripheral T-cell lymphoma; treatment with standard anthracycline-containing chemotherapy regimens has been disappointing, and an optimal treatment strategy for this patient population has not yet been determined.

METHODS

We identified 15 cases of pathologically confirmed HSTCL in the institution's database. Clinical characteristics and treatment results were reviewed.

RESULTS

Complete responses (CRs) were achieved in 7 of 14 patients who received chemotherapy. Achievement of CR was followed by hematopoietic stem-cell transplantation in three patients. Median duration of CR was 8 months (range 2 to 32+ months) with four patients currently alive and in CR at 5, 8, 12, and 32 months, respectively. Median overall survival (OS) was 11 months (range 2 to 36+ months). Patients who achieved a CR had a median OS of 13 months, compared with 7.5 months in patients who did not achieve a CR. Risk factors associated with worse outcome included male gender, failure to achieve a CR, history of immunocompromise, and absence of a T-cell receptor gene rearrangement in the gamma chain.

CONCLUSION

A better understanding of the pathophysiology of HSTCL and new therapeutic strategies are needed.

Preclinical studies in rats and squirrel monkeys for safety evaluation of the bivalent anti-human T cell immunotoxin, A-dmDT390-bisFv(UCHT1)

The bivalent anti-human T cell immunotoxin A-dmDT390-bisFv(UCHT1) for treatment of patients with T cell malignancies is a single chain fusion protein composed of the catalytic domain and translocation domains of diphtheria toxin fused to two tandem sFv molecules reactive with human CD3 epsilon. This immunotoxin selectively kills CD3 epsilon positive T cells. To determine the maximum tolerated dose (MTD), pharmacokinetics and immunogenicity of A-dmDT390-bisFv(UCHT1), rat and squirrel monkey studies were performed. In both animal studies, animals received either 0, 2.5 (low), 25 (medium), or 56.25 microg/kg (high) of A-dmDT390-bisFv(UCHT1) intravenously twice daily for four consecutive days. Although transient elevation of liver transaminases in the high groups was observed, the A-dmDT390-bisFv(UCHT1) administration did not affect liver function, renal function, the hemogram, or produce serious organ histopathology. Adverse events included transient lethargy, inappetence and weight loss in high groups. A-dmDT390-bisFv(UCHT1) plasma half life was 26.95 min in rats and 18.33 min in squirrel monkeys. Immune responses to A-dmDT390-bisFv(UCHT1) were minimal in squirrel monkeys and mild in rats. In vitro cytokine release, T cell activation and CD3 epsilon receptor occupancy assays using human PBMC were further performed since rat and squirrel monkey T cells do not react with A-dmDT390-bisFv(UCHT1). A-dmDT390-bisFv(UCHT1) did not induce cytokine release or T cell activation. The A-dmDT390-bisFv(UCHT1) concentration for 50% CD3 epsilon receptor occupancy was 7.4 nM. The MTD of 200 microg/kg total provides a dose level sufficient for anti-tumor activity in vitro and in a rodent model. Therefore, we propose that this agent is a promising drug for patients with surface CD3+ T cell malignancies.

Post-transplant hepatosplenic T-cell lymphoma successfully treated with HyperCVAD regimen

Hepatosplenic T-cell lymphoma (HSTL) is an aggressive lymphoma. In post-transplant immunosuppressed patients, HSTL is usually rapidly fatal. We report successful treatment of post-transplant HSTL in a 50-year-old renal allograft recipient by reducing immunosuppression and using intensive chemotherapy consisting of alternating cycles of HyperCVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone) and MTX/HiDAC (methotrexate, Ara-C). Remission is ongoing at 8+ years. Literature review identified another 20 cases of HSTL in solid organ transplant recipients: median survival was 4 months; no other patients survived beyond 12 months. Bone marrow involvement was universal, but changes were often subtle: 6 of 12 cases had nondiagnostic examinations earlier on. High index of suspicion may lead to more timely diagnosis of this uncommon form of post-transplant lymphoproliferative disorder, and treatment with intensive chemotherapy such as HyperCVAD may be curative.

T-cell and NK-cell posttransplantation lymphoproliferative disorders

Posttransplantation lymphoproliferative disorders (PTLDs) of T-cell or natural killer (NK)-cell origin are an uncommon heterogeneous group of lymphoid proliferations that fulfill the criteria for one of the T- or NK-cell lymphomas/leukemias. This report summarizes 130 T/NK-cell PTLDs reported in the literature or presented at the Society for Hematopathology/European Association for Haematopathology Workshop on T/NK-cell malignancies. The T/NK-cell PTLDs occur at a median of 66 months following transplantation and are usually extranodal. The most common types reported are peripheral T-cell lymphoma, unspecified, and hepatosplenic T-cell lymphoma. Approximately one third are Epstein-Barr virus (EBV)+. The median survival is 6 months. EBV+ cases have a significantly longer survival than EBV- cases, even when indolent T-cell large granular lymphocytic leukemias are included among the EBV- cases. Many T/NK-cell PTLDs have been treated with chemotherapy, often together with decreased immunosuppression, but there are infrequent patients who have done well without chemotherapy or radiation.

Hepatosplenic and other gammadelta T-cell lymphomas

The 2005 Society for Hematopathology/European Association for Haematopathology Workshop session 11 was dedicated to hepatosplenic T-cell lymphoma (HSTCL). HSTCL is a rare aggressive type of extranodal lymphoma characterized by hepatosplenomegaly, bone marrow involvement, and peripheral blood cytopenias. HSTCL exhibits a distinctive pattern of infiltration; tumor cells preferentially infiltrate the sinusoids of the splenic red pulp, liver, and bone marrow. The tumor cells have a nonactivated cytotoxic T-cell immunophenotype and frequently carry a recurrent cytogenetic abnormality, isochromosome 7q. Most cases express the gammadelta T-cell receptor, but cases can have an alphabeta phenotype and are considered to be a variant of the disease. Although HSTCL is the prototype peripheral T-cell lymphoma expressing the gammadelta T-cell receptor, non-HSTCL proliferations of gammadelta T cells can involve other extranodal sites, mainly skin and mucosa. These gammadelta T-cell lymphomas display marked heterogeneity in clinical and histologic features. In contrast with HSTCL, non-HSTCL gammadelta T-cell lymphomas frequently have an activated cytotoxic phenotype and most likely are not a single disease entity.

Pathobiology of Peripheral T-cell Lymphomas

Peripheral T-cell lymphomas (PTLs) are uncommon, accounting for fewer than 10% of all non-Hodgkin lymphomas. Success in therapy of the PTLs has lagged behind that of aggressive B-cell lymphomas, and most PTLs have a poor prognosis. The molecular pathogenesis of most PTLs is also poorly understood. In the WHO classification, clinical features, in conjunction with morphological and immunophenotypic criteria, are relied on to define most disease entities.

Functionally, T-cell lymphomas are related to the two major arms of the immune system, the innate and adaptive immune systems. NK cells and T cells of the innate immune system recognize antigen in the absence of MHC antigens and are involved in mucosal immunity. The lymphomas derived from these cells often involve cutaneous and mucosal sites. The expression of cytotoxic molecules in these lymphomas may predispose to apoptosis by tumor cells and normal bystander cells. Hepatosplenic T-cell lymphoma is a systemic disease derived from functionally immature innate effector cells, most often of γδ T-cell origin. In contrast, most nodal T-cell lymphomas belong to the adaptive immune system.

Angioimmunoblastic T-cell lymphoma (AILT) is mostly likely derived from follicular helper T-cells (TFH), a finding that explains many of its pathological and clinical features. Studies of these neoplasms may assist in further unraveling the functional diversity of their normal counterparts.

Post transplant T-cell lymphoma: a case series of four patients from a single unit and review of the literature

Post-transplant lymphoproliferative disorders (PTLDs) occur in approximately 1% of renal graft recipients. Of these, up to 15 percent are of the T-cell type. In this study, we present four cases of T-cell lymphoma from our renal transplant population, each of whom presented with non-specific symptoms, pancytopenia and/or liver dysfunction, with no obvious lymphadenopathy. They were all diagnosed with rare subsets of T-cell PTLD that included hepato-splenic T-cell lymphoma and anaplastic large cell lymphoma (ALCL). At the time of presentation, the patients were too ill for treatment to be initiated and succumbed to their illness. Increased awareness of this condition may allow for earlier diagnosis and improve its prognosis.

TIA-1 expression in hairy cell leukemia

We measured T-cell intracellular antigen-1 (TIA-1) expression in neoplastic cells from patients with hairy cell leukemia. Five of nine cases were positive for cytoplasmic TIA-1, with a small, dot-like, granular expression pattern. However, neoplastic cells were granzyme B- and perforin- negative in all cases. Other positive markers were CD20 in 9/9 cases, CD19 in 9/9 cases, DBA44 in 8/9 cases, LeuM5(CD11C) in 8/9 cases, IL-2R(CD25) in 7/9 cases, CD103 in 7/9 cases, FMC7 in 6/9 cases, and tartrate- resistant acid phosphatase in 5/7 cases. We also analyzed TIA-1 expression in 94 B cell lymphomas, including 19 diffuse, large cell lymphomas, 19 mantle cell lymphomas, six follicular lymphomas, two extranodal marginal zone B-cell lymphomas, 13 nodal marginal zone B-cell lymphomas, one mediastinal large-cell lymphoma, 19 diffuse small-cell lymphomas, 14 myelomas, and one splenic lymphoma with villous lymphocytes. All cases were negative for TIA-1 expression. Based on these findings, TIA-1 expression in neoplastic cells of low-grade B-cell lymphomas may be a good diagnostic marker for hairy cell leukemia. Moreover, TIA-1 reactivity in lymphomas does not necessarily indicate a T- or NK-cell derivation.

Splenic involvement by peripheral T-cell and NK-cell neoplasms

In contrast to B-cell lymphomas, the literature on the splenic pathology of peripheral T-cell and NK-cell lymphomas is limited. Several different patterns of splenic involvement can be observed in peripheral T-cell and NK-cell lymphomas: 1) solitary or multiple fleshy nodule, which is seen predominantly in tumors rich in large cells; 2) diffuse red pulp involvement, which is the commonest pattern; 3) colonization of periarteriolar shealth; and 4) patchy haphazard involvement. However, the miliary small nodule pattern commonly observed in low-grade B-cell lymphomas is practically never seen. In hepatosplenic T-cell lymphoma and T-cell large granular lymphocyte leukemia, the pattern of splenic involvement is rather stereotyped, with diffuse red pulp infiltration and preservation of the sinus/pulp cord architecture, and without formation of nodules. The pattern of involvement is variable from case to case in peripheral T-cell lymphoma unspecified, and there can be associated prominent hemophagocytosis or a masking component of epithelioid granulomas. Aggressive NK cell leukemia and extranodal NK/T cell lymphoma show predominatly red pulp involvement, although the tumor cell density can vary from field to field; blood vessel walls are commonly infiltrated and there can be areas of necrosis.

Anaplastic lymphoma kinase (ALK) protein expressing lymphoma after liver transplantation: case report and literature review

Most post transplantation lymphoproliferative disorders (PTLDs) are Epstein-Barr virus (EBV) associated B cell proliferations. We report a case of aggressive anaplastic large cell lymphoma expressing the anaplastic lymphoma kinase (ALK) protein in a 58 year old man who had previously undergone liver transplantation. A definite diagnosis was not possible on histopathological examination. Immunostaining clearly showed a predominant population of small irregular lymphocytes, admixed with large cells strongly positive for CD30, epithelial membrane antigen, and the ALK protein. Neoplastic cells were of the T/cytotoxic phenotype. In situ hybridisation with EBV encoded early RNA probes showed only a few scattered positive non-neoplastic small lymphocytes. Polymerase chain reaction analysis of immunoglobulin and T cell receptor rearrangements was negative. The NPM-ALK fusion transcript associated with the t(2;5) translocation was detected by reverse transcription polymerase chain reaction. A review of the literature revealed 76 cases of T cell PTLD, showing a broad spectrum of morphological features and clinical behaviour. Most of these cases were EBV negative (61 of 76) and occurred after renal transplantation (48 of 76). To our knowledge, this is the first case of ALK positive lymphoma occurring in the setting of organ transplantation. This observation stresses the need for accurate immunostaining for diagnosing this rare, apparently aggressive, lymphoma in immunosuppressed patients.

Fluorescence in situ hybridization study of chromosome 7 aberrations in hepatosplenic T-cell lymphoma: isochromosome 7q as a common abnormality accumulating in forms with features of cytologic progression

Hepatosplenic gamma delta T-cell lymphoma (HS gamma delta TCL) is a rare and aggressive subtype of peripheral T-cell lymphoma that has been associated cytogenetically with the isochromosome 7q [i(7)(q10)]. The incidence of this aberration and its relevance to pathogenesis of HS gamma delta TCL is still unknown. We investigated the status of chromosome 7 in 12 HSTCL cases, including nine with a typical gamma delta phenotype, one with a so-called T-cell receptor (TCR)-silent phenotype, and two with the variant alpha beta phenotype. We analyzed available fresh and archival material using a dual-color interphase fluorescence in situ hybridization (FISH) approach with 7p and 7q probes. A significant population of cells with predominance of 7q signals was detected in 10 cases (eight gamma delta, one alpha beta, and one TCR silent), and two lymphomas did not show clonal 7p/7q signal imbalances. In four of 10 cases with chromosome 7 aberrations, a hybridization pattern indicative of the presence of one chromosome 7 and one i(7)(q10) was found. In four other cases, the configuration of signals (2 x 7p/3 x 7q) suggested the presence of the i(7)(q10) and additional structural aberrations involving the second chromosome 7. In two cases, including one alpha beta phenotypic variant, a variety of FISH patterns equivalent to two to five copies of i(7)(q10) or numerical and structural aberrations of second chromosome 7 has been detected. These findings support cytogenetic data pointing to a characteristic association of i(7)(q10) with HSTCL, irrespective of the immunophenotype of malignant cells. An increased number of 7q signals was found in three cases with cytologic features of progression, indicating a tendency of HSTCL to multiply the i(7)(q10) chromosome during evolution.

Hepatosplenic gammadelta-T-cell lymphoma with leukemic course after renal transplantation

Hepatosplenic gammadelta-T-cell lymphoma (HSTCL) is a rare extranodal T-cell non-Hodgkin's lymphoma (T-NHL) with only 46 well-documented cases in medical literature. Notably, a relatively high number of these case reports (15%) describe the occurrence of HSTCL after solid organ transplantation. We describe the case of a 45-year-old man who developed a leukemic HSTCL 5 years after renal transplantation and continous immunosuppression with cyclosporine A and prednisolone. After a rapid clinical course, the patient died and autopsy was performed. The malignant lymphocytes showed a natural killer-like gammadelta-T-cell phenotype (CD2(+), CD3(+), CD7(+), TCR gammadelta(+), CD56(+), TIA-1(+), CD4(-), CD8(-), and TCR alphabeta(-)) and infiltrated the sinusoids of liver and the red pulp of the spleen. Cytogenetically, an isochromosome 7q, trisomy 8, Y-loss, and a translocation t(1;4) was detectable. This case shows the difficulties of recognizing HSTCL early in the clinical course and underlines that all types of T-NHL, nodal as well as extranodal, have to be considered in the differential diagnosis of posttransplantation lymphoproliferative disorders. Moreover, HSTCL seems to occur as a specific late complication of solid organ transplantation.

Extranodal cytotoxic T-cell lymphoma in a patient with X-linked agammaglobulinaemia

This report documents the occurrence of an extranodal cytotoxic peripheral T-cell lymphoma (PTCL) in a patient with X-linked agammaglobulinaemia (XLA). The diagnosis was based on the immunohistochemical detection of T-cell antigens and of the cytotoxic proteins TIA1 and Granzyme B in the tumour cells. This report provides further evidence that cytotoxic lymphomas are part of the differential diagnosis of neoplasia in patients with immunodeficiencies.

T Cell and NK Cell Lymphoproliferative Disorders

This review covers the diagnosis and management of natural killer and peripheral T-cell lymphomas (PTCL). Problems with PTCL include their rarity, representing usually 10-15% of non-Hodgkin's lymphomas in the Western Hemisphere, morphologic heterogeneity, and lack of immunophenotypic markers for clonality. Additionally, their clinical behavior is variable and may not correlate with morphology.

Dr. Kinney gives a general overview of the diagnosis of PTCL and NK cell neoplasms. Emphasis will be placed on extranodal T cell and natural killer (NK) cell lymphomas such as hepatosplenic lymphoma, subcutaneous panniculitis-like lymphoma and nasal/nasal type T/NK-cell lymphoma. The use of ALK gene regulation in the classification of anaplastic large cell lymphoma is also reviewed.

Dr. Loughran describes current understanding of the pathogenesis of large granular lymphocyte (LGL) leukemia. The discussion focuses on LGL leukemia as an instructive model of dysregulated apoptosis causing both malignant and autoimmune disease. Current management options and mechanisms of therapeutic response are also described.

Dr. Greer addresses whether PTCL should be treated differently from the more common diffuse large B cell lymphomas. He discusses the therapeutic options for anaplastic large cell lymphoma (ALCL), from a conservative approach for primary cutaneous ALCL to combination chemotherapy for the highly chemosensitive ALCL expressing anaplastic lymphoma kinase. He reviews therapy options for the extranodal subtypes of PTCL by drawing from series in adults, pediatrics, dermatology, and the Far East.