Lymphoproliferative disorders after liver transplantation: imaging features

Imaging of Bowel Lymphoma: A Pictorial Review

Intestinal lymphoma, although rare, is the second most common extra-nodal site of lymphoma, following stomach. It is usually secondary to systemic involvement and is predominantly of non-Hodgkin's subtype. In addition to the risk factors for lymphomas occurring elsewhere, certain risk factors are specific for intestinal lymphoma. These include enteropathies such as celiac disease and inflammatory bowel disease. Imaging is the cornerstone in the management of intestinal lymphoma. Contrast-enhanced computed tomography or positron emission tomography-computed tomography are the preferred modalities for diagnosis, staging, monitoring response to treatment, and for follow-up evaluation. Bowel lymphomas can have various morphological patterns on imaging; however, certain characteristic features, if present, may prove invaluable in its diagnosis. Hence, it is imperative to be acquainted with the myriad of imaging findings in bowel lymphoma and its complications which may not only help in vivo distinction from other commoner bowel lesions but alter the management accordingly.

Liver Transplant Imaging prior to and during the COVID-19 Pandemic

Background

The suspension of the surgical activity, the burden of the infection in immunosuppressed patients, and the comorbidities underlying end-stage organ disease have impacted transplant programs significantly, even life-saving procedures, such as liver transplantation.

Methods

A review of the literature was conducted to explore the challenges faced by transplant programs and the adopted strategies to overcome them, with a focus on indications for imaging in liver transplant candidates.

Results

Liver transplantation relies on an appropriate imaging method for its success. During the Coronavirus Disease 2019 (COVID-19) pandemic, chest CT showed an additional value to detect early signs of SARS-CoV-2 infection and other screening modalities are less accurate than radiology.

Conclusion

There is an emerging recognition of the chest CT value to recommend its use and help COVID-19 detection in patients. This examination appears highly sensitive for liver transplant candidates and recipients, who otherwise would have not undergone it, particularly when asymptomatic.

Post-lung transplantation abdominopelvic complications: the role of multimodal imaging

Lung transplantation (LT) is an established method for treating end-stage lung disease. Although most of the post-lung transplant imaging surveillance is focused on chronic lung allograft rejection, abdominopelvic complications have been reported in 7-62% of patients. The reported wide range of post-LT abdominopelvic complications is thought to be secondary to lack of current standardized definitions. These complications encompass a heterogeneous group of disorders including upper and lower gastrointestinal (GI) disorders, inflammatory conditions of solid organs, lymphoproliferative disorders, and neoplasms; each with varying pathophysiology, timing, severity, and treatment. Clinical manifestations of these complications may overlap or be masked by immunosuppression; therefore, imaging plays a paramount role in the early management and treatment.

Is there a difference in post-transplant lymphoproliferative disorder in adults after solid organ and haematologic stem cell transplantation? Experience in 41 patients

OBJECTIVE

To determine if there is a difference in post-transplant lymphoproliferative disorder (PTLD) in adults after solid organ transplantation (SOT) and haematologic stem cell transplantation (HST).

METHODS

In this institutional review board-approved Health Insurance Portability and Accountability Act-compliant study, we reviewed clinical data and imaging at the time of diagnosis in 41 patients (26 SOT and 15 HST) (31 males and 10 females; mean age 51 years) with histopathology-confirmed PTLD seen at our institution from 2004 through 2013. Statistical analysis was performed to assess difference in distribution and survival between SOT and HST cohorts.

RESULTS

SOT: 17 lung/cardiac, 8 renal and 1 liver transplant recipients. HST: 13 leukaemia/lymphoma and 2 patients with aplastic anaemia. Median time to diagnosis: SOT 3.0 years; HST 6 months (Fisher's exact test; p = 0.0011). There was no statistically significant difference in distribution of PTLD after SOT and HST with nodes (15/26; 8/15), lung (10/26; 5/15) and bowel (6/26; 4/15) being the most common sites. Hepatic (3/26) and neurologic (2/26) involvement occurred in only SOT cohort while splenic PTLD (5/15) occurred more often in HST cohort. Death occurred earlier in HST (9/15; 2 weeks) than SOT cohort (12/26; 11 months) (Wilcoxon test; p = 0.0188).

CONCLUSION

PTLD did not differ significantly in distribution between SOT and HST cohorts. PTLD after HST occurred early and had shorter survival.

ADVANCES IN KNOWLEDGE

The most common sites of PTLD were the nodes, lung and bowel. Distribution of PTLD does not differ significantly between patients with SOT and HST. PTLD after HST occurs early and has poor survival compared with PTLD after SOT.

Ocular post-transplant lymphoproliferative disorder

We report a case of an iris tumor with muttonfat keratic precipitates in a young patient after liver transplantation surgery. A 6yearold girl underwent liver transplantation for congenital biliary atresia and was subsequently immunosuppressed with oral cyclosporine. We examined her 5 years after transplantation because of a "white nodule in her left eye," which had been detected by her father one day before visiting our clinic. Ophthalmological examinations revealed symmetric visual acuity and normal afferent papillary reflex. Slitlamp examination revealed a depigmented iris nodule approximately3 × 2 mm with muttonfat keratic precipitates in the anterior chamber. Fundus examination was unremarkable, and computed tomography (CT) of the head, neck, and abdomen showed normal findings. Based on the suspicion of post-transplant lymphoproliferative disorder (PTLD), therapy was initiated, which included tapering cyclosporine and topical mydriatics. After 2.5 months, the lesion resolved and no more muttonfat keratic precipitates were identified in the anterior chamber. In this PTLD case, the patient presented with an iris nodule and muttonfat keratic precipitates, and the ocular PTLD presentation resolved spontaneously after tapering cyclosporine.

Hepatic transplantation: postoperative complications

Advances in surgical techniques and immunosuppression have made orthotopic liver transplantation a first-line treatment for many patients with end-stage liver disease. The early detection and treatment of postoperative complications has contributed significantly to improved graft and patient survival with imaging playing a critical role in detection. Complications that can lead to graft failure or patient mortality include vascular abnormalities, biliary abnormalities, allograft rejection, and recurrent or post-transplant malignancy. Vascular abnormalities include stenosis and thrombosis of the hepatic artery, portal vein, and inferior vena cava, as well as hepatic artery pseudoaneurysm, arteriovenous fistula, and celiac stenosis. Biliary abnormalities include strictures, bile leak, obstruction, recurrent disease, and infection. While imaging is not used to diagnose allograft rejection, it plays an important role in identifying complications that can mimic rejection. Ultrasound is routinely performed as the initial imaging modality for the detection and follow-up of both early and delayed complications. Cholangiography and magnetic resonance cholangiopancreatography are used to characterize biliary complications and computed tomography is used to confirm abnormal findings on ultrasound or for the evaluation of postoperative collections. The purpose of this article is to describe and illustrate the imaging appearances and management of complications associated with liver transplantation.

Therapeutic options in post-transplant lymphoproliferative disorders

Post-transplantation lymphoproliferative disorders (PTLD) are the second most frequent malignancies after solid organ transplantation and cover a wide spectrum ranging from polyclonal early lesions to monomorphic lymphoma. Available treatment modalities include immunosuppression reduction, immunotherapy with anti-B-cell monoclonal antibodies, chemotherapy, antiviral therapy, cytotoxic T-cell therapy as well as surgery and irradiation. Owing to the small number of cases and the heterogeneity of PTLD, current treatment strategies are mostly based on case reports and small, often retrospective studies. Moreover, many studies on the treatment of PTLD have involved a combination of different treatment options, complicating the evaluation of individual treatment components. However, there has been significant progress over the last few years. Three prospective phase II trials on the efficacy of rituximab monotherapy have shown significant complete remission rates without any relevant toxicity. A prospective, multicenter, international phase II trial evaluating sequential treatment with rituximab and CHOP-based chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone) is ongoing and preliminary results have been promising. Cytotoxic T-cell therapy targeting Epstein-Barr virus (EBV)-infected B cells has shown low toxicity and high efficacy in a phase II trial and will be a future therapeutic option at specialized centers. Here, we review the currently available data on the different treatment modalities with a focus on PTLD following solid organ transplantation in adult patients.

Associations between EBV serostatus and organ transplant type in PTLD risk: an analysis of the SRTR National Registry Data in the United States

In a prior multiorgan transplant database study, recipient Epstein-Barr virus (EBV) seronegativity was not associated with increased risk for posttransplant lymphoproliferative disorders (PTLD) in liver transplants (LTX), at variance with prior single center reports and with data from kidney and heart transplants (KTX and HTX). The Scientific Registry of Transplant Recipients (SRTR) in the United States is the only other registry with data on the required variables for comparison.Our study set comprised 112 756 KTX (580 PTLDs; 0.51%), 13 937 HTX (140 PTLDs; 1.0%) and 40 437 LTX (383 PTLDs; 0.95%) performed January 2003 onward. The unadjusted hazard ratio (HR) for PTLD if recipient EBV seronegative was 5.005 for KTX, 6.528 for HTX and 2.615 for LTX (p < 0.001 for all). In models adjusted for multiple covariates, the adjusted HR was 3.583 (p < 0.001) for KTX, 4.037 (p < 0.001) for HTX, 1.479 (p = 0.03) for LTX. Interaction models using EBV seropositive KTX as reference group showed significantly higher risk for all other EBV seronegative organ transplant groups and also for EBV seropositive LTX (AHR 2.053, p < 0.0001).Recipient EBV seronegativity is still significantly associated with risk for PTLD in LTX, though less so because of higher baseline risk in the EBV seropositive LTX group.

Posttransplant lymphoproliferative disease in liver transplant patients

Posttransplant lymphoproliferative disorders (PTLD) are a life-threatening complication following solid organ transplantation. Many posttransplant lymphomas develop from the uncontrolled proliferation of Epstein-Barr virus (EBV)-infected B-cells, whereas EBV-negative PTLDs were increasingly recognized within the past decade. Major risk factors for the development of PTLDs after liver transplantation are immunosuppressive therapy and the type of underlying disease: viral hepatitis, autoimmune liver disease, or alcoholic liver cirrhosis contribute to an increased risk for PTLD. Therapeutic regimens include reduction of immunosuppression, the anti-CD20 antibody rituximab, and chemotherapy, as well as new approaches using interferon-α and anti-interleukin-6 antibodies. Despite the different therapeutic regimens, mortality from PTLD remains high. Therefore, it is of major importance to identify patients at risk at an early stage of the disease. In this review, risk factors for PTLD development after liver transplantation, clinical presentation, diagnosis, and therapy are discussed.

Imaging of the transplant liver

As the number of patients with liver transplants continues to increase, radiologists need to be aware of the normal post-operative appearance of the different liver transplants currently performed along with the wide variety of complications encountered. The complications commonly affect the biliar and vascular systems and can include anastomotic bile leakage and biliary stenosis along with stenosis or obstruction of the hepatic artery, portal or hepatic veins and IVC. Other complications include parenchymal abnormalities such as hepatic infarction, organ rejection, localized collections and post transplant lymphoproliferative disorder. This article reviews and illustrates the role of imaging for pediatric transplantation including the role of interventional radiology.

Imaging findings in immunosuppressed patients with Epstein Barr virus-related B cell malignant lymphoma

OBJECTIVE

The purpose of this study was to describe multimodality imaging findings in immunosuppressed patients with Epstein-Barr virus (EBV)-related malignant lymphoproliferative diseases.

CONCLUSION

EBV-related malignant lymphoproliferative diseases share common features with other aggressive lymphomas, including a high degree of extranodal involvement, tumor vascularization, and tumor necrosis. Cognizance of the particular underlying diseases and conditions associated with the development of EBV-related lymphoproliferative diseases and associated imaging results should provide more accurate diagnosis.

Imaging of posttransplantation lymphoproliferative disorder after solid organ transplantation

Posttransplantation lymphoproliferative disorders (PTLDs) are a heterogeneous group of diseases that represent uncommon complications of transplantation and can lead to significant morbidity and mortality. PTLD is most prevalent during the first year following transplantation and occurs most frequently in multiorgan transplant recipients, followed by bowel, heart-lung, and lung recipients. It may involve any of the organ systems, with disease manifestation and the anatomic pattern of organ involvement being highly dependent on the type of transplantation. The current classification system includes four subtypes that have different prognoses requiring different treatment strategies. Tissue sampling is necessary for diagnosis and further subcategorization. The majority of cases are characterized by B-cell proliferation and are related to infection from Epstein-Barr virus. Knowledge of the distribution and radiologic features of PTLD allows the radiologist to play a pivotal role in making an early diagnosis and in guiding biopsy.

Intrahepatic cholestasis after liver transplantation

Biochemical cholestasis after liver transplantation is common and often has no clinical significance if biliary anastomosis strictures and leaks have been excluded. There is no agreed upon definition for severe cholestasis, but it is associated with a worse mortality. There has been little evaluation on risk factors, but these include cryoprecipitate and platelet transfusion intraoperatively, nonidentical blood group, suboptimal graft appearance, inpatient status before transplant, and bacteremia within the first month. Associated causes considered as early (<6 months) include ischemia-reperfusion injury, primary nonfunction, small-for-size graft syndrome, infection, drugs and acute cellular rejection. Late causes include hepatic artery thrombosis, chronic rejection, biliary complications, recurrent viral and cholestatic disease, and posttransplant lymphoproliferative disorder.

Posttransplant lymphoproliferative disorder in adult liver transplant recipients: a report of seventeen cases

Posttransplant lymphoproliferative disorder (PTLD) is a major complication of liver transplantation, but previous descriptions have been limited to case reports and small case series. We report a retrospective analysis of 17 consecutive cases of PTLD associated with liver transplantation. The median age at PTLD diagnosis was 47 years (range 19 - 63) with a median time of 25 months from liver transplantation to PTLD diagnosis (range 3 - 75). PTLD location was frequently extranodal (71%) and involved the transplanted liver (41%). PTLD histology consisted of nine (53%) monomorphic and eight (47%) polymorphic disease. EBV was present by in situ hybridization in 11 (79%) of 14 cases evaluated. Initial therapy included reduction in immunosuppression (RI) alone in 13 (76%) of 17 patients, resulting in 6 (46%) complete responses (CR) and 7 (54%) progressive disease (PD). Monoclonal CD20 antibody (rituximab) and CHOP chemotherapy were used as initial therapy or as second line after RI failure. Currently, five patients (29%) are alive in CR. Although detection and treatment of PTLD in liver transplant recipients remains problematic and upfront mortality is still high, long-term survival is possible. Further studies are necessary to better define treatment strategies.

Tonsil enlargement after liver transplantation in adults--reason enough for tonsillectomy? Two cases of tonsillar posttransplantation lymphoproliferative disease

Posttransplantation lymphoproliferative disease (PTLD) is a well-known complication of solid organ and bone marrow transplantation. It is agreed that the main causes of PTLD are chronic infection with Epstein-Barr virus (EBV); the intensity, rather then the type, of immunosuppression used; and underlying recipient disease. Hepatitis C virus (HCV) and cytomegalovirus, as cofactors of EBV infection, have been suggested to increase the risk of PTLD. Use of calcineurin inhibitors, anti-CD3 monoclonal antibody (OKT3), and antithymocyte globulin may increase the risk of PTLD. On the other hand, mycophenolate mofetil, sirolimus, and the anti-interleukin-2 receptor monoclonal antibodies Daclizumab and basiliximab have not been demonstrated to increase the risk of PTLD. The incidence of PTLD after liver transplantation (LT) is estimated to be 1.5-3%, but a tonsillar location is extremely rare in adults. Thus, little is known about the best diagnostic tools for and treatment by LT recipients with tonsillar PTLD. Here, we report 2 cases of adult LT recipients with tonsillar PTLD. Tonsillectomy was used as a diagnostic tool and treatment option and resulted in complete remission for >2 years. Considering the high mortality and diagnostic difficulties of PTLD, together with the relatively low risks of tonsillectomy, we recommend tonsillectomy for treating tonsil enlargement of unknown cause and suspected PTLD in LT recipients. A larger series of patients and prospective studies comparing different treatment options will be needed to substantiate our recommendation.

Post-transplant lymphoproliferative disease in liver transplantation

Post-transplant lymphoproliferative disease (PTLD) is a well recognized complication of solid organ transplantation and therapeutic immunosuppression, first reported in 1968. PTLD incorporates a spectrum of abnormalities ranging from a benign infectious mononucleosis-like illness to non-Hodgkin's lymphoma with nodal and extranodal site involvement. The first liver transplant was performed at our institution in January 1982. This retrospective study examined the incidence of PTLD, reason for the original transplants, presenting symptoms, radiological findings, immunosuppression regimens and outcomes of these patients. From a total of 2005 adult liver transplants, 23 patients (1.1%) were identified with PTLD. The average age of these patients at the time of transplant was 46.5 years, with a ratio of female-to-male of 14:9. Indication for transplant ranged from primary biliary cirrhosis (eight patients) to epitheloid haemangioendothelioma (one patient). The average time interval between transplant and diagnosis of PTLD was 50 months. Imaging abnormalities identified included generalized lymphadenopathy, liver and portal masses, splenic enlargement, bowel, eye, cerebral and neck involvement; and in two patients, no radiological abnormality. The most common histological findings ranged from B-cell non-Hodgkin's lymphoma (five patients) to early PTLD in one patient. Our rate of PTLD is lower compared with published literature and demonstrates a much longer time interval from transplant to occurrence of PTLD than previously appreciated. This could be secondary to a low immunosuppression therapy followed at our institution. From a few months to several years after liver transplantation, the radiologist needs to be alert to the possibility of PTLD and thorough imaging is required to detect the wide variety of potential presentations.

Pediatric liver transplantation: a pictorial essay of early and late complications

Orthotopic liver transplantation is currently the treatment of choice in patients with end-stage liver disease for which no other therapy is available. In children, segmental liver transplantation with living donor, reduced-size cadaveric, and split cadaveric allografts has become an important therapeutic option. However, the resulting expansion of the donor pool has increased the risk for postoperative vascular and biliary complications, which affect children more frequently than adults. Early recognition of these complications requires radiologic evaluation because their clinical manifestations are frequently nonspecific and vary widely. Doppler ultrasonography (US) plays the leading role in the postoperative evaluation of pediatric patients. Current magnetic resonance (MR) imaging techniques, including MR angiography and MR cholangiography, may provide a wealth of pertinent information and should be used when findings at US are inconclusive. Computed tomography is a valuable complement to US in the evaluation of complications involving the hepatic parenchyma as well as extrahepatic sites and is commonly used to guide percutaneous aspiration and fluid collection drainage. Familiarity with and early recognition of the imaging appearances of the various postoperative complications of pediatric liver transplantation are crucial for graft and patient survival.

Abdominal imaging and intervention in liver transplantation

Diagnostic imaging and interventional radiology play key roles in the evaluation and management of patients who are being evaluated for potential liver transplantation (LTX) and of those who have received a transplanted liver. Technical advances in imaging equipment and technique allow more accurate assessment and often obviate unnecessary or nontherapeutic surgery or invasive techniques such as catheter angiography.

A case of laryngeal posttransplantation lymphoproliferative disease

The development of posttransplant lymphoproliferative disease (PTLD) is strongly linked to infection with the Epstein-Barr virus (EBV), immunosuppression-state, the type of allograft, and EBV-seronegativity. A 18-month-old girl who had undergone living donor liver transplantation using the left lateral segment from her father was treated with tacrolimus and corticosteroid as an immunosuppressant regimen. She was readmitted 3 months after the transplant to evaluate the etiology of dyspnea and abdominal fullness as well as a decreased urine volume. She was diagnosed as an anastomotic stenosis of the hepatic vein for which she underwent balloon angioplasty. The treatment was repeated at postoperative month 5, 8, and 11. As postoperative 6 months, the result of the serological EBV-CA (IgG/IgM) was positive. In postoperative month 10, the EBV PCR serologic test become positive, and a laryngeal biopsy revealed PTLD. She was treated with acyclovir and gangyclovir as well as reduced immunosuppression. We report herein a rare case of laryngeal PTLD in a patient who had undergone living donor liver transplant with paternal allograft.

US of liver transplants: normal and abnormal

Whole-liver transplantation is an accepted and successful method of treating end-stage liver disease. As a result of the shortage of cadaveric livers, split-liver transplantation and living donor liver transplantation are becoming more commonplace. Ultrasonography (US) is the initial imaging modality of choice for detection and follow-up of early and delayed complications from all types of liver transplantation. Vascular complications include thrombosis and stenosis of the hepatic artery, portal vein, or inferior vena cava, as well as hepatic artery pseudoaneurysms and celiac artery stenosis. Biliary complications include leaks, strictures, stones or sludge, dysfunction of the sphincter of Oddi, and recurrent disease. Neoplastic disease in the transplanted liver may represent recurrent neoplasia or posttransplantation lymphoproliferative disorder. Parenchymal disease may take the form of a focal mass or a diffuse parenchymal abnormality. Perihepatic fluid collections and ascites are common after liver transplantation. Knowledge of the surgical technique of liver transplantation and awareness of the normal US appearance of the transplanted liver permit early detection of complications and prevent misdiagnosis.

Vascular and nonvascular complications of liver transplants: sonographic evaluation and correlation with other imaging modalities and findings at surgery and pathology

Liver transplantation is performed in adults and children to treat patients with irreversible liver damage when medical or other surgical treatment has failed. The most common indications for transplantation are cirrhosis secondary to fulminant acute hepatitis or chronic active hepatitis, sclerosing cholangitis, primary biliary cirrhosis, Budd-Chiari syndrome, inborn errors of metabolism, and unresectable but local hepatocellular carcinoma. This article reviews the sonographic findings in the preoperative evaluation of liver transplant recipients, briefly describes the surgical technique, and demonstrates normal postoperative findings in liver transplant recipients as well as complications associated with liver transplantation.

Thoracic radiology in kidney and liver transplantation

Renal transplantation accounts for more than half of all solid organ transplants performed in the U.S., and the liver is the second most commonly transplanted solid organ. Although abdominal imaging procedures are commonplace in these patients, there has been relatively little attention paid to thoracic imaging applications. Preoperative imaging is crucial to aid in the exclusion of infectious or malignant disease. In the perioperative time period, thoracic imaging focuses both on standard intensive care unit care, including monitoring devices and their complications, and on the early infections that can occur. Postoperative management is divided into three time periods, and the principles governing the occurrence of infections and malignancies are reviewed. Anatomic and pathologic aspects unique to kidney and liver transplantation patients are also discussed.

Radiology in liver transplantation

Imaging studies are becoming essential in the management of orthotopic liver transplantation (LT). They have a very important role in the preoperative evaluation and selection of suitable candidates. At the same time, they are essential in the early detection of postoperative complications, the recognition of which allows the prompt institution of appropriate therapeutic measures. Timely recognition of complications improves the success of LT; furthermore, some complications can be treated with interventional radiologic procedures, avoiding additional surgery. This article reviews the current application of diagnostic and interventional imaging in liver transplantation, both for cadaveric and living donor transplants.