Influence of donor age on liver transplantation outcomes: A multivariate analysis and comparative study.

BACKGROUND: The growing disparity between the rising demand for liver transplantation (LT) and the limited availability of donor organs has prompted a greater reliance on older liver grafts. Traditionally, utilizing livers from elderly donors has been associated with outcomes inferior to those achieved with grafts from younger donors. By accounting for additional risk factors, we hypothesize that the utilization of older liver grafts has a relatively minor impact on both patient survival and graft viability. AIM: To evaluate the impact of donor age on LT outcomes using multivariate analysis and comparing young and elderly donor groups. METHODS: In the period from April 2013 to December 2018, 656 adult liver transplants were performed at the University Hospital Merkur. Several multivariate Cox proportional hazards models were developed to independently assess the significance of donor age. Donor age was treated as a continuous variable. The approach involved univariate and multivariate analysis, including variable selection and assessment of interactions and transformations. Additionally, to exemplify the similarity of using young and old donor liver grafts, the group of 87 recipients of elderly donor liver grafts (≥ 75 years) was compared to a group of 124 recipients of young liver grafts (≤ 45 years) from the dataset. Survival rates of the two groups were estimated using the Kaplan-Meier method and the log-rank test was used to test the differences between groups. RESULTS: Using multivariate Cox analysis, we found no statistical significance in the role of donor age within the constructed models. Even when retained during the entire model development, the donor age's impact on survival remained insignificant and transformations and interactions yielded no substantial effects on survival. Consistent insignificance and low coefficient values suggest that donor age does not impact patient survival in our dataset. Notably, there was no statistical evidence that the five developed models did not adhere to the proportional hazards assumption. When comparing donor age groups, transplantation using elderly grafts showed similar early graft function, similar graft (P = 0.92), and patient survival rates (P = 0.86), and no significant difference in the incidence of postoperative complications. CONCLUSION: Our center's experience indicates that donor age does not play a significant role in patient survival, with elderly livers performing comparably to younger grafts when accounting for other risk factors.

Use of machine learning models for identification of predictors of survival and tumour recurrence in liver transplant recipients with hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is one of the leading indications for liver transplantation (LT) however, selection criteria remain controversial. We aimed to identify survival factors and predictors for tumour recurrence using machine learning (ML) methods. We also compared ML models to the Cox regression model. Methods: Thirty pretransplant donor and recipient general and tumour specific parameters were analysed from 170 patients who underwent orthotopic liver transplantation for HCC between March 2013 and December 2019 at the University Hospital Merkur, Zagreb. Survival rates were calculated using the Kaplan-Meier method and multivariate analysis was performed using the Cox proportional hazards regression model. Data was also processed through Coxnet (a regularized Cox regression model), Random Survival Forest (RSF), Survival Support Vector Machine (SVM) and Survival Gradient Boosting models, which included pre-processing, variable selection, imputation of missing data, training and cross-validation of the models. The cross-validated concordance index (CI) was used as an evaluation metric and to determine the best performing model. Results: Kaplan-Meier curves for 5-year survival time showed survival probability of 80% for recipient survival and 82% for graft survival. The 5-year HCC recurrence was observed in 19% of patients. The best predictive accuracy was observed in the RSF model with CI of 0.72, followed by the Survival SVM model (CI 0.70). Overall ML models outperform the Cox regression model with respect to their limitations. Random Forest analysis provided several relevant outcome predictors: alpha fetoprotein (AFP), donor C-reactive protein (CRP), recipient age and neutrophil to lymphocyte ratio (NLR). Cox multivariate analysis showed similarities with RSF models in identifying detrimental variables. Some variables such as donor age and number of transarterial chemoembolization treatments (TACE) were pointed out, but these were not influential in our RSF model. Conclusions: Using ML methods in addition to classical statistical analysis, it is possible to develop sufficient prognostic models, which, compared to established risk scores, could help us quantify survival probability and make changes in organ utilization.

Liver transplantation in hepatocellular carcinoma - should we perform downstaging?

AIM: To compare the long-term outcomes between liver transplant (LT) recipients with hepatocellular carcinoma (HCC) who were downstaged with transarterial-chemoembolization (TACE) to the Milan criteria (MC) and those initially meeting the MC. METHODS: This retrospective study enrolled 198 patients with HCC: 38 were downstaged and 160 patients initially met the MC. Post-LT survival and HCC recurrence-free survival were evaluated. We assessed the association of death and HCC recurrence with TACE, baseline (age, sex, disease etiology, Model of End-stage Liver Disease, tumor number and the sum of maximum tumor diameters, waiting time, alpha-fetoprotein level) and explant characteristics (tumor number and the sum of maximum tumor diameters, micro- and macrovascular invasion). RESULTS: The recipient survival rates one, three, and five years after LT were 88.2%, 80.1%, and 75.9%, respectively. HCC recurrence-free probabilities were 92.3%, 87.9%, and 85%, respectively. The outcomes were comparable between the groups. In multivariate analysis, the number of tumors on the explant, age, and tumor recurrence were independent risk factors for death. Only the sum of maximum tumor diameters on the explant was an independent risk factor for HCC recurrence. CONCLUSIONS: Patients successfully downstaged with TACE to the MC can achieve post-LT recipient and HCC recurrence-free survival comparable with patients initially within the MC. Good response to TACE as a criterion for LT may be a method of selecting patients with favorable biological characteristics.

THE COST OF KIDNEY TRANSPLANTATION AT THE MERKUR UNIVERSITY HOSPITAL, ZAGREB, CROATIA.

The aim was to determine the cost of hospitalization for a transplant procedure and identify the independent variables associated with the cost of transplantation. The investigation was designed as a retrospective single-center cohort study conducted at a tertiary university hospital transplant center in Zagreb, Croatia. The study included 219 consecutive kidney recipients transplanted during the 2007-2013 period at the Merkur University Hospital. There were 141 male and 78 female patients having undergone kidney transplantation during the study period. The majority of kidney transplants were from a deceased donor (n=179), while 40 were from a living donor. The mean cost of a transplantation was 86,140±42,240 HRK (11,460±5,600 €), ranging from 29,000 HRK (3,860 €) to 408,000 HRK (54,000 €). In the bivariate analysis, the variables associated with the cost of transplantation were the length of hospital stay, delayed graft function, death of the patient, graft loss, use of steroids, and death-censored graft loss. In the multivariate analysis, delayed graft function was the only statistically significant variable for the cost of transplantation. Since only delayed graft function had an impact on the cost of transplantation in this study, certain steps such as shortening of the cold ischemia time (better organization of organ transport), better education of family members for living donors, and higher percentage of patients on peritoneal dialysis should be taken to lower the percentage of delayed graft function.

Liver transplantation in patients with neuroendocrine tumors: a case series and literature review.

Neuroendocrine tumors (NET) are a rare and heterogeneous group of neoplasms with variable biological behavior. They frequently metastasize to the liver, requiring active, multimodality treatment. Surgical resection, possible in only a minority of cases, was until recently the only potentially curative option. For unresectable NET with liver metastases, liver transplantation (LT) emerged as a potential curative treatment due to relatively slow growth and indolent behavior of the metastases. In this case series with literature review, we retrospectively analyzed the characteristics of 12 highly selected patients with metastatic NET disease as an indication for LT treated in our center. We also summarized the proposed prognostic factors, and evaluated and compared the existing selection criteria. The main poor prognostic factors in our patients were high grade NET and primary tumor in the pancreas. Inconsistent liver transplantation outcome parameters make it difficult to standardize patient selection criteria. There is a need for further studies that would fully elucidate the curative potential of LT in patients diagnosed with NET.

Pre- and intraoperative predictors of acute kidney injury after liver transplantation.

BACKGROUND: Acute kidney injury (AKI) after liver transplantation (LT) is a frequent and multifactorial event related to increased morbidity and mortality. Risk factors for AKI after LT still need to be clarified. AIM: To identify the predictors of acute kidney injury after liver transplantation. METHODS: The frequency and pre- and intraoperative predictors of AKI within the first 7 d after LT were evaluated in adult liver transplant candidates in a single LT center in Croatia. AKI was defined according to the Kidney Disease: Improving Global Outcomes criteria. RESULTS: Out of 205 patients (mean age 57 ± 10 years; 73.7% males, 52.7% with alcohol-related liver disease) 93 (45.36%) developed AKI, and the majority of them (58.06%) had stage 1. Only 5.38% of patients required renal replacement therapy after LT. The majority of patients (82.8%) developed AKI within the first two days after the procedure. Multivariate logistic regression identified pre-LT body mass index (OR = 1.1, 95%CI: 1.05-1.24) and red blood cell transfusion (OR = 1.66, 95%CI: 1.09-2.53) as independent predictors of early post-LT AKI occurrence. 30-d survival after LT was significantly better for patients without AKI (P = 0.01). CONCLUSION: Early AKI after LT is a frequent event that negatively impacts short-term survival. The pathogenesis of AKI is multifactorial, but pre-LT BMI and intraoperative volume shifts are major contributors.

Adrenalectomy for Bilateral Metachronous Adrenal Recurrence of Hepatocellular Carcinoma After Liver Transplant: A Case Report.

Hepatocellular carcinoma is the fifth most common cancer in the world and the third leading cause of cancer-related death. It is currently one of the leading indications for liver transplant, with selected 5-year survival rates after liver transplant of about 70%. Despite excellent results of liver transplant for hepatocellular carcinoma, a number of patients develop metastases after transplant, and multifocal metastatic disease is the most frequent cause of death. In a large autopsy series of patients with hepatocellular carcinoma, adrenal glands were the third most common site of extrahepatic metastasis after lungs and bones. However, isolated metastatic disease in the adrenal glands is rare, and isolated metachronous bilateral metastasis is an even rarer occurrence. Only few reports have been published of metachronous bilateral metastasis of hepatocellular carinoma after liver transplant treated with bilateral adrenalectomy. We describe a case of a 56-year-old man who underwent liver transplant for hepatocellular carcinoma in a cirrhotic liver. Two years after liver tranplant, regular follow-up revealed metastatic disease in the left adrenal gland. Preoperative imaging showed no other metastasis, and he underwent an uneventful left adrenalectomy. A year after surgery, he presented with right flank pain and tenderness. Imaging showed hemorrhage and tumor involvement of the right adrenal gland, and he underwent right adrenalectomy. Two years after surgery, he is alive and well with no signs of disease recurrence. Apparently, in the absence of intrahepatic or other metastases, bilateral metachronous recurrence of hepatocellular carcinoma after liver tranplant can be a good surgical indication with acceptable long-term survival.

Constrictive pericarditis as a cause of refractory ascites after liver transplantation: A case report.

BACKGROUND: Refractory ascites is a rare complication following orthotopic liver transplantation (OLT). The broad spectrum of differential diagnosis often leads to delay in diagnosis. Therapy depends on recognition and treatment of the underlying cause. Constrictive pericarditis is a condition characterized by clinical signs of right-sided heart failure. In the advanced stages of the disease, hepatic congestion leads to formation of ascites. In patients after OLT, cardiac etiology of ascites is easily overlooked and it requires a high degree of clinical suspicion. CASE SUMMARY: We report a case of a 55-year-old man who presented with a refractory ascites three months after liver transplantation for alcoholic cirrhosis. Prior to transplantation the patient had a minimal amount of ascites. The transplant procedure and the early postoperative course were uneventful. Standard post-transplant work up failed to reveal any typical cause of refractory post-transplant ascites. The function of the graft was good. Apart from atrial fibrillation, cardiac status was normal. Eighteen months post transplantation the patient developed dyspnea and severe fatigue with peripheral edema. Ascites was still prominent. The presenting signs of right-sided heart failure were highly suggestive of cardiac etiology. Diagnostic paracentesis was suggestive of cardiac ascites, and further cardiac evaluation showed typical signs of constrictive pericarditis. Pericardiectomy was performed followed by complete resolution of ascites. On the follow-up the patient remained symptom-free with no signs of recurrent ascites and with normal function of the liver graft. CONCLUSION: Refractory ascites following liver transplantation is a rare complication with many possible causes. Broad differential diagnosis needs to be considered.

Liver re-transplantation for donor-derived neuroendocrine tumor: A case report.

BACKGROUND: Donor-origin cancer is a well-recognized but rare complication after liver transplantation (LT). The rise in the use of extended criteria donors due to the current shortage of organs increases the risk. Data on donor-origin neuroendocrine neoplasms (NENs) and the most appropriate treatment are scarce. Here, we report a case of a patient who developed a NEN confined to the liver after LT and was treated with liver re-transplantation (re-LT). CASE SUMMARY: A 49-year-old man with no other medical co-morbidities underwent LT in 2013 for alcoholic liver cirrhosis. The donor was a 73-year-old female with no known malignancies. Early after LT, a hypoechogenic (15 mm) lesion was detected in the left hepatic lobe on abdominal ultrasound. The lesion was stable for next 11 mo, when abdominal magnetic resonance identified two hypovascular lesions (20 and 11 mm) with atypical enhancement pattern. Follow-up abdominal ultrasound revealed no new lesions for the next 2.5 years, when magnetic resonance showed a progression in size and number of lesions, also confirmed by abdominal computed tomography. Liver biopsy proved a well-differentiated NEN. Genetic analysis of the NEN confirmed donor origin of the neoplasm. As NEN was confined to liver graft only, in 2018, the patient underwent his second LT. At 12 mo after re-LT the patient is well with no signs of NEN dissemination. CONCLUSION: The benefits of graft explantation should be weighed against the risks of re-LT and the likelihood of NEN dissemination beyond the graft.

Role of total pancreatectomy in the treatment of paraduodenal pancreatitis: A case report.

BACKGROUND: Paraduodenal pancreatitis (PP) is a rare form of chronic pancreatitis presenting with symptoms of duodenal obstruction. Conservative treatment is often unsuccessful and pancreaticoduodenectomy is the preferred surgical approach. A mini review of the outcomes of surgical therapy for PP shows that the results of pancreaticoduodenectomy are predominantly favorable. CASE SUMMARY: In our case report of PP, we describe an unusual course first presenting with the symptoms of chronic pancreatitis and a pseudocyst of the pancreatic tail. A pseudocystojejunostomy was performed and the late postoperative course was complicated with the symptoms of duodenal obstruction. At laparotomy, PP was found and the patient was treated with a total pancreatectomy. The postoperative course was uneventful and good weight gain with resolution of pain was demonstrated at follow up visits. CONCLUSION: Surgery is currently the optimal treatment option for PP. It is also the best diagnostic tool in distinguishing between pancreatitis and pancreatic adenocarcinoma.

The Intention-to-Treat Effect of Bridging Treatments in the Setting of Milan Criteria-In Patients Waiting for Liver Transplantation.

In patients with hepatocellular carcinoma (HCC) meeting the Milan criteria (MC), the benefit of locoregional therapies (LRTs) in the context of liver transplantation (LT) is still debated. Initial biases in the selection between treated and untreated patients have yielded conflicting reported results. The study aimed to identify, using a competing risk analysis, risk factors for HCC-dependent LT failure, defined as pretransplant tumor-related delisting or posttransplant recurrence. The study was registered at www.clinicaltrials.gov (identification number NCT03723304). In order to offset the initial limitations of the investigated population, an inverse probability of treatment weighting (IPTW) analysis was used: 1083 MC-in patients (no LRT = 182; LRT = 901) were balanced using 8 variables: age, sex, Model for End-Stage Liver Disease (MELD) value, hepatitis C virus status, hepatitis B virus status, largest lesion diameter, number of nodules, and alpha-fetoprotein (AFP). All the covariates were available at the first referral. After the IPTW, a pseudo-population of 2019 patients listed for LT was analyzed, comparing 2 homogeneous groups of untreated (n = 1077) and LRT-treated (n = 942) patients. Tumor progression after LRT was the most important independent risk factor for HCC-dependent failure (subhazard ratio [SHR], 5.62; P < 0.001). Other independent risk factors were major tumor diameter, AFP, MELD, patient age, male sex, and period of wait-list registration. One single LRT was protective compared with no treatment (SHR, 0.51; P < 0.001). The positive effect was still observed when 2-3 treatments were performed (SHR, 0.66; P = 0.02), but it was lost in the case of ≥4 LRTs (SHR, 0.80; P = 0.27). In conclusion, for MC-in patients, up to 3 LRTs are beneficial for success in intention-to-treat LT patients, with a 49% to 34% reduction in failure risk compared with untreated patients. This benefit is lost if more LRTs are required. A poor response to LRT is associated with a higher risk for HCC-dependent transplant failure.

Simultaneous Orthotopic Liver Transplantation With Abdominal Aortic Aneurysm Repair: A Case Report.

The simultaneous occurrence of an abdominal aortic aneurysm and liver cirrhosis needing surgical treatment is extremely rare. There is still controversy regarding the timing of abdominal aortic aneurysm repair and liver transplantation and regarding optimal treatment of the aneurysm. Here, we describe a 70-year-old white male patient who presented with end-stage liver disease secondary to chronic hepatitis C with a solitary hepatocellular carcinoma measuring 5.5 cm in diameter in the right liver lobe. A pretransplant work-up resulted in discovery of a 6.7-cm abdominal aortic aneurysm. The decision was made to perform orthotopic liver transplantation with simultaneous aneurysm repair. The patient was initially explored through a median laparotomy. The liver transplant was performed first with the graft prepared on the back table using a standard procedure. The liver graft was transplanted using a "piggy-back" technique with end-to-side caval and end-to-end portal vein anastomosis. The arterial anastomosis was performed with an end-to-end anastomosis between the donor's proper hepatic artery and the recipient's common hepatic artery. The bile duct anastomosis was performed with an end-to-end anastomosis. A midline incision was extended to the pubis. After proximal and distal vascular control of the infrarenal aorta, resection of the abdominal aortic aneurysm was performed followed by reconstruction with an InterVascular 22-mm prosthesis using 3.0 Prolene in a running fashion. Eight days after surgery, the patient was discharged and remained well during the 2-year follow-up. Although rare, in a patient with end-stage liver disease and abdominal aortic aneurysm, a simultaneous liver transplantation and aneurysm repair procedure represents the safest treatment solution.

Right hepatectomy due to portal vein thrombosis in vasculobiliary injury following laparoscopic cholecystectomy: a case report.

INTRODUCTION: Vasculobiliary injury composed of bile duct, portal vein and hepatic artery injury is a rare, but the most severe, complication after cholecystectomy that may require hepatectomy or even urgent liver transplantation. CASE PRESENTATION: We present a case of a 36-year-old Caucasian woman with a biliary sepsis and a large right liver lobe abscess due to an extreme vasculobiliary injury after laparoscopic cholecystectomy. Bismuth type IV biliary duct injury, portal vein thrombosis and injury of right hepatic artery were identified, resulting in life-threatening septic episodes. Right hepatectomy with Roux-en-Y hepaticojejunostomy and reconstruction of her portal vein with a vein allograft were performed. She fully recovered and remained well during 3 years of follow-up. CONCLUSIONS: Although rare, the impact of vasculobiliary injuries after cholecystectomy highlights the need for constant alertness and prompt management in order to minimize the risk of the routine operative procedure. Hepatectomy with biliary and vascular reconstruction should be considered early in the management of vasculobiliary injury to avoid the development of life-threatening consequences.

Effect of mycophenolate mofetil on progression of interstitial fibrosis and tubular atrophy after kidney transplantation: a retrospective study.

OBJECTIVES: Chronic transplant dysfunction after kidney transplantation is a major reason of kidney graft loss and is caused by immunological and non-immunological factors. There is evidence that mycophenolate mofetil (MMF) may exert a positive effect on renal damage in addition to immunosuppression, by its direct antifibrotic properties. The aim of our study was to retrospectively investigate the role of MMF doses on progression of chronic allograft dysfunction and fibrosis and tubular atrophy (IF/TA). SETTING: Retrospective, cohort study. PARTICIPANTS: Patients with kidney transplant in a tertiary care institution. This is a retrospective cohort study that included 79 patients with kidney and kidney-pancreas transplantation. Immunosuppression consisted of anti-interleukin 2 antibody induction, MMF, a calcineurin inhibitor±steroids. PRIMARY OUTCOME MEASURES: An association of average MMF doses over 1 year post-transplant with progression of interstitial fibrosis (Δci), tubular atrophy (Δct) and estimated-creatinine clearance (eCrcl) at 1 year post-transplant was evaluated using univariate and multivariate analyses. RESULTS: A higher average MMF dose was significantly independently associated with better eCrcl at 1 year post-transplant (b=0.21±0.1, p=0.04). In multiple regression analysis lower Δci (b=-0.2±0.09, p=0.05) and Δct (b=-0.29±0.1, p=0.02) were independently associated with a greater average MMF dose. There was no correlation between average MMF doses and incidence of acute rejection (p=0.68). CONCLUSIONS: A higher average MMF dose over 1 year is associated with better renal function and slower progression of IF/TA, at least partly independent of its immunosuppressive effects.

Successful management of unsuspected retroperitoneal paraganglioma via the use of combined epidural and general anesthesia: a case report.

INTRODUCTION: Similar to pheochromocytomas, paragangliomas can secrete catecholamines, although they are usually non-functional and clinical presentation is non-specific. We present a case of accidental, intra-operatively diagnosed neuroendocrine-active sympathetic paraganglioma, which was suspected and confirmed during elective retroperitoneal tumor removal. CASE PRESENTATION: A 25-year-old Caucasian Croatian man, American Society of Anesthesiologists status 1, underwent elective surgery for retroperitoneal tumor removal. The tumor had been discovered by chance during a routine examination and was suspected to be a sarcoma. Our patient had no history of previous medical conditions nor did he have symptoms characteristic of a neuroendocrine secreting tumor. The results of ultrasound and magnetic resonance imaging studies showed a large, well demarcated retroperitoneal tumor mass in his upper abdomen localized between the aorta and vena cava, measuring approximately 9×6×4.5cm. In the operating room an epidural catheter was inserted at the T7 to T8 level prior to induction of general anesthesia. Epidural analgesia was maintained by an infusion pump with local anesthetic and opiate mixture. During the surgical excision of the tumor, hemodynamic changes occurred, with hypertension (205/110mmHg) and tachycardia (up to 120 beats/minute). In spite of the fact that the surgical field of work did not include adrenal glands whose direct manipulation could explain this occurrence, there was a high degree of suspicion for the presence of a neurosecreting tumor. His clinical symptoms were relieved after administration of urapidil, esmolol and magnesium sulfate. After tumor excision, our patient developed severe hypotension. Hemodynamic stability was reinstated with aggressive volume replacement, with crystalloids and colloids, vasopressors and hydrocortisone. His post-operative course was unremarkable and on the eighth post-operative day our patient was discharged from hospital, with no consequences or symptoms on follow-up two years after surgery. CONCLUSIONS: Our patient's case emphasizes the need to consider the presence of extra-adrenal paragangliomas in the differential diagnosis of retroperitoneal tumors, despite their rare occurrence. In our patient's case, invasive hemodynamic monitoring during combined general anesthesia and epidural analgesia and early recognition of catechol-induced symptoms raised suspicion of the existence of a paraganglioma, and this led to an adequate therapeutic approach and favorable outcome of the surgery. Pre-operative recognition of paragangliomas could lead to better pre-operative preparation, but even high clinical suspicion in undiagnosed forms during surgery and the availability of rapid and short-acting vasodilatators, α-blockers and ß-blockers might favor good outcome.

[Post-transplant lymphoproliferative disease in liver transplant recipients--Merkur University Hospital single center experience]. / Post-transplantacijska limfoproliferativna bolest u bolesnika s transplantacijom jetre - iskustvo KB Merkur.

Post-transplant lymphoproliferative disorder (PTLD) is an increasingly recognized condition as the number of solid organ and bone marrow transplant recipients increases. It can be a life threatening fulminant disorder and affects approximately 8% of solid organ transplant recipients. Epstein-Barr virus (EBV) is closely involved in the pathogenesis of PTLD and the majority of PTLD cases arise in response to primary infection with EBV or to re-activation of previously acquired EBV. The principal risk factors underlying the development of PTLD are the degree of overall immunosuppression and EBV serostatus of the recipient. The most commonly used pathologic classification of PTLD is the World Health Organization classification, which divides PTLD into three categories: early lesions, polymorphic PTLD, and monomorphic PTLD. Early lesions are characterized by reactive plasmacytic hyperplasia. Polymorphic PTLD may be either polyclonal or monoclonal and is characterized by destruction of the underlying lymphoid architecture, necrosis, and nuclear atypia. In monomorphic PTLD, the majority of cases (>80%) arise from B cells, similar to non-Hodgkin's lymphoma in immunocompetent hosts. The most common subtype is diffuse large B-cell lymphoma, but Burkitt's/Burkitt's-like lymphoma and plasma cell myeloma are also seen. Rarely T-cell variants occur, which include peripheral T-cell lymphomas and, rarely, other uncommon types, including gamma/delta T-cell lymphoma and T-natural killer (NK) cell varieties. Hodgkin's disease-like lymphoma is very unusual. An accurate diagnosis of PTLD requires a high index of suspicion, since the disorder may present subtly and/or extranodally. Radiologic evidence of a mass or the presence of elevated serum markers (such as increased LDH levels) are suggestive of PTLD, with positive finding on ultrasonography, computed tomography, magnetic resonance and/or positron emission tomography scanning (possibly indicating metabolically active areas) also favoring the diagnosis. The management of PTLD poses a major therapeutic challenge and although there is reasonable agreement about the overall principles of treatment, there is still considerable controversy about the optimal treatment of individual patients. EBV-related PTLDs are a significant cause of mortality in patients undergoing orthotopic liver transplantation with the observed mortality rate of up to 50%. This paper presents the experience acquired at Merkur University Hospital in the diagnosis and treatment of patients with liver transplantation and PTLD.