Total Hip Arthroplasty Outcomes before or after Renal Transplant: A Retrospective Large Cohort Analysis.

Background: While it is known that patients with end-stage renal disease (ESRD) are at an increased risk of complications following total hip arthroplasty (THA), there is a gap in the literature in comparing patients with ESRD to patients who undergo renal transplant (RT) before or after THA. This study is to address this gap by analyzing outcomes of THA in ESRD patients, RT patients, and RT candidates. Methods: Using the PearlDiver Mariner database, ESRD patients, RT patients, and RT candidates undergoing primary THA were identified and compared. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. Ninety-day emergency department (ED) visits and inpatient readmission were also documented. Results: A total of 7,868 patients were included: 5,092 had ESRD, 2,520 had RT before THA, and 256 were candidates for RT. Compared to patients with ESRD, RT patients demonstrated lower rates of medical complications such as pneumonia (3.61% vs. 5.99%, p = 0.039) and transfusion (4.60% vs. 7.66%, p < 0.001). Additionally, RT patients displayed decreased rates of surgical complications, including wound complications (2.70% vs. 4.22%, p = 0.001), periprosthetic joint infection (PJI) at 1 year (2.30% vs. 4.81%, p < 0.001) and 2 years (2.58% vs. 5.42%, p < 0.001), and aseptic loosening at 2 years (0.79% vs. 1.43%, p = 0.006). Similarly, when compared to RT candidates, RT patients demonstrated a lower incidence of postoperative complications, including 1-year PJI (2.30% vs. 5.08%, p = 0.013), 2-year PJI (2.58% vs. 5.08%, p = 0.028), 1-year aseptic loosening (0.56% vs. 2.73%, p < 0.001), and 2-year aseptic loosening (0.79% vs. 2.73%, p = 0.005). RT patients also had lower rates of ED visits and hospital readmissions. Conclusions: Compared to ESRD patients and RT candidates, patients with RT have a significantly lower likelihood of medical complications, PJI, aseptic hardware loosening, ED visits, and hospital readmission. Patients with ESRD on the RT waiting list should delay THA until after RT surgery. For those not eligible for RT, it is vital to take extra precautions to reduce the risk of complications.

Metastatic pulmonary calcification in a renal transplant recipient.

Metastatic pulmonary calcification (MPC) is a metabolic disorder characterized by an ectopic deposition of calcium in the lung parenchyma, prevalent in patients with chronic kidney disease. A combination of parenchymal lung abnormalities on high resolution chest computed tomography (CT) and pulmonary radiotracer uptake in 99mTc-methyl diphosphate (MDP) bone scintigraphy can establish diagnosis of MPC. We herein present a case of MPC with documented stability of chest CT abnormalities after renal transplant. We also describe novel findings of diffuse pulmonary uptake of 18F-sodium fluoride, a calcium-avid radiotracer, in positron emission tomography (PET)/CT performed in the same patient.

Percutaneous nephrolithotomy for adult renal transplant de novo graft lithiasis: a single center analysis and systematic review of the literature.

INTRODUCTION/OBJECTIVE: Graft stones in renal transplant recipients pose a unique challenge, finding effective interventions to ensure optimal graft function and patient well-being. Various methods of stone clearance have been described for graft stones, including percutaneous nephrolithotomy (PCNL). While PCNL is a promising approach for managing graft stones, specific outcomes and associated characteristics for this approach have not been comprehensively evaluated before. This study aims to evaluate the safety and efficacy of the use of PCNL as the primary intervention of graft stones by assessing stone-free rates (SFR), treatment impact on graft function, and perioperative complications. METHODS: A retrospective clinical audit was performed for all transplants performed in a single center from 2007 to 2022, which included all graft lithiasis patients who were treated with PCNL. Both perioperative parameters and post-operative outcomes were collected. In addition, a systematic review including articles from MEDLINE, Embase, Web of Science yielded 18 full-text articles published between 1/1/2000 and 15/11/2023. The results pertaining to patients who underwent PCNLs for graft stones were cross-referenced and thoroughly evaluated. The review encompassed a comprehensive analysis of clinical data, postoperative outcomes, and procedural details. The protocol for the systematic review was prospectively registered on PROSPERO (CRD42023486825). RESULTS: In our center, 6 graft lithiasis patients were treated with PCNL. The initial SFR was 83.3%. SFR at 3 months and 1 year were both 100.0%. SFR at 3 years was 66.7%. Other centers reported initial SFR of 82.6-100.0% (interquartile range). SFR at 3 months, 1 year, 3 years was not well reported across the included studies. Incidence of graft lithiasis ranged from 0.44%-2.41%. Most common presentations at diagnosis were oliguria/anuria/acute kidney injury and asymptomatic. Reported complications included blood loss, transient hematuria, high urine output, sepsis, and damage to surrounding structures. The most commonly reported metabolic abnormalities in transplant lithiasis patients included hyperuricemia and hyperparathyroidism. CONCLUSION: PCNL is a practical and efficient choice for addressing graft lithiasis, demonstrating excellent stone clearance and minimal perioperative complications. These findings show the importance of PCNL as a primary intervention in this complex patient population.

Assessment of the herpes zoster risk among renal transplant recipients administered the influenza vaccine.

BACKGROUND: Reactivation of the latent varicella-zoster virus can cause herpes zoster (HZ) infection, and renal transplant recipients undergoing immunosuppressive therapy are particularly susceptible to this condition. This study aims to evaluate the potential increase in HZ incidence following influenza vaccination among this specific patient population. METHODS: This study was a population-based, retrospective, self-controlled case series. Data were retrieved from Taiwan's National Health Insurance Research Database spanning the years 2008 to 2017. Patients diagnosed with HZ within a 6-month period before and after receiving the influenza vaccine were eligible for inclusion. Two distinct time intervals were defined for analysis: the initial 15 days and 30 days following vaccination were categorized as risk intervals, while all other periods served as control intervals. Incidence rate ratios (IRRs) were computed to compare HZ incidence during the risk intervals with that during the control intervals. RESULTS: This study encompassed a cohort of 4,222 renal transplant recipients who had received the influenza vaccine. Among this group, 67 recipients were subsequently diagnosed with HZ. The IRR during both the initial 15 days (IRR = 0.63; 95 % CI, 0.23-1.89) and the first 30 days (IRR = 1.50; 95 % CI, 0.71-3.16) following influenza vaccination did not demonstrate a statistically significant increase when compared to the post-exposure observation times. Comparable results were also observed when comparing these IRR values to the pre-exposure observation times. The subgroup analysis, stratified by age, sex, and underlying medical conditions (including cancer and autoimmune diseases), revealed that the IRRs did not exhibit statistically significant differences. CONCLUSIONS: No significant association between the influenza vaccine and an elevated risk of HZ was detected. The administration of annual influenza vaccines appears to be a reasonable practice for renal transplant recipients.

Contrast-enhanced ultrasound of renal masses in the pre-transplant setting: literature review with case highlights.

With the rising incidence of chronic kidney disease worldwide, an increasing number of patients are expected to require renal transplantation, which remains the definitive treatment of end stage renal disease. Medical imaging, primarily ultrasonography and contrast-enhanced CT and/or MRI, plays a large role in pre-transplantation assessment, especially in the characterization of lesions within the native kidneys. However, patients with CKD/ESRD often have relative contraindications to CT- and MR-contrast agents, limiting their utilization within this patient population. Contrast-enhanced ultrasound (CEUS), which combines the high temporal and spatial resolution of ultrasonography with intravascular microbubble contrast agents, provides a promising alternative. This review aims to familiarize the reader with the literature regarding the use of CEUS in the evaluation of cystic and solid renal lesions and provide case examples of its use at our institution in the pre-transplant setting.

Immune checkpoint inhibitors and renal toxicity.

Immune checkpoint inhibitors (ICIs) have transformed the management of a broad spectrum of cancers as metastatic melanoma, non-small lung cancer or renal cell carcinoma. These humanized monoclonal antibodies target immune-regulatory receptors expressed on T lymphocytes, antigen presenting cells and tumor cells and induce an immunological anti-tumor response. If on the one hand these molecules have led to considerable improvement in survival outcomes, on the other hand these therapies can be associated with immune-related adverse effects (irAEs). While these side effects have become well known, the best diagnostic and therapeutic approaches are still under investigation. The authors discuss pathophysiology, clinical presentation and histological features of ICIs renal toxicity. Furthermore, we focus on kidney transplant (KT) recipients, including the therapeutic adaptation approach to immunosuppression and the risk of rejection.

Trichosporon asahii co-infection with Pneumocystis jiroveci in a renal transplant patient.

Trichosporon asahii is considered an opportunistic pathogen, capable of causing superficial infections in humans and invasive deep-seated infections in immunocompromised hosts. Pneumocystis jirovecii can cause life-threatening pneumonia in immunosuppressed patients. Both Trichosporon and Pneumocystis jirovecii are highly lethal in immunocompromised individuals. Here we present a case of invasive Trichosporon asahii co-infection with Pneumocystis jiroveci in a renal transplant patient.

Assessment of Tumor Markers in Renal Transplant Recipients.

Background/Aim: Malignant tumors are diagnosed using various methods, including diagnostic imaging methods. The measurement of tumor markers is commonly used because of its noninvasiveness and convenience. Furthermore, it is known that the excretion and metabolism of some tumor markers are affected by impaired renal function. In the present study, we investigated the effect of improved renal function on pre-and post-transplantation changes in tumor marker levels [carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), and prostate-specific antigen (PSA)] in renal transplant recipients. Patients and Methods: A total of 116 renal transplant recipients, who had not been diagnosed with malignancies between January 2012 and December 2019, were included, and tumor markers were investigated. Results: CEA showed a significant decrease after kidney transplantation, regardless of the dialysis type (3.6→2.6 ng/ml, p<0.001), while other tumor markers showed a significant increase (AFP: 3.6→3.7 ng/ml; CA19-9: 16.2→19.5 U/ml; PSA: 0.95→1.05 ng/ml; all p<0.05). Pre- and postoperative eGFR ratios and postoperative liver function were identified as factors influencing the postoperative CEA and CA19-9 values, while PSA was influenced by the duration of dialysis. No statistically significant factors were found for AFP levels. Conclusion: Caution should be exercised when investigating tumor markers in patients with renal dysfunction, as tumor marker levels may vary depending on the pathophysiology of each patient.

Prevalence of Musculoskeletal and Metabolic Disorders in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis.

Introduction: Musculoskeletal disorders could be associated with metabolic disorders that are common after kidney transplantation, which could reduce the quality of life of patients. The aim of this study was to assess the prevalence of both musculoskeletal and metabolic disorders in kidney transplant patients. Methods: MEDLINE, CINAHL, Cochrane Library, EMBASE and Web of Science were searched from their inception up to June 2023. DerSimonian and Laird random-effects method was used to calculate pooled prevalence estimates and their 95% confidence intervals (CIs). Results: 21,879 kidney transplant recipients from 38 studies were analysed. The overall proportion of kidney transplant patients with musculoskeletal disorders was 27.2% (95% CI: 18.4-36.0), with low muscle strength (64.5%; 95% CI: 43.1-81.3) being the most common disorder. Otherwise, the overall proportion of kidney transplant patients with metabolic disorders was 37.6% (95% CI: 21.9-53.2), with hypovitaminosis D (81.8%; 95% CI: 67.2-90.8) being the most prevalent disorder. Conclusion: The most common musculoskeletal disorders were low muscle strength, femoral osteopenia, and low muscle mass. Hypovitaminosis D, hyperparathyroidism, and hyperuricemia were also the most common metabolic disorders. These disorders could be associated with poorer quality of life in kidney transplant recipients. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier [CRD42023449171].

Robotic-Assisted Management of Ureteral Complications in Post-Renal Transplant Patients: A Case Series and Literature Review.

Introduction: Urologic complications are thought to be the most common surgical complication of renal transplantation. Ureteral pathology, including stenosis, urine leak, and vesicoureteral reflux, predominates. Although endourologic and interventional radiological management may be utilized, failure rates remain relatively high and surgical reconstruction remains the definitive management. Robotic ureteral reconstruction has been demonstrated to provide patient benefit in nontransplant populations, but the literature on transplant reconstruction is very limited. This study reports an additional series of patients with a focus on surgical technique, as well as reviews the available evidence for robotic reconstruction for post-transplant ureteral complications. Methods: All institutional patients undergoing robotic-assisted reconstruction for post-transplant ureteral complications for the years 2019-2022 were included. Intra- and postoperative variables, patient demographics, and follow-up data were obtained retrospectively from parsing of patient records. Statistics were tabulated descriptively. Results: Eleven patients underwent ureteral reconstruction. Of the 11, 9 (81%) were male with a mean age of 51.9 years (16-70) and BMI of 33.8 (24.3-49.1). The most common (10/11) indication for reconstruction was stricture; the most common (10/11) technique used was Lich-Gregoir reimplantation. Mean operative time was 288 minutes (143-500). There were no intra- or immediate postoperative complications. Median length of stay was 2 days (1-22). There were two incidences of mortality at 2 and 5 months postoperatively unrelated to surgery. There were four readmissions within 30 days, three for urinary tract infection (UTI) and one for a pelvic abscess which required washout. The remainder of the cohort has been followed for a mean of 14.6 months (6-41) without any incidences of graft loss or recurrence of ureteral pathology. Conclusions: Robotic-assisted ureteral reconstruction is a technically challenging but highly feasible technique that may provide the benefits of minimally invasive surgery while still allowing definitive reconstruction. Centers with extensive robotic capabilities should consider the technique.

Lateral sacral artery aneurysm.

A rare case of aneurysm of the lateral sacral artery is reported. This 46-year-old female presented with complaints of bowel and bladder incontinence and decreased perianal sensation for the past 15 months. She underwent laminectomy and diskectomy for the diagnosis of a prolapsed disk at peripheral hospital where the surgeon was confronted with a severe and unexpected hemorrhage, and surgery was aborted without effective treatment. Prior medical history includes hypertensive kidney disease with a renal transplant eight years ago. Magnetic resonance imaging and angiographic findings were suggestive of a lateral sacral artery aneurysm. Patient with a history of renal transplant and presenting with cauda equina require a more thorough assessment, and a differential of lateral sacral artery aneurysm should always be kept in mind. Our purpose is to report the pre-operative features of the lateral sacral artery aneurysm and its treatment modalities.

Clinical Features and Prognostic Predictors in Patients with Renal Transplant Complicated by SARS-CoV-2 Infection, a Retrospective Single-Center Study.

Background: This study examines the clinical outcomes and prognostic factors of COVID-19 in renal transplant recipients. Given their immunosuppressed status, these patients are at higher risk of severe complications from COVID-19. The study aims to provide healthcare professionals with critical insights for diagnosing and managing this vulnerable population. Patients and methods: This retrospective cohort study included adult renal transplant recipients diagnosed with COVID-19. Data on demographics, medical history, laboratory results, and patient outcomes were analyzed to identify clinical characteristics and prognostic factors. Results: This study included 115 renal transplant recipients with COVID-19, predominantly male, with a mortality rate of 10.4% (12 deaths). The overall vaccination rate was 20%. Univariate analysis showed significant differences between survivors and non-survivors in initial serum creatinine levels, and percentages of neutrophils, monocytes, and lymphocytes, along with CRP levels on day 3. Additionally, CRP levels, hemoglobin, and platelet counts on day 7 also differed significantly. Multivariate analysis identified CRP levels on days 3 and 7, day 7 hemoglobin and platelet counts, and concurrent bacterial infections as independent risk factors for mortality. Conclusion: Elevated CRP levels, renal impairment, and bacterial co-infections play a significant role in the outcomes of COVID-19 in kidney transplant recipients. This study highlights the importance of monitoring these factors for early identification and management of high-risk patients.

Improving prediction of tacrolimus concentration using a combination of population pharmacokinetic modeling and machine learning in chinese renal transplant recipients.

Aims: The population pharmacokinetic (PPK) model-based machine learning (ML) approach offers a novel perspective on individual concentration prediction. This study aimed to establish a PPK-based ML model for predicting tacrolimus (TAC) concentrations in Chinese renal transplant recipients. Methods: Conventional TAC monitoring data from 127 Chinese renal transplant patients were divided into training (80%) and testing (20%) datasets. A PPK model was developed using the training group data. ML models were then established based on individual pharmacokinetic data derived from the PPK basic model. The prediction performances of the PPK-based ML model and Bayesian forecasting approach were compared using data from the test group. Results: The final PPK model, incorporating hematocrit and CYP3A5 genotypes as covariates, was successfully established. Individual predictions of TAC using the PPK basic model, postoperative date, CYP3A5 genotype, and hematocrit showed improved rankings in ML model construction. XGBoost, based on the TAC PPK, exhibited the best prediction performance. Conclusion: The PPK-based machine learning approach emerges as a superior option for predicting TAC concentrations in Chinese renal transplant recipients.

Late pregnancy in women with renal transplants: A multidisciplinary guide.

Kidney transplant recipients are at risk of complications in late pregnancy, with increased rates of pre-eclampsia, intrauterine growth restriction and preterm birth. It is recommended that these women receive more intensive monitoring after 20 weeks' gestation, ideally provided by a multidisciplinary team in a tertiary centre. This review focuses on the management of late pregnancy in kidney transplant recipients, from the perspective of different members of the multidisciplinary team. This includes evidence and guidance to inform the nephrologist, obstetrician, obstetric anaesthetist, transplant surgeon, midwife, and a summary of the woman's perspective. The review outlines a late pregnancy and early postnatal care pathway as a common algorithm to be used by the whole multidisciplinary team.

Implant Survival in Renal-Transplanted Patients: A Prospective Long-Term Study.

The present study aims to assess the feasibility of implant rehabilitation in kidney-transplanted patients. Patients with kidney transplantation included in periodontal supportive care and at least one year of dialysis with mono- or partial edentulism were eligible for this study. Histomorphometric evaluation of the harvested bone was matched with radiological bone assessment. Implant stability was also monitored with resonance frequency analysis and insertion torque value. Fixed cemented prostheses have been delivered after conventional loading protocol. Supportive periodontal therapy has been administered. Eleven patients (9 males and 2 females) were included. The mean age was 58.1 ± 9.9 years. A total of 17 implants were inserted and analyzed. Mean ITV was 39.3 ± 23.8 Ncm. The mean primary stability (implant stability quotient) at T0 was 71.7 ± 10.5, whereas the mean secondary stability at T1 was 73.0 ± 7.3. The minimum follow-up was 62 months, with a maximum of 84 months (7 years) reached by 4 patients. Fourteen out of 15 implants were in function at a 5-year follow-up (survival rate: 93.3%). Two implants showed peri-implantitis. Seventeen bone samples were collected (13 in the mandible and 4 in the maxilla). The mean percentage of marrow spaces and lamellar bone was 41.6% and 58.4%, respectively. Class 3, according to Misch classification, was found as the mean value of radiological bone density. It can be concluded that implant-supported rehabilitation in kidney-transplanted patients is possible. Adequate periodontal maintenance allows implant rehabilitation in kidney-transplanted patients with long-term sufficient survival rates.

Diagnosing and Managing Urinary Tract Infections in Kidney Transplant Recipients.

In the article, the authors review antibiotic treatment options for both acute uncomplicated UTI and complicated UTI. In addition, they review alternative regimens which are needed in the setting of drug-resistant pathogens including vancomycin-resistant Enterococcus, -extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales, and carbapenem-resistant Pseudomonas, which are encountered with more frequency.

Management strategies for common viral infections in pediatric renal transplant recipients.

Viral infections have been considered as a major cause of morbidity and mortality after kidney transplantation in pediatric cohort. Children are at high risk of acquiring virus-related complications due to immunological immaturity and the enhanced alloreactivity risk that led to maintenance of high immunosuppressive regimes. Hence, prevention, early detection, and prompt treatment of such infe ctions are of paramount importance. Among all viral infections, herpes viruses (herpes simplex virus, varicella zoster virus, Epstein-Barr virus, cytomegalovirus), hepatitis B and C viruses, BK polyomavirus, and respiratory viruses (respiratory syncytial virus, parainfluenza virus, influenza virus and adenovirus) are common in kidney transplant recipients. These viruses can cause systemic disease or allograft dysfunction affecting the clinical outcome. Recent advances in tech nology and antiviral therapy have improved management strategies in screening, monitoring, adoption of prophylactic or preemptive therapy and precise trea tment in the immunocompromised host, with significant impact on the outcome. This review discusses the etiology, screening and monitoring, diagnosis, pre vention, and treatment of common viral infections in pediatric renal transplant recipients.

Comparison of skin cancer risk between renal transplant recipients and patients with glomerular diseases in rural Queensland.

INTROUDCTION: There is increased risk of skin cancer in patients with gloermular disease or those with renal transplant. OBJECTIVES: To compare the risk of skin cancer between kidney recipients (KTRs) and patients with glomerular disease (GD). DESIGN: The cohort comprised patients with KTRs (n = 61) and GD (n = 51) in Central and Central West Queensland, Australia. A quantitative cohort study was undertaken to study the risk of skin cancer in rural communities between two subgroups of patients with kidney diseases in relationship to immunosuppression. Statistical analyses of the differences in incidence of skin cancers between the two groups were done by chi-square test, Fisher's exact test, independent t-test and McNemar's test. FINDINGS: KTRs with non-melanoma skin carcinoma (NMSC) increased significantly after treatment with immunosuppressants (pre-transplantation, n = 11 [18.0%], post-transplantation, n = 28 [45.9%]; p < 0.001). There were no differences in number of patients with NMSC observed in the GD group (pre-diagnosis, n = 6 [11.8%], post-diagnosis, n = 7 [13.7%]; p = 1.000). Compared to the risks at 1 year post-immunosuppressants, the incidence of NMSC of KTRs increased significantly at 3 years (20.3% vs. 35.4%, p < 0.001) and 5 years (20.3% vs. 62.2%, p < 0.001) post-immunosuppressants, whereas the increased incidence of NMSC was observed only at 5 years (2.1% vs. 11.8%, p = 0.012) in the GD cohort. The mean cumulative number of NMSC in KTRs increased significantly at 3 years (p = 0.011), and 5 years (p = 0.001) post-immunosuppressants, compared to the risks at 1 year post-immunosuppressants, however, no differences were noted in the GD cohort. DISCUSSION: Immunosuppressants increased the risk of NMSC in KTRs. The increased risk is likely dependent on the intensity and duration of immunosuppressants. CONCLUSION: In patients with a high risk of NMSC, reducing skin cancer risk should be considered in conjunction with the optimisation of treatment.

Imaging features of perinephric myxoid pseudotumors of fat.

OBJECTIVE: Retrospectively evaluate multimodality imaging features of perinephric myxoid pseudotumor of fat (PMPTF). METHODS: Institutional cases of PMPTF with CT, MRI and/or ultrasound evaluation from 1/1/2020 to 9/1/2023 were retrospectively reviewed. Patient demographics and clinical history were reviewed, and imaging features recorded. RESULTS: 14 patients with pathologically-proven PMPTF were identified (11 M, 3 F; mean age 66.7 ± 17.0 years; range 40-87 years). Three patients (18%) had bilateral lesions; a total of 17 PMPTFs were reviewed. 15/17 (88%) were biopsy-proven; two cases were diagnosed by imaging only in patients with a contralateral biopsy-proven PMPTF. All evaluable specimens were negative for MDM2 amplification. 11/17 (65%) occurred in patients with renal disease, including 4/17 (24%) in patients with renal transplant. 100% (17/17) had CT, 11/17 (65%) MRI, and 6/17 (35%) ultrasound. The mean largest lesion dimension was 10.9 ± 4.6 cm (range 4.3-17.0 cm). Of cases involving native kidneys, 7/13 (54%) presented as multifocal perinephric masses and 5/13 (38%) as a solitary perinephric mass. All four transplant cases presented as infiltrative-appearing masses involving the renal sinus with lesser perinephric involvement. 14/17 (82%) lesions contained macroscopic fat on CT and MRI and 3/17 (18%) showed no macroscopic fat, all involving renal transplants. All cases with MRI demonstrated T2 hyperintensity with signal dropout on opposed-phase imaging. 11/13 (85%) PMPTF showed no or equivocal CT enhancement. Enhancement was better seen on MRI in all cases evaluated by both CT and MRI. Of the six PMPTFs imaged by ultrasound, four (67%) were heterogeneously hypoechoic and two (33%) had mixed regions of hypo-, iso- and hyperechogenicity relative to adjacent renal parenchyma. CONCLUSIONS: PMPTF is a rare, benign, and underrecognized lesion that may mimic malignancy, particularly retroperitoneal well-differentiated liposarcoma. The imaging features of this unusual pseudosarcoma differ in native and transplanted kidneys. Improved awareness of this entity will facilitate appropriate patient management and avoid unnecessary intervention.