Percutaneous kidney biopsies in children: a 24-year review in a tertiary center in northern Portugal / Biópsias renais percutâneas em crianças: uma revisão de 24 anos em um centro terciário no norte de Portugal

Introduction: Percutaneous kidney biopsy (KB) is crucial to the diagnosis and management of several renal pathologies. National data on native KB in pediatric patients are scarce. We aimed to review the demographic and clinical characteristics and histopathological patterns in children who underwent native percutaneous KB over 24 years. Methods: Retrospective observational study of patients undergoing native percutaneous KB in a pediatric nephrology unit between 1998 and 2021, comparing 3 periods: period 1 (1998-2005), period 2 (2006-2013), and period 3 (2014-2021). Results: We found that 228 KB were performed, 78 (34.2%) in period 1, 91 (39.9%) in period 2, and 59 (25.9%) in period 3. The median age at KB was 11 (7-14) years. The main indications for KB were nephrotic syndrome (NS) (42.9%), hematuria and/or non-nephrotic proteinuria (35.5%), and acute kidney injury (13.2%). Primary glomerulopathies were more frequent (67.1%), particularly minimal change disease (MCD) (25.4%), IgA nephropathy (12.7%), and mesangioproliferative glomerulonephritis (GN) (8.8%). Of the secondary glomerulopathies, lupus nephritis (LN) was the most prevalent (11.8%). In group 1, hematuria and/or non-nephrotic proteinuria were the main reasons for KB, as opposed to NS in groups 2 and 3 (p < 0.01). LN showed an increasing trend (period 1-3: 2.6%-5.3%) and focal segmental glomerular sclerosis (FSGS) showed a slight decreasing trend (period 1-3: 3.1%-1.8%), without statistical significance. Conclusions: The main indication for KB was NS, which increased over time, justifying the finding of MCD as main histological diagnosis. LN showed an increase in incidence over time, while FSGS cases did not increase.

RESUMO Introdução: A biópsia renal (BR) percutânea é fundamental para diagnóstico e manejo de diversas patologias renais. Dados nacionais sobre BR nativa em pacientes pediátricos são escassos. Nosso objetivo foi revisar características demográficas, clínicas e padrões histopatológicos em crianças submetidas a BR percutânea nativa ao longo de 24 anos. Métodos: Estudo observacional retrospectivo de pacientes submetidos a BR percutâneas nativas em unidade de nefrologia pediátrica entre 1998 e 2021, comparando três períodos: período 1 (1998-2005), período 2 (2006-2013), período 3 (2014-2021). Resultados: Constatamos que foram realizadas 228 BR, 78 (34,2%) no período 1, 91 (39,9%) no período 2, 59 (25,9%) no período 3. A idade mediana na BR foi 11 (7-14) anos. As principais indicações para BR foram síndrome nefrótica (SN) (42,9%), hematúria e/ou proteinúria não nefrótica (35,5%), lesão renal aguda (13,2%). Glomerulopatias primárias foram mais frequentes (67,1%), principalmente doença de lesão mínima (DLM) (25,4%), nefropatia por IgA (12,7%), glomerulonefrite mesangioproliferativa (GN) (8,8%). Das glomerulopatias secundárias, nefrite lúpica (NL) foi a mais prevalente (11,8%). No grupo 1, hematúria e/ou a proteinúria não nefrótica foram os principais motivos para BR, ao contrário da SN nos grupos 2 e 3 (p < 0,01). A NL apresentou tendência crescente (período 1-3: 2,6%-5,3%) e a glomeruloesclerose segmentar focal (GESF) apresentou leve tendência decrescente (período 1-3: 3,1%-1,8%), sem significância estatística. Conclusões: A principal indicação para BR foi SN, que aumentou ao longo do tempo, justificando o achado de DLM como principal diagnóstico histológico. A NL apresentou aumento na incidência ao longo do tempo, enquanto os casos de GESF não aumentaram.

Pulmonary tuberculosis masquerading as a mass cancer lesion: A rare case report and review of literature.

Key Clinical Message: Despite being generally treatable and preventative, pulmonary tuberculosis (PTB) is one of the most common infectious agents that cause death. Misdiagnosis of TB frequently leads to unwarranted diagnostic procedures and postpones the start of treatment. Abstract: Pulmonary tuberculosis (PTB) can present with various unusual radiological and clinical characteristics. Misdiagnosis of TB frequently leads to unwarranted diagnostic procedures and postpones the start of treatment. Here, we describe a 50-year-old man who presented with a cancerous-type lesion on radiological findings and atypical symptoms that led to an initial diagnosis of lung cancer. However, histopathology and biopsy of the lung lesion revealed chronic granulomatous inflammation with caseous necrosis, confirming PTB as the true cause, with no further indications of malignancy.

Tubular Carcinoma of the Breast: The Possibility to Omit Sentinel Lymph Node Biopsy.

Background/Aim: Tubular breast carcinoma, classified as a special type of invasive cancer, has a good prognosis. This study aimed to retrospectively investigate the clinical and pathological characteristics of 32 tubular carcinoma cases enrolled at our institution, with a focus on exploring the potential for treatment de-escalation. Patients and Methods: The study included all patients diagnosed with tubular breast carcinoma at our hospital between January 2005 and December 2021. In addition, 549 patients with ductal carcinoma in situ (DCIS) and 1,524 patients with stage I and II invasive cancers [not otherwise specified (NOS)] were selected for comparison. Results: All participants were female, with an average age of 54.4 years. The median follow-up duration was 64 months. The median tumor diameter was 7 mm, and all cases were Luminal A type. Moreover, no lymph vascular invasion was observed in any case, and no local recurrence, distant metastasis, or death occurred. The sentinel lymph node positive rate was 0% in the tubular carcinoma group, significantly lower than that in the NOS group (25.5%, p=0.0019) and not significantly different from that in the DCIS group (0.2%). The tubular carcinoma group tended to have better overall survival (OS) and disease-free survival (DFS) than the NOS group. Furthermore, the tubular carcinoma group was not inferior in OS and DFS compared to the DCIS group. Conclusion: Lymph node metastasis rate, OS, and DFS of the tubular carcinoma group are comparable to those of the DCIS group. Sentinel lymph node biopsy for tubular carcinoma can be omitted with an accurate preoperative diagnosis.

Colposcopically Directed Biopsy Before Ablative Treatment Versus Direct Ablative Treatment in Patients With Cervical Oncogenic HPV.

Background/Aim: In the past, the standard of care for women with abnormal cervical cytology has been the performance of colposcopically guided biopsy, followed by conization or large loop excision of the transition zone (LLETZ) where biopsy revealed pre-cancerous or cancerous areas. More straightforward protocols are emerging which advocate performing LLETZ in all women with highly suspicious cytology, suspicious colposcopic impression, or the presence of high-risk oncogenic human papilloma virus (HPV) strains in their cervical swabs. This, theoretically, would reduce the rate of false-negative diagnoses, but at the price of overtreating a significant number of healthy women. Patients and Methods: We retrospectively analyzed cervical cancer screening protocols in two large cohorts of women with high-risk HPV. The study compared outcomes between patients undergoing a colposcopically directed biopsy before LLETZ (n=683) and those proceeding directly to LLETZ without a biopsy (n=136). The primary focus was to assess whether intervening biopsies would reduce unnecessary ablative procedures without compromising the detection of high-grade lesions. Results: The biopsy group had a high false-negative rate, with several high-grade lesions (CIN3) and a case of invasive cancer initially underdiagnosed. Conversely, the direct-to-LLETZ approach, while ensuring no high-grade lesions were missed, led to overtreatment of lower grade lesions. Conclusion: These findings raise concern about the reliance on biopsy results for treatment decisions. Neither protocol was entirely satisfactory, although the more aggressive one avoided the potentially life-threatening consequence of false-negative results. Further research is mandatory to accurately diagnose all cases requiring aggressive treatment, without subjecting healthy women to ablative treatments they do not need.

Middle Rectal Artery Pseudoaneurysm: A Case of Massive Lower Gastrointestinal Bleeding Managed With Coil Embolization.

Pseudoaneurysms of the middle rectal artery are rare. When encountered, these have the potential for significant morbidity and mortality due to bleeding and potential rupture. Endovascular embolization is a feasible option in the management of these pseudoaneurysms. The present report describes a case of a 43-year-old male presenting with hemorrhagic shock secondary to lower gastrointestinal bleeding one day after undergoing excision of an external perineal condyloma, incision and drainage of a perirectal abscess, and biopsy of a perianal mass. Angiographic imaging revealed a right middle rectal artery pseudoaneurysm. Selective embolization of the right middle rectal artery and bilateral superior rectal arteries was successfully performed. At the two-week post-embolization follow-up, hemoglobin was stable, and the patient reported normal bowel movements with no episodes of bleeding per rectum.

Circulating tumor DNA to guide diagnosis and treatment of localized and locally advanced non-small cell lung cancer.

Liquid biopsy is a minimally invasive method for biomarkers detection in body fluids, particularly in blood, which offers an elevated and growing number of clinical applications in oncology. As a result of the improvement in the techniques for DNA analysis, above all next-generation sequencing (NGS) assays, circulating tumor DNA (ctDNA) has become the most informing tumor-derived material for most types of cancer, including non-small cell lung cancer (NSCLC). Although ctDNA concentration is higher in patients with advanced tumors, it can be detected even in patients with early-stage disease. Therefore, numerous clinical applications of ctDNA in the management of early-stage lung cancer are emerging, such as lung cancer screening, the identification of minimal residual disease (MRD), and the prediction of relapse before radiologic progression. Moreover, a high number of clinical trials are ongoing to better define the impact of ctDNA evaluation in this setting. Aim of this review is to offer a comprehensive overview of the most relevant implementations in using ctDNA for the management of early-stage lung cancer, addressing available data, technical aspects, limitations, and future perspectives.

[Endoscopic ultrasound-guided liver biopsy: current status and prospects].

Liver biopsy is an important means of clinical diagnosis and treatment of liver diseases, but it is not easily accepted by patients because of its invasiveness. The most commonly employed liver biopsy approaches are percutaneous or transjugular. Endoscopic ultrasound-guided liver biopsy (EUS-LB), a newly emerging transjugular technique, has been widely studied and applied in recent years, but its application in China is less common. The EUS-LB has the advantages of high safety and comfort, simultaneous sampling of both liver lobes, and adequate sampling volume; however, it also has the disadvantages of high requirements for hardware, operators, and cost. This article reviews the clinical application of EUS-LB in accordance with pertinent research findings from recent years and discusses its advantages, disadvantages, and implementation feasibility.

Alterations of Placental Sodium in Preeclampsia: Trophoblast Responses.

BACKGROUND: Evidence suggests that increasing salt intake in pregnancy lowers blood pressure, protecting against preeclampsia. We hypothesized that sodium (Na+) evokes beneficial placental signals that are disrupted in preeclampsia. METHODS: Blood and urine were collected from nonpregnant women of reproductive age (n=26) and pregnant women with (n=50) and without (n=55) preeclampsia, along with placental biopsies. Human trophoblast cell lines and primary human trophoblasts were cultured with varying Na+ concentrations. RESULTS: Women with preeclampsia had reduced placental and urinary Na+ concentrations, yet increased urinary angiotensinogen and reduced active renin, aldosterone concentrations, and osmotic response signal TonEBP (tonicity-responsive enhancer binding protein) expression. In trophoblast cell cultures, TonEBP was consistently increased upon augmented Na+ exposure. Mechanistically, inhibiting Na+/K+-ATPase or adding mannitol evoked the TonEBP response, whereas inhibition of cytoskeletal signaling abolished it. CONCLUSIONS: Enhanced Na+ availability induced osmotic gradient-dependent cytoskeletal signals in trophoblasts, resulting in proangiogenic responses. As placental salt availability is compromised in preeclampsia, adverse systemic responses are thus conceivable.

Changes in Numbers of Glomerular Macrophages Between Two Consecutive Biopsies and the Association With Renal Transplant Graft Survival.

BACKGROUND: Macrophages are involved in kidney transplants. The aim of the study was to investigate if changes exist in the levels of glomerular macrophage index (GMI) between two consecutive kidney transplant biopsies, and if so to determine their potential impact on graft survival. METHODS: Two consecutive biopsies were performed on the same renal graft in 623 patients. GMI was categorized into three GMI classes: ≤1.8 Low, 1.9-4.5 Medium, and ≥4.6 High. This division yielded nine possible switches between the first and second biopsies (Low-Low, Low-Medium, etc.). Cox-regressions were used and hazard ratios (HR) with 95% confidence interval (CI) are presented. RESULTS: The worst graft survival was observed in the High-High group, and the best graft survival was observed in the Low-Low and High-Low groups. Compared to the High-High group, a reduction of risk was observed in nearly all other decreasing groups (reductions between 65% and 80% of graft loss). After adjustment for covariates, the risk for graft-loss was lower in the Low-Low (HR = 0.24, CI 0.13-0.46), Low-Medium (HR = 0.25, CI 0.11-0.55), Medium-Low (HR = 0.29, CI 0.11-0.77), and the High-Low GMI (HR = 0.31, CI 0.10-0.98) groups compared to the High-High group as the reference. CONCLUSIONS: GMI may change dynamically, and the latest finding is of most prognostic importance. GMI should be considered in all evaluations of biopsy findings since high or increasing GMI levels are associated with shorter graft survival. Future studies need to consider therapeutic strategies to lower or maintain a low GMI. A high GMI besides a vague histological finding should be considered as a warning sign requiring more frequent clinical follow up.

Implantation and removal of central temporary paracorporeal biventricular support for COVID-19-associated myocarditis.

This case report illustrates how to implant a central paracorporeal temporary biventricular assist device in a 17-year-old patient with acute heart failure due to a fulminant form of coronavirus disease 2019 myocarditis. The procedure was carried out after prior veno-arterial extracorporeal membrane oxygenation support. Myocardial biopsies and biventricular assist device explants are also included in the report. The patient was weaned on postoperative day 6 and discharged without any significant complications. One year after the event, the patient remains asymptomatic with normal biventricular function and a normal lifestyle.

Clinical Characteristics and Mechanisms of Acute Myocarditis.

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05335928.

CDKN2A copy number alteration in bladder cancer: Integrative analysis in patient-derived xenografts and cancer patients.

Bladder cancer (BlCa) is an extensively heterogeneous disease that leads to great variability in tumor evolution scenarios and lifelong patient surveillance, emphasizing the need for modern, minimally invasive precision medicine. Here, we explored the clinical significance of copy number alterations (CNAs) in BlCa. CNA profiling was performed in 15 patient-derived xenografts (PDXs) and validated in The Cancer Genome Atlas BlCa (TCGA-BLCA; n = 408) and Lindgren et al. (n = 143) cohorts. CDKN2A copy number loss was identified as the most frequent CNA in bladder tumors, associated with reduced CDKN2A expression, tumors of a papillary phenotype, and prolonged PDX survival. The study's screening cohort consisted of 243 BlCa patients, and CDKN2A copy number was assessed in genomic DNA and cell-free DNA (cfDNA) from 217 tumors and 189 pre-treatment serum samples, respectively. CDKN2A copy number loss was correlated with superior disease-free and progression-free survival of non-muscle-invasive BlCa (NMIBC) patients. Moreover, a higher CDKN2A index (CDKN2A/LEP ratio) in pre-treatment cfDNA was associated with advanced tumor stage and grade and short-term NMIBC progression to invasive disease, while multivariate models fitted for CDKN2A index in pre-treatment cfDNA offered superior risk stratification of T1/high-grade and EORTC high-risk patients, enhancing prediction of treatment outcome. CDKN2A copy number status could serve as a minimally invasive tool to improve risk stratification and support personalized prognosis in BlCa.

Clinical relevance of circulating tumor DNA in ovarian cancer: current issues and future opportunities.

Ovarian cancer (OC) is the most lethal gynecologic malignancy worldwide. Due to the lack of effective screening and early detection strategies, many patients with OC are diagnosed with advanced disease, where treatment is rarely curative. Moreover, OC is characterized by high intratumor heterogeneity, which represents a major barrier to the development of effective treatments. Conventional tumor biopsy and blood-based biomarkers, such as cancer antigen 125 (CA125), have different limitations. Liquid biopsy has recently emerged as an attractive and promising area of investigation in oncology, due to its minimally invasive, safe, comprehensive, and real-time dynamic nature. Preliminary evidence suggests a potential role of liquid biopsy to refine OC management, by improving screening, early diagnosis, assessment of response to treatment, detection, and profiling of drug resistance. The current knowledge and the potential clinical value of liquid biopsy in OC is discussed in this review to provide an overview of the clinical settings in which its use might support and improve diagnosis and treatment.

Hypereosinophilia and Left Ventricular Thrombus: A Case Report and Literature Review.

Left ventricular thrombus (LVT) has historically been reported as a complication of acute left ventricular (LV) myocardial infarction. It is most commonly observed in cases of LV systolic dysfunction attributed to ischemic or nonischemic etiologies. Conversely, the occurrence of LVT in normal LV systolic function is an exceptionally rare presentation and is predominantly associated with conditions such as hypereosinophilic syndrome (HES), cardiac amyloidosis, left ventricular noncompaction, hypertrophic cardiomyopathy (HCM), hypercoagulability states, immune-mediated disorders, and malignancies. Notably, hypereosinophilia (HE) has been linked with thrombotic events. Intracardiac thrombus is a well-known complication of eosinophilic myocarditis (EM) or Loeffler endomyocarditis, both of which are considered clinical manifestations of HES. We present a case of a 63-year-old male with normal LV systolic function, HE, and noncontributory hypercoagulability workup, who presented with thromboembolic complications arising from LVT. Interestingly, the diagnostic evaluation for EM and Loeffler endocarditis was nonconfirmatory. Additionally, we performed a literature review to delineate all similar cases. This article also outlines the pathophysiology, diagnosis, and treatment approaches for hypereosinophilic cardiac involvement with a specific focus on LVT.

A Case Presentation of Well-Differentiated Hepatocellular Carcinoma With No Sign of Liver Disease.

The type of liver cancer that occurs most frequently is hepatocellular carcinoma (HCC). The majority of cases of HCC are secondary to alcoholic cirrhosis or viral hepatitis. The presence of malignant cells with modest nuclear atypia that resemble normal hepatocytes and the lack of bare nuclei in the smears, which shows the neoplastic hepatocytes' capacity, are characteristics of a well-differentiated HCC plasma membrane to tolerate smearing. We present the case of an 83-year-old male patient with a well-differentiated HCC, who had no etiological factors and no signs of alcohol cirrhotic liver, or any symptoms of liver disease which are the main causes of the HCC.

Masquerade of an emergency: cardiac tamponade as a deceptive presentation of primary cardiac diffuse large b-cell lymphoma-a case report.

Background: Primary cardiac diffuse large B-cell lymphoma (CDLBCL) is an exceptionally rare entity, estimated to represent less than 1% of all primary cardiac tumours. In this case report, we emphasize the diagnostic importance of multimodality imaging and the need for additional procedures, such as tissue biopsy, in a case with a primary cardiac lymphoma presenting with cardiac tamponade. Case summary: An 80-year-old male was admitted to the emergency department with a life-threatening tamponade demanding immediate sternotomy. Pre-operative echocardiography unveiled pericardial effusion and a thickened apex. While computed tomography ruled out an aortic dissection, surgery revealed an unexpected vascular-rich mass at the right ventricle and apex, too perilous for biopsy. Post-operative imaging misinterpreted this mass as a benign haematoma. Subsequently, the patient was admitted to the intensive care unit, but after a conservative treatment strategy, the patient died. An autopsy revealed a primary CDLBCL. Discussion: This case demonstrates the deceptive nature of primary CDLBCL, often complicated by cardiac tamponade. It underscores the pivotal role of pathologic assessment, even amidst the perils of sternotomy, to determine the origin of abnormal cardiac masses. A heightened awareness among physicians is imperative, for such elusive diagnoses may slip by, with potentially fatal outcomes.

Robotic-assisted laparoscopic radical prostatectomy for treatment of a newly identified lesion revealed no viable cells in the previously treated area with microwave focal therapy.

Introduction: Histological outcome of the targeted focal therapy is in principle confirmed by targeted needle biopsy from the treated area in clinical trial. Herein, we report a rare case in which the MFT was followed by RARP. Case presentation: A 68-year-old man with PSA 9.6 ng/mL and PI-RADS 4 lesion in the right transition zone on multi-parametric MRI underwent MR/ultrasound fusion-guided targeted biopsy, which revealed grade-group 1 cancer. Targeted focal therapy with microwave ablation was performed, resulting in disappearance of the PI-RADS 4 lesion at post-operative 4 months. However, PSA rose to 11.5 ng/mL, and a new PI-RADS 4 lesion, was identified in the left peripheral zone. RARP was performed to reveal new grade-group 3 cancer, and no viable cells in the previously treated area with MFT. Conclusion: RARP was safely performed even after MFT and proved the pathological complete response of microwave ablation.

The Skin and Lewy Body Disease.

This manuscript reviews the significant skin manifestations of Lewy body disease, including Parkinson's disease and dementia with Lewy bodies, and the diagnostic utility of skin biopsy. Besides classic motor and cognitive symptoms, non-motor manifestations, particularly dermatologic disorders, can play a crucial role in disease presentation and diagnosis. This review explores the intricate relationship between the skin and Lewy body disease. Seborrheic dermatitis, autoimmune blistering diseases (bullous pemphigoid and pemphigus), rosacea, and melanoma are scrutinized for their unique associations with Parkinson's disease, revealing potential links through shared pathophysiological mechanisms. Advances in diagnostic techniques allow the identification of promising biomarkers such as α-synuclein in samples obtained by skin punch biopsy. Understanding the dermatologic aspects of Lewy body disease not only contributes to its holistic characterization but also holds implications for innovative diagnostic approaches.

Initial United States experience with Medtronic Stealth Autoguide cranial robotic guidance platform.

OBJECTIVE: Stereotactic techniques play an important role in neurosurgery. The development of a miniaturized cranial robot with an efficient workflow and accurate surgical execution is an important step in a broader application of these techniques. Herein, the authors describe their experience with the Medtronic Stealth Autoguide miniaturized cranial robot. METHODS: A retrospective review of 75 cases from 2020 to 2022 was performed. The patients who had undergone surgery utilizing the Stealth Autoguide robot were analyzed for surgical indication and accuracy, operative time, and clinical outcome. The outcomes were defined as follows: for stereoelectroencephalography (SEEG), the electrode placement pattern that identified the seizure focus and did not require any revision or additional leads; for biopsy, the percentage of cases in which diagnostic tissue was obtained; and for laser interstitial thermal therapy (LITT), the percentage of cases in which laser fiber placement was adequate for ablation. Surgical complications were defined as any asymptomatic or symptomatic intracerebral hemorrhage, new neurological deficit, or need for electrode, laser fiber, or biopsy needle repositioning or revision. RESULTS: The Stealth Autoguide robot was utilized in 75 on-label cases, including 40 SEEG cases for seizure focus localization, 19 LITT cases, and 16 stereotactic biopsy cases. The mean real target error (RTE) at the entry was 1.48 ± 0.84 mm for biopsy, 1.36 ± 0.89 mm for Visualase laser fiber placement, and 1.24 ± 0.72 mm for SEEG. The mean RTE at the target was 1.56 ± 0.95 mm for biopsy needle placement, 1.42 ± 0.93 mm for Visualase laser fiber placement, and 1.31 ± 0.87 mm for SEEG electrode placement. The surgical time for unilateral SEEG cases took an average 52 minutes (average 6.5 mins/lead, average 8 electrodes). Bilateral SEEG cases took an average 105 minutes (average 7.5 mins/lead, average 14 electrodes). In the SEEG population, there were no revised or unsuccessful seizure localizations. For biopsy, diagnostic tissue was obtained in 100% of cases. For LITT, fiber placement was adequate for ablation in 100% of cases. There were no cases of symptomatic or asymptomatic intracerebral hemorrhage, and no cases required repositioning or replacement of the laser fiber, electrode, or biopsy needle. One patient experienced transient cranial nerve III palsy following laser ablation that resolved in 10 weeks. A failure of communication between the robotic platform and the Stealth Autoguide as a station required the cancellation of 1 procedure. CONCLUSIONS: The Medtronic Stealth Autoguide robot system is versatile across biopsy, SEEG, and laser ablation indications. Setup and surgical execution are efficient with a high degree of accuracy and consistency.

Safety and Technical Efficacy of Pediatric Brainstem Biopsies: An Updated Meta-Analysis of 1000+ Children.

BACKGROUND: Brainstem tumors represent ∼10% of pediatric brain tumors, ∼80% of these are diffuse midline glioma (DMG). Given invariably poor prognosis in DMG, there continues to be immense variation worldwide in performing biopsy of these lesions. Several contemporary studies in recent years have provided new data to elucidate the safety profile of biopsy and an updated meta-analysis is thus indicated. METHODS: We found 29 studies of pediatric brainstem biopsy in the last 20 years (2003-2023, 1002 children). We applied meta-analysis of proportions using a random-effects model to generate point estimates, confidence intervals, and measures of heterogeneity. RESULTS: 87% of procedures were stereotactic needle biopsies (of these, 62% with a frame, 14% without frame, and 24% robotic.) Biopsy resulted in a histological diagnosis ("technical yield") in 96.8% of cases (95% CI 95.4-98.2). Temporary complications were seen in 6% (95 CI 4-8), with the most common neurological complications being 1) cranial nerve dysfunction, 2) worsening or new ataxia, and 3) limb weakness. Permanent complications (excluding death) were seen in 1% (95% CI 0.5-2), most commonly including cranial nerve dysfunction and limb weakness. 5 deaths were reported in the entire pooled cohort of 1002 children (0.5%). CONCLUSIONS: When counseling families on the merits of brainstem biopsy in children, it is reasonable to state that permanent morbidity is rare (<2%). If biopsy is performed specifically to facilitate enrollment in clinical trials requiring a molecular diagnosis, the risks of biopsy outlined here should be weighed against potential benefits of trial enrollment.