Let it glow: Intraoperative visualization of pulmonary metastases using pafolacianine, a next-generation fluorescent agent, for young adults undergoing pulmonary metastasectomy.

A new generation of disease-specific molecular imaging agents is poised to revolutionize fluorescence-guided surgery. Pafolacianine has been approved for adult lung and ovarian cancers. We demonstrate a proof of concept for pediatric surgeons treating young adults with pulmonary metastatic sarcomas. Five successful fluorescence-guided pulmonary metastasectomy operations were performed in young adult patients with metastatic osteosarcoma or Ewing sarcoma following administration of pafolacianine. All osteosarcoma lesions identified using standard techniques were also markedly fluorescent in patients. Novel fluorescent molecular agents targeted to tumor-specific receptors have promise of increased sensitivity and specificity for detecting metastatic nodules and enhancing surgical clearance of disease.

Clinical Consensus Statement on the Use of Indocyanine Green Fluorescence-guided Surgery in Pediatric Patients.

BACKGROUND AND AIMS: Indocyanine Green Fluorescence (ICG-F)- guided surgery is becoming an increasingly helpful tool in pediatric surgical care. This consensus statement investigates the utility of ICG-F in various pediatric surgical applications, primarily focusing on its evidence base, safety, indications, use across different surgical specialties and dosing strategies. The aim is to establish an international consensus for ICG-F use in pediatric surgery. METHODS: An international panel of 15 pediatric surgeons from 9 countries was assembled. The structured process consisted of a rapid scoping review, iterative discussion sessions, mixed-methods studies with key stakeholders, and voting rounds on individual statements to create draft consensus statements. RESULTS: 100 articles were identified during the review and summarized by application. Based on this condensed evidence, consensus statements were generated after 3 iterative rounds of anonymous voting. Key areas of agreement were quality of evidence, the safety of ICG, pediatric surgical indications, utilization per surgical specialty, and dosing of ICG. CONCLUSION: This consensus statement aims to guide healthcare professionals in managing ICG-F use in pediatric surgical cases based on the best available evidence, key stakeholder consultation, and expert opinions. Despite ICG-F's promising potential, the need for higher-quality evidence, prospective trials, and safety studies is underscored. The consensus also provides a framework for pediatric surgeons to utilize ICG-F effectively. LEVEL OF EVIDENCE: III.

Contemporary surgical management of pediatric non-rhabdomyosarcoma soft tissue sarcoma.

Non-rhabdomyosarcoma soft tissue sarcoma (STS) comprises most STS in pediatric patients. It is a diverse set of over 30 histologic subtypes. Treatment is based on risk group determined by tumor size, grade, and the presence of metastases. Surgical resection is a cornerstone of therapy, as tumors are often resistant to chemotherapy or radiation. While patients with isolated tumors less than 5 cm may undergo upfront resection, strong consideration should be given to neoadjuvant chemoradiotherapy to ensure negative margins at surgical resection and optimal outcomes. Sentinel lymph node biopsy is strongly recommended for clear cell and epithelioid sarcomas. The most common metastatic site is the lung, and metastases should be resected at the end of therapy, when feasible. Unfortunately, many high-risk patients progress on therapy, and alternative strategies including earlier metastatic control require investigation.

Imaging adjuvants in pediatric surgical oncology.

Surgery is a crucial component of pediatric cancer treatment, but conventional methods may lack precision. Image-guided surgery, including fluorescent and radioguided techniques, offers promise for enhancing tumor localization and facilitating precise resection. Intraoperative molecular imaging utilizes agents like indocyanine green to direct surgeons to occult deposits of tumor and to delineate tumor margins. Next-generation agents target tumors directly to improve specificity. Radioguided surgery, employing tracers like metaiodobenzylguanidine (MIBG), complements fluorescent techniques by allowing for detection of tumors at a greater depth. Dual-labeled agents combining both modalities are under development. Three-dimensional modeling and virtual/augmented reality aid in preoperative planning and intraoperative guidance. The above techniques show great promise to benefit patients with pediatric tumors, and their continued development will almost certainly improve surgical outcomes.

Children and young adults with newly diagnosed rhabdomyosarcoma metastatic to bone treated on Children's Oncology Group studies.

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Despite bone metastases being present in 5% of patients at diagnosis, there are limited studies examining these outcomes. We sought to define the prognostic factors, clinical courses, and outcomes of children treated on Children's Oncology Group (COG) clinical trials with RMS metastatic to bone at diagnosis. METHODS: We performed a retrospective analysis of patients diagnosed with bone metastatic RMS enrolled on COG RMS clinical trials (D9802, D9803, ARST0431, or ARST08P1) between 1997 and 2013. RESULTS: RMS metastatic to bone was identified in 154 patients at a median age of 14.9 years at diagnosis. Fifty-eight percent of patients were male, 90% had metastases at additional sites, 74% had alveolar histology, and extremity was the most common primary site (31%). Eighty-six percent of patients (n = 133) received radiation therapy. The 3- and 5-year event-free survival (EFS) was 15.4% and 14.5%, respectively. The 3- and 5-year overall survival (OS) was 30.4% and 18.0%, respectively. We identified alveolar histology, FOXO1 fusion presence, unfavorable primary location, higher Oberlin score, and lack of radiation as poor prognostic characteristics for both EFS and OS in univariate analysis. Lack of radiation was not significant when excluding patients with events prior to 20 weeks. CONCLUSIONS: This study is the largest analysis of patients with bone metastatic RMS, and defines the poor overall outcomes and negative prognostic factors for these patients. They may be eligible for therapy deintensification for improved quality of life or pursuit of novel treatments/approaches, which are desperately needed.

Minimally invasive and robotic-assisted approaches applied to pediatric surgical oncology.

The management of pediatric tumors is complex, with surgery, chemotherapy, and radiotherapy being cornerstones in their treatment. Tumor removal is increasingly performed by a minimally invasive approach, which allows for quicker postoperative recovery and less postoperative pain. The goal of this report is to give an overview of minimally invasive surgical approaches for common pediatric tumors, with a focus on technical considerations and postoperative outcomes.

Central Venous Catheter Consideration in Pediatric Oncology: A Systematic Review and Meta-analysis From the American Pediatric Surgical Association Cancer Committee.

BACKGROUND: Tunneled central venous catheters (CVCs) are the cornerstone of modern oncologic practice. Establishing best practices for catheter management in children with cancer is essential to optimize care, but few guidelines exist to guide placement and management. OBJECTIVES: To address four questions: 1) Does catheter composition influence the incidence of complications; 2) Is there a platelet count below which catheter placement poses an increased risk of complications; 3) Is there an absolute neutrophil count (ANC) below which catheter placement poses an increased risk of complications; and 4) Are there best practices for the management of a central line associated bloodstream infection (CLABSI)? METHODS: Data Sources: English language articles in Ovid Medline, PubMed, Embase, Web of Science, and Cochrane Databases. STUDY SELECTION: Independently performed by 2 reviewers, disagreements resolved by a third reviewer. DATA EXTRACTION: Performed by 4 reviewers on forms designed by consensus, quality assessed by GRADE methodology. RESULTS: Data were extracted from 110 manuscripts. There was no significant difference in fracture rate, venous thrombosis, catheter occlusion or infection by catheter composition. Thrombocytopenia with minimum thresholds of 30,000-50,000 platelets/mcl was not associated with major hematoma. Limited evidence suggests a platelet count <30,000/mcL was associated with small increased risk of hematoma. While few studies found a significant increase in CLABSI in CVCs placed in neutropenic patients with ANC<500Kcells/dl, meta-analysis suggests a small increase in this population. Catheter removal remains recommended in complicated or persistent infections. Limited evidence supports antibiotic, ethanol, or hydrochloric lock therapy in definitive catheter salvage. No high-quality data were available to answer any of the proposed questions. CONCLUSIONS: Although over 15,000 tunneled catheters are placed annually in North America into children with cancer, there is a paucity of evidence to guide practice, suggesting multiple opportunities to improve care. LEVEL OF EVIDENCE: III. This study was registered as PROSPERO 2019 CRD42019124077.

Survival outcomes in pediatric patients with metastatic Ewing sarcoma who achieve a rapid complete response of pulmonary metastases.

PURPOSE: Our objectives were to compare overall survival (OS) and pulmonary relapse between patients with metastatic Ewing sarcoma (EWS) at diagnosis who achieve rapid complete response (RCR) and those with residual pulmonary nodules after induction chemotherapy (non-RCR). PATIENTS AND METHODS: This retrospective cohort study included children under 20 years with metastatic EWS treated from 2007 to 2020 at 19 institutions in the Pediatric Surgical Oncology Research Collaborative. Chi-square tests were conducted for differences among groups. Kaplan-Meier curves were generated for OS and pulmonary relapse. RESULTS: Among 148 patients with metastatic EWS at diagnosis, 61 (41.2%) achieved RCR. Five-year OS was 71.2% for patients who achieved RCR, and 50.2% for those without RCR (p = .04), and in multivariable regression among patients with isolated pulmonary metastases, RCR (hazards ratio [HR] 0.42; 95% confidence interval [CI]: 0.17-0.99) and whole lung irradiation (WLI) (HR 0.35; 95% CI: 0.16-0.77) were associated with improved survival. Pulmonary relapse occurred in 57 (37%) patients, including 18 (29%) in the RCR and 36 (41%) in the non-RCR groups (p = .14). Five-year pulmonary relapse rates did not significantly differ based on RCR (33.0%) versus non-RCR (47.0%, p = .13), or WLI (38.8%) versus no WLI (46.0%, p = .32). DISCUSSION: Patients with EWS who had isolated pulmonary metastases at diagnosis had improved OS if they achieved RCR and received WLI, despite having no significant differences in rates of pulmonary relapse.

Management of undifferentiated embryonal sarcoma of the liver: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: Undifferentiated embryonal sarcoma of the liver (UESL) is a rare tumor for which there are few evidence-based guidelines. The aim of this study was to define current management strategies and outcomes for these patients using a multi-institutional dataset curated by the Pediatric Surgical Oncology Research Collaborative. METHODS: Data were collected retrospectively for patients with UESL treated across 17 children's hospitals in North America from 1989 to 2019. Factors analyzed included patient and tumor characteristics, PRETEXT group, operative details, and neoadjuvant/adjuvant regimens. Event-free and overall survival (EFS, OS) were the primary and secondary outcomes, respectively. RESULTS: Seventy-eight patients were identified with a median age of 9.9 years [interquartile range [IQR): 7-12]. Twenty-seven patients underwent resection at diagnosis, and 47 patients underwent delayed resection, including eight liver transplants. Neoadjuvant chemotherapy led to a median change in maximum tumor diameter of 1.6 cm [IQR: 0.0-4.4] and greater than 90% tumor necrosis in 79% of the patients undergoing delayed resection. R0 resections were accomplished in 63 patients (81%). Univariate analysis found that metastatic disease impacted OS, and completeness of resection impacted both EFS and OS, while multivariate analysis revealed that R0 resection was associated with decreased expected hazards of experiencing an event [hazard ratio (HR): 0.14, 95% confidence interval (CI): 0.04-0.6]. At a median follow-up of 4 years [IQR: 2-8], the EFS was 70.0% [95% CI: 60%-82%] and OS was 83% [95% CI: 75%-93%]. CONCLUSION: Complete resection is associated with improved survival for patients with UESL. Neoadjuvant chemotherapy causes minimal radiographic response, but significant tumor necrosis.

Robotic-assisted Pediatric Thoracic and Abdominal Tumor Resection: An Initial Multi-center Review.

INTRODUCTION: Robotic-assisted minimally invasive surgery (RA-MIS) for tumor resection is an emerging technology in the pediatric population with significant promise but unproven safety and feasibility. METHODS: A multi-center retrospective review of patients ≤18 years undergoing RA-MIS tumor resection from December 2015-March 2023 was performed. Patient demographics, perioperative variables, and complication rates were analyzed. RESULTS: Thirty-nine procedures were performed on 38 patients (17 thoracic, 22 abdominal); 37% female and 68% non-Hispanic White. Median age at surgery was 8.3 years (IQR 5.7, 15.7); the youngest was 1.7 years-old. Thoracic operations included resections of neuroblastic tumors (n = 16) and a single paraganglioma. The most common abdominal operations included resections of neuroblastic tumors (n = 5), pheochromocytomas (n = 3), and angiomyolipomas (n = 3). Six patients underwent retroperitoneal lymph node dissection (RPLND) for paratesticular tumors. Median operating time for the cohort was 2:52 h (IQR 2:04, 4:31). Two thoracic cases required open conversion due to poor visualization and lack of working domain. All patients underwent complete tumor resection; one had tumor spillage from a positive margin (Wilms tumor). Median LOS was 1.5 days (IQR 1.1, 3.0). Postoperatively, one patient developed a chyle leak requiring interventional radiology drainage, but none required a return to the operating room. CONCLUSIONS: Robotic-assisted surgery is safe and feasible for tumor resection in carefully selected pediatric patients, achieving complete resection with minimal morbidity and short LOS. Resection should be performed by those with robotic expertise for optimal outcomes. LEVEL OF EVIDENCE: IV. TYPE OF STUDY: Original Clinical Research.

Adolescents and young adults with rhabdomyosarcoma: A report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group.

INTRODUCTION: The impact of established prognostic factors on survival outcomes for childhood rhabdomyosarcoma (RMS) have not been well described in the adolescent and young adult (AYA) RMS patient population. METHODS: This is a retrospective analysis of patients with newly diagnosed RMS enrolled between 1997 and 2016 on seven previously reported Children's Oncology Group (COG) clinical trials. Demographics, clinical features, treatment details, and outcome data were collected. Five-year event-free survival (EFS) and overall survival (OS) were estimated for patients diagnosed at age 15-39 years and those diagnosed under age 15 years using the Kaplan-Meier method. Log-rank test was used to compare prognostic factors for EFS and OS. Factors significant in the univariable analysis were included in a Cox proportional hazards regression model. Nonsignificant covariates were removed from the multiple regression model. RESULTS: Total 2151 patients including 402 AYAs were analyzed. AYAs were more likely to present with primary tumors ≥5 cm in size, metastatic disease, alveolar histology, and have FOXO1 fusions compared to children. Five-year EFS for the AYA cohort was 44.2% versus 67% for children (p < .001), and 5-year OS was 52% for the AYA cohort versus 78% for children (p < .001). Multivariable analysis revealed tumor site, size and invasiveness, clinical group, and histology were prognostic in AYAs. CONCLUSION: AYAs with RMS have a poorer prognosis compared to younger children due to multiple factors. Further research focused on AYAs to better understand RMS biology and improve treatments is critical to improve survival.

Children's Oncology Group's 2023 blueprint for research: Surgery.

Surgery plays a crucial role in the treatment of children with solid malignancies. A well-conducted operation is often essential for cure. Collaboration with the primary care team is important for determining if and when surgery should be performed, and if performed, an operation must be done in accordance with well-established standards. The long-term consequences of surgery also need to be considered. Indications and objectives for a procedure vary. Providing education and developing and analyzing new research protocols that include aims relevant to surgery are key objectives of the Surgery Discipline of the Children's Oncology Group. The critical evaluation of emerging technologies to ensure safe, effective procedures is another key objective. Through research, education, and advancing technologies, the role of the pediatric surgeon in the multidisciplinary care of children with solid malignancies will continue to evolve.

Management and Outcomes of Wilms Tumor With Suprarenal Intravascular Extension: A Pediatric Surgical Oncology Research Collaborative Study.

OBJECTIVE: The purpose of this study was to describe management and outcomes from a contemporary cohort of children with Wilms tumor complicated by inferior vena caval thrombus. BACKGROUND: The largest series of these patients was published almost 2 decades ago. Since then, neoadjuvant chemotherapy has been commonly used to manage these patients, and outcomes have not been reported. METHODS: Retrospective review of 19 North American centers between 2009 and 2019. Patient and disease characteristics, management, and outcomes were investigated and analyzed. RESULTS: Of 124 patients, 81% had favorable histology (FH), and 52% were stage IV. IVC thrombus level was infrahepatic in 53 (43%), intrahepatic in 32 (26%), suprahepatic in 14 (11%), and cardiac in 24 (19%). Neoadjuvant chemotherapy using a 3-drug regimen was administered in 82% and postresection radiation in 90%. Thrombus level regression was 45% overall, with suprahepatic level showing the best response (62%). Cardiopulmonary bypass (CPB) was potentially avoided in 67%. The perioperative complication rate was significantly lower after neoadjuvant chemotherapy [(25%) vs upfront surgery (55%); P =0.005]. CPB was not associated with higher complications [CPB (50%) vs no CPB (27%); P =0.08]. Two-year event-free survival was 93% and overall survival was 96%, higher in FH cases (FH 98% vs unfavorable histology/anaplastic 82%; P =0.73). Neither incomplete resection nor viable thrombus cells affected event-free survival or overall survival. CONCLUSIONS: Multimodal therapy resulted in excellent outcomes, even with advanced-stage disease and cardiac extension. Neoadjuvant chemotherapy decreased the need for CPB to facilitate resection. Complete thrombectomy may not always be necessary.

Intercostal nerve cryoablation reduces opioid utilization after thoracotomy in children with cancer.

BACKGROUND: Intercostal nerve cryoablation (INC) has shown promise as an adjunct method for analgesia in adults undergoing thoracotomy, but has yet to be widely used in children for this indication. We hypothesize that INC decreases opioid utilization in children undergoing thoracotomy for cancer operations. METHODS: A retrospective review was performed of children who underwent thoracotomy for cancer diagnosis at a freestanding children's hospital from 2018 to 2023. Patient characteristics, intraoperative data, and data on clinical course were collected. Patients were divided into those who underwent INC and those who underwent routine care for comparison. RESULTS: Twenty-six patients underwent 38 procedures at a median age of 16 years (range 5-21 years). INC was performed in 23 cases over a median of five intercostal levels (range 2-7). Total oral morphine equivalents during inpatient admission were significantly lower in INC patients (137.6 vs. 514.5 mg, p = .002). Routine care patients were more likely to be discharged with an opioid prescription (30.4% vs. 80.0%, p = .008). Length of stay was similar between patients with INC and routine care (4 vs. 5 days, p = .15). There were no differences in rates of reoperation or 30-day re-admission (emergency department or inpatient). CONCLUSTIONS: INC is a feasible and safe adjunct for children undergoing thoracotomy for cancer. INC is associated with reduced postoperative opioid utilization with respect to both inpatient use and outpatient prescriptions.

Critical elements of pediatric rhabdomyosarcoma surgery.

Rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, requires multimodal therapy which is determined by risk group stratification. Local control may be achieved by surgical resection, radiation, or both. Resection may occur upfront or following induction chemotherapy as a delayed primary excision. An R1 resection may allow a reduction in radiation exposure; however, debulking is not indicated nor is excision of residual masses at the end of therapy. Regional lymph node assessment is an important component of surgical care, as positive nodal basins require radiation. Depending on the tumor site and biology, sentinel lymph node biopsy vs biopsy of clinically or radiographically concerning nodes is indicated. Therapeutic lymph node dissection is never indicated. Familiarity with site-specific oncologic principles for RMS and participation in a multidisciplinary team including Pediatric Oncology and Radiation Oncology are necessary components of surgical care to ensure optimal outcomes.

Prognosis of children and young adults with newly diagnosed rhabdomyosarcoma metastatic to bone marrow treated on Children's Oncology Group studies.

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Metastatic disease occurs in 16% of all RMS cases and has a poor prognosis. There are limited studies examining the outcomes specific to patients with RMS metastatic to bone marrow despite an incidence of 6% at diagnosis. Our study aims to document the outcomes, prognostic factors, and clinical courses of children presenting with RMS metastatic to bone marrow treated on Children's Oncology Group (COG) cooperative trials. METHODS: We performed a retrospective analysis of the patients diagnosed with RMS metastatic to bone marrow between 1997 and 2013 enrolled on one of four COG RMS clinical trials of D9802, D9803, ARST0431, and ARST08P1. RESULTS: We identified 179 cases with RMS metastatic to bone marrow. Patients had a median age of 14.8 years, 58% were male, predominantly alveolar histology (76%), extremity was the most common primary site (32%), and 87% had metastatic disease to additional sites; 83% (n = 149) received radiation as a treatment modality. The 3- and 5-year event-free survival was 9.4% and 8.2%, respectively. The 3- and 5-year overall survival was 26.1% and 12.6%, respectively. Age ≥10 years, alveolar histology, FOXO1 fusion presence, unfavorable primary location, higher Oberlin score, and lack of radiation were identified as poor prognostic/predictive characteristics. CONCLUSIONS: This study represents the largest analysis of RMS metastatic to bone marrow, defining the poor prognostic outcome for these patients. These patients may be eligible for therapy deintensification or early pursuit of novel treatments/approaches that are desperately needed.

Association of Prophylactic Antibiotics With Early Infectious Complications in Children With Cancer Undergoing Central Venous Access Device Placement.

OBJECTIVE: To evaluate the impact of prophylactic antibiotics on early infectious complications after central venous access device (VAD) placement in children with cancer. SUMMARY OF BACKGROUND DATA: Despite the frequency of VAD procedures in children, the effectiveness of prophylactic antibiotics for reducing infectious complications is unknown. METHODS: This was a retrospective cohort study of children with cancer undergoing central VAD placement identified in the Pediatric Health Information System database between 2017-2021. The primary outcome was the rate of early infectious complications (composite surgical site infections, central line-associated bloodstream infections, and bacteremia). Multivariable logistic regression was used to evaluate factors associated with early infection, and heterogeneity of treatment effect of prophylactic antibiotics was compared across subgroups. RESULTS: 9,216 patients were included (6,058 ports and 3,158 tunneled lines). Prophylactic antibiotics were associated with lower early infectious complications overall (1.3% vs. 2.4%; OR 0.55 [95% C.I. 0.39-0.79], P<0.001), an effect demonstrated for tunneled lines (OR 0.59, 95% C.I.: 0.41-0.84) but not ports (OR 3.01, 95% C.I.: 0.66-13.78). On multivariate analysis, prophylactic antibiotics (OR 0.67, 95% C.I.: 0.45-0.97) and solid tumors (OR 0.38, 95% C.I.: 0.22-0.64) were associated with reduced odds of early infections, while tunneled lines (OR 20.78, 95% C.I.: 9.83-43.93) and acute myelogenous leukemia (OR 2.37, 95% C.I.: 1.58-3.57) had increased odds. CONCLUSIONS: Prophylactic antibiotics are associated with reduced early infectious complications after central VAD placement overall. Despite recommendations from multiple national organizations against prophylactic antibiotics, these findings suggest a benefit in children with malignancy undergoing tunneled line placement.

Unwrapping Nephrogenic Rests and Nephroblastomatosis for Pediatric Surgeons: A Systematic Review Utilizing the PICO Model by the APSA Cancer Committee.

BACKGROUND: Nephrogenic rests (NR) may represent precursor lesions for Wilms tumor (WT), but their clinical course is not fully understood and no guidelines for treatment exist. This study sought to evaluate the outcomes of pediatric patients with NRs related to traditional chemotherapy and surgery. METHODS: A PRISMA-P-compliant literature search was conducted in MEDLINE, Embase, CINAHL, Web of Science, COCHRANE, and SCOPUS from inception to June 2021. Clinical questions regarding the treatment of NRs, including chemotherapy and surgery, were developed in the population, intervention, comparison, and outcome format. RESULTS: Twenty-five studies including 1445 patients met inclusion criteria for evaluating chemotherapy compared to observation for NRs. Eighteen studies including 1392 patients met inclusion criteria for evaluating the role of surgery for NRs. Patients with isolated NRs who underwent observation progressed to WT 33% of the time; chemotherapy reduced the rate of WT to 3.9%. Observation of multiple NRs and diffuse hyperplastic perilobar nephroblastomatosis (DHPLN) led to progression to WT 50% and 100% of the time, respectively. Chemotherapy reduced the rate of WT to 34% for multiple NRs and 46% for DHPLN. Surgery for isolated NRs reduced the risk of WT development from 23.7% in patients with incomplete excision to 3.3% with complete excision; however, 96% of patients with incompletely excised NRs had bilateral disease. CONCLUSIONS: Observation with close surveillance for isolated NRs is safe. Treatment with chemotherapy is recommended for patients with multiple NRs and DHPLN. Surgical management of NRs should focus on renal function preservation. LEVEL OF EVIDENCE: Treatment study, Level III.

Multi-institutional assessment of the prevalence of neuroendocrine tumors in children undergoing laparoscopic appendectomy for acute appendicitis in the United States.

As non-operative management of acute appendicitis in children has become more common, missed incidental appendiceal pathology can be an unintended consequence. We assessed the prevalence of neuroendocrine tumors in appendectomy specimens from eight US children's hospitals from 2012 to 2021. The prevalence of neuroendocrine tumors (NET) was found to be 1:271, with a median age of 14 years and 62% female. Most tumors were small (median 6 mm; interquartile range [IQR]: 3-10), and no recurrence was noted during the follow-up period (median 22.5 months; IQR: 3-53). The possibility of delayed diagnosis of these tumors should be part of the discussion for non-operative management of pediatric acute appendicitis.