Clinical prognostic factors in pediatric adrenocortical tumors: A meta-analysis.

Pediatric adrenocortical tumors (ACT) are rare and sometimes aggressive malignancies, but there is no consensus on the outcome predictors in children. A systematic search of MEDLINE, SCOPUS, Web of Science, and the Cochrane Library for studies from 1994 to 2020 about pediatric ACT was performed. In 42 studies, 1006 patients, aged 0-18 years, were included. The meta-analyses resulted in the following predictors of better outcome: age <4 years (P < .00001), nonsecreting tumors (P = .004), complete surgical resection (P < .00001), tumor volume (P < .0001), tumor weight (P < .00001), tumor maximum diameter (P = .0009), and Stage I disease (P < .00001). Moreover, patients affected by Cushing syndrome showed a worse outcome (P < .0001). International prospective studies should be implemented to standardize clinical prognostic factors evaluation, together with pathological scores, in the stratification of pediatric ACT.

Extra-appendicular neuroendocrine tumors: A report from the TREP project (2000-2020).

BACKGROUND: Extra-appendicular neuroendocrine tumors (NETs) are very rare tumors. While diagnostic and therapeutic guidelines are well established for adults, data on children and adolescents are lacking. PATIENTS AND METHODS: Patients with a diagnosis of extra-appendicular NET registered on the Tumori Rari in Età Pediatrica - Rare Tumors in Pediatric Age (TREP) from 2000 to 2020 were analyzed. Clinical characteristics including patients' presentation, tumor features, treatment, and outcome were reviewed. RESULTS: Twenty-seven patients with extra-appendicular NET registered on TREP with a median age of 173 months. The primary site was the pancreas (12) or bronchi (10) in the majority of cases. Other primary sites included the thymus, Meckel's diverticulum, and liver. Thirteen (48%) of tumors extended beyond the organ of origin: four invaded neighboring organs and/or regional nodes and nine involved distant metastases. The 3-year event-free survival (EFS) for those with localized disease was superior to those with metastatic disease (66.6% 95% CI 5-95% vs 33% 95% CI 5-68%, respectively; P = .005). A complete resection was feasible in 17 patients. The 3-year EFS in these patients was superior to those with no or incomplete resection (R0 vs R1/R2, respectively; P = .007). Overall, 16 children had no evidence of disease at follow-up, and one is alive with disease; five died, and five were lost to follow-up. CONCLUSIONS: Data from our experience demonstrated a wide heterogeneity of presentation and outcome of these tumors. Localized disease and complete surgical resection were the main prognostic factors of good outcome. Other therapies may have a role in prolonging survival in metastatic disease.

Pancreatoblastoma in children: EXPeRT/PARTNER diagnostic and therapeutic recommendations.

Pancreatoblastoma (PBL) is a rare malignant epithelial neoplasm that affects typically young children. Signs related to advanced upper-abdominal tumor accompanied by elevated serum α-fetoprotein levels in a young child suggest PBL, however histopathological confirmation is mandatory. The mainstay of the treatment is a complete surgical resection. Unresectable and/or metastatic PBL may become amenable to complete delayed surgery after neoadjuvant chemotherapy. This manuscript presents the international consensus recommendations for the diagnosis and treatment of children with PBL, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU-funded PARTNER (Paediatric Rare Tumors Network - European Registry) project.

Facing the challenges of very rare tumors of pediatric age: The European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) background, goals, and achievements.

It has become increasingly clear in recent years that we need to develop ad hoc strategies to combat very rare tumors (VRT) of pediatric age. In 2008, several schemes being run in different countries were pooled together to create the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) project: a cooperative study group that aimed to promote research in the relatively uncharted territory of rare tumors of pediatric age. EXPeRT members were able to activate different levels of cooperation to achieve their goals, and to obtain dedicated funding by participating in EU-financed projects. Their experiences emphasize the merits of networking, seeking new partnerships, joining forces, and pooling resources to extend the reach of research efforts, and ultimately improve the quality of patient care. Between 2018 and 2021, the EXPeRT has been active in establishing the Pediatric Rare Tumors Network - European Registry (PARTNER). This project had the main purposes of building a European common registry of pediatric VRT, but also the major task of developing diagnostic and treatment guidelines for VRT (or at least part of them). These clinical recommendations are the subject of a series of papers on Pediatric Blood and Cancer.

Adrenocortical tumours in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations.

Adrenocortical tumours (ACTs) are rare during childhood. A complete surgical resection provides the best chance of cure, but the role and efficacy of the adjuvant therapy are still controversial. Various histologic criteria of malignancy for ACTs adopted in children do not facilitate comparative studies and are not completely shared. Therefore, a sharp demarcation between benign and malignant lesions has not been recognised, making it difficult to identify who potentially needs perioperative therapy. This manuscript presents the internationally harmonised recommendations for the diagnosis and treatment of ACTs in children and adolescents, established by the European Cooperative Study Group for Paediatric Rare Tumours (EXPeRT) group within the EU-funded project PARTNER (Paediatric Rare Tumours Network - European Registry).

Thymoma and thymic carcinoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations.

Thymic tumors are epithelial tumors arising from the anterior mediastinum and constitute 0.2-1.5% of all adult malignancies but are exceptional in pediatric population. Thymic epithelial tumors (TETs) encompass a variety of histologic subtypes associated with different clinical outcomes. Due to its rarity in children, TETs' management requires a multidisciplinary approach. However, prognosis remains still poor, especially among patients with thymic carcinoma. This study presents the internationally recognized recommendations for the diagnosis and treatment of thymic tumors in children and adolescents, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) group within the EU-funded project Paediatric Rare Tumours Network - European Registry (PARTNER).

Treatment Strategies for Children With Relapsed Pancreatoblastoma: A Literature Review.

Pancreatoblastoma (PB) is a tumor typically seen in childhood. Despite its rarity, there are some internationally agreed recommendations for its first-line treatment, but very little is known about the management of relapse. We reviewed the literature on the treatment and outcome of children with progressing/recurrent PB, and the role of high-dose chemotherapy (HD-CT) or liver transplantation in difficult cases. A first analysis concerned 15 patients: liver metastases were the most frequent cause of first-line treatment failure. Eight patients underwent surgery, only 3 were irradiated. Various second-line chemotherapy regimens were adopted, with evidence of response in 8 children. The most often-used combinations included etoposide, cyclophosphamide/ifosfamide, and cisplatin/carboplatin. Overall, 7 patients are alive with a median follow-up of 24 months (range, 3 to 88 mo). In a separate analysis, considering patients in first-line or second-line treatment, we found 5 of 6 patients alive after HD-CT and 3 of 3 after liver transplantation. Our review shows that the outcome for patients with recurrent PB is not always dismal, especially when surgery is possible. Different chemotherapy combinations can be used, and HD-CT or liver transplantation may be considered in selected cases.

Could a careful clinical examination distinguish physiologic phimosis from balanitis xerotica obliterans in children?

The diagnosis of balanitis xerotica obliterans (BXO) in children may be challenging, since clinical examination only could lead to an underestimation of its incidence. The aim of this retrospective and single-centre study is to assess the diagnostic performance of clinical examination, together with clinical history, in identifying BXO. Ninety-seven children underwent circumcision for phimosis from 2015 to 2019. Histology was routinely performed. Cohen's kappa coefficient, sensitivity, specificity, predictive values, likelihood ratios and accuracy of macroscopic appearance of the foreskin, steroid administration and past medical history were estimated. Forty-eight patients (50%) were affected by BXO; 31 of them (69%) presented with suggestive clinical signs. A strictured or whitish urethral meatus was detected during surgery in nine cases (19%); this was associated to allergic or immune diseases (p = 0.046). Foreskin appearance alone mildly correlated with histology (k = 0.494; p < 0.001) and it showed a diagnostic accuracy of 75%. The specificity and positive predictive value of abnormal macroscopic findings at examination, together with a positive clinical history for other allergic or immune diseases, and/or for balanitis, were 100% and the positive likelihood ratio was greater than 10. Conversely, sensitivity decreased to 4.5% (95% CI 0-11%).Conclusion: Foreskin appearance together with clinical history could predict BXO with certainty. However, since the absence of a positive medical history could not exclude the diagnosis, foreskin histology is still highly recommended. What is Known: • Occurrence of balanitis xerotica obliterans may be underestimated in children and it could lead to long-term complications. • The diagnostic accuracy of clinical examination is controversial. What is New: • Clinical signs together with patients' medical history present high specificity and positive predictive values but low sensitivity. • When suggestive clinical aspects are present, patient should be referred to surgery avoiding prolonged conservative treatment; and preputial histology is highly recommended.

Pheochromocytomas and paragangliomas in children: Data from the Italian Cooperative Study (TREP).

BACKGROUND: Pheochromocytomas (PCs) are neuroendocrine tumors arising from the chromaffin cells of the adrenal gland, and paragangliomas (PGLs) are their extra-adrenal counterparts arising from ganglia along the sympathetic/parasympathetic chain. Surgery is the cornerstone of treatment. A sporatic or inherited germline mutation is commonly associated. MATERIALS AND METHODS: Among over 1000 patients registered into the Tumori Rari in Età Pediatrica-rare tumors in pediatric age project-from 2000 to 2019, 50 were affected by PC/PGL. All clinical and therapeutic data were evaluated. RESULTS: Twenty-eight patients had PC and 22 had PGL. Age at diagnosis ranged between 5 and 17 years. Thirty-five patients had symptoms related to catecholamine hypersecretion; in 7 of 50 patients, diagnosis was incidental or done during assessment of a familial syndrome. In all cases, conventional imaging was effective to assess the presence of a tumor. In addition, 18 of 38 functional imaging studies were positive (61%). Forty-eight patients were eligible for surgery: a complete resection was more frequently achieved in PC than in PGL (26/28 vs 11/22). All relapses were treated with surgery alone, surgery plus medical treatment, or chemotherapy alone; one PC with metastasis at diagnosis received radiotherapy only. Forty-four patients were in the first, second, or third complete remission (10/50 recurred; 8/10 carried a germline mutation). Five of 50 patients were alive with disease. One patient died of disease. CONCLUSIONS: Surgery can be curative in most tumors but it may not be always effective in removing PGLs. Severe postsurgical sequelae may affect these patients. Genetic tests should always be considered in individuals affected, and genetic counseling should be offered to their families.

Outcome after surgery for solid pseudopapillary pancreatic tumors in children: Report from the TREP project-Italian Rare Tumors Study Group.

BACKGROUND: Solid pseudopapillary pancreatic tumors (SPPT) are an extremely rare entity in pediatric patients. Even if the role of radical surgical resection as primary treatment is well established, data about follow-up after pancreatic resection in children are scant. METHODS: A retrospective review of data from the Italian Pediatric Rare Tumor Registry (TREP) was performed. Short-term (<30 days) and long-term complications of different surgical resections, as well as long-term follow-up were evaluated. RESULTS: From January 2000 to present, 43 patients (male:female = 8:35) were enrolled. The median age at diagnosis was 13.2 years (range, 7-18). Nine children had an incidental diagnosis, whereas 26 complained of abdominal pain and 4 of palpable mass. Tumors arose either from the head of pancreas (n = 14) or from body/tail (n = 29): only one patient presented with metastatic disease. Resection was complete in all patients (cephalic duodenopancreatectomy vs distal resection). At follow-up (median, 8.4 years; range, 0-17 years), one recurrence occurred in a patient with intraoperative rupture. All patients are alive. Three pancreatic fistulas occurred in the body/tail group, whereas four complications occurred in the head group (one ileal ischemia, two stenosis of the pancreatic duct, and one chylous fistula). CONCLUSION: Surgery is the best therapeutic option for these tumors; hence, complete resection is mandatory. Extensive resections, including cephalic duodenopancreatectomy, are safe when performed in specialized centers. Long-term follow-up should be aimed to detect tumor recurrence and to evaluate residual pancreatic function.

Gastrointestinal tract carcinoma in pediatric and adolescent age: The Italian TREP project experience.

BACKGROUND: Gastrointestinal (GI) carcinomas are very rare in the pediatric and adolescent age range. We report the clinical features, treatment, and outcome of a series of children and adolescents with GI carcinoma prospectively registered in the Italian Tumori Rari in Età Pediatrica (TREP) project. METHODS: The TREP project developed diagnostic and therapeutic guidelines based on recommendations currently in use for adults. Clinical data were centrally registered and reviewed. RESULTS: Fifteen patients were registered over the years 2000-2016. Most of the tumors were colorectal carcinomas (12 cases). All but one patient had advanced-stage disease (American Joint Committee on Cancer stages III-IV), and the majority of patients had aggressive histological subtypes, i.e. poorly differentiated (G3) (five patients), mucinous (four patients), and signet ring (two patients) adenocarcinomas. Surgery was performed in 13 of 15 patients, and was radical in nine of 13 patients. Only one patient received postoperative radiotherapy. All patients received chemotherapy, with the addition of bevacizumab in two cases. Nine patients were still alive at the time of the present report, but two of them had only just completed their treatment program and one patient is still on treatment. Six patients died due to disease progression. CONCLUSIONS: This prospective report on pediatric GI tract carcinomas confirms the rarity and biological aggressiveness of these diseases in pediatric and adolescent age. Further prospective studies are needed to explore the distinct biology of tumor in this age group in order to find new therapeutic targeted agents.

Comparative retrospective study on the modalities of biopsying peripheral neuroblastic tumors: a report from the Italian Pediatric Surgical Oncology Group (GICOP).

BACKGROUND: Peripheral neuroblastic tumors are the most common extracranial solid neoplasms in children. Early and adequate tissue sampling may speed up the diagnostic process and ensure a prompt start of optimal treatment whenever needed. Different biopsy techniques have been described. The purpose of this multi-center study is to evaluate the accuracy and safety of the various examined techniques and to determine whether a preferential procedure exists. METHODS: All children who underwent a biopsy, from January 2010 to December 2014, as a result of being diagnosed with a peripheral neuroblastic tumor, were retrospectively reviewed. Data collected included patients' demographics, clinical presentation, intraoperative technical details, postoperative parameters, complications, and histology reports. The Mann-Whitney U and Fisher's exact tests were used for statistical analysis. RESULTS: The cohort included 100 patients, 32 of whom underwent an incisional biopsy (performed through open or minimally invasive access) (Group A), and the remaining 68 underwent multiple needle-core biopsies (either imaging-guided or laparoscopy/thoracoscopy-assisted) (Group B). Comparing the two groups revealed that Group A patients had a higher rate of complications, a greater need for postoperative analgesia, and required red blood cell transfusion more often. Overall adequacy rate was 94%, without significant differences between the two groups (100% vs. 91.2% for Group A and Group B, respectively, P = 0.0933). CONCLUSIONS: Both incision and needle-core biopsying methods provided sub-optimal to optimal sampling adequacy rates in children affected by peripheral neuroblastic tumors. However, the former method was associated with a higher risk of both intraoperative and postoperative complications compared with the latter.

Gastric leiomyoma in a child with Gorlin-Goltz syndrome: First pediatric case.

Gorlin-Goltz syndrome (GGS), also known as nevoid basal cell carcinoma syndrome (MIM 109 400), is a rare genetic condition with a prevalence between 1/56 000 and 1/256 000. Clinical presentation is usually characterized by multiple basal cell carcinomas, odontogenic jaw keratocysts, palmar or plantar pitting and skeletal anomalies. It is furthermore associated with the development of various tumors beside basal cell carcinoma, among which medulloblastoma is the most frequent. Increased incidence of other mesenchymal neoplasms, however, is also well known: recently the first adult case of gastric leiomyoma in GGS was reported, and the inclusion of "fibromas and leiomyomas of other organs" in the minor criteria for the diagnosis was suggested. We report the first case of a pediatric patient with GGS who also developed a gastric leiomyoma: the present case illustrates the need for this change to the diagnostic criteria to encompass the highly variable presentations and phenotype in GGS.

Appendiceal neuroendocrine tumours in childhood: Italian TREP project.

BACKGROUND: Neuroendocrine tumours (NETs) of the appendix are slow-growing tumours and, although rare, they are the most common gastrointestinal epithelial tumours in childhood and adolescence. The treatment and the follow-up screenings have not been standardised. In addition to this, although tumour size is considered the main prognostic variable to define the aggressiveness of approach, a precise cutoff needs to be established. METHODS: A total of 113 patients younger than 18 years with a diagnosis of appendiceal NETs were registered as of January 1, 2000, until May 30, 2013, within the Rare Tumors in Pediatric Age (TREP) project, an Italian multi-institutional network dedicated to rare tumours in children and adolescents. The recommendations of the Rare Tumors in Pediatric Age study included imaging and laboratory investigations. The treatment after appendectomy was decided on the basis of histology, tumour size, and imaging; primary reexcision (PRE) was not recommended in completely excised tumours, regardless of tumour size and invasiveness. RESULTS: A total of 113 of 113 patients had a diagnosis of well-differentiated NETs; in 108 of 113 the tumour was smaller than 2 cm and in 5, larger than 2 cm. Excision margins were free in 111 of 113 patients. In 3 of 113 a PRE was performed, and in 1 residual tumour was detected. All 113 of 113 patients are alive in complete remission (median follow-up of 41 months). CONCLUSIONS: Reported data and our experience showed that no relapse or death occurred in children and adolescents affected by appendiceal NETs. Appendectomy alone should be considered curative for most patients, and a more aggressive surgical approach is warranted in the cases with incompletely excised tumours.

Diagnostic Utility of a Modified Reticulin Algorithm in Pediatric Adrenocortical Neoplasms.

Pediatric adrenocortical neoplasms (ACNs) are extremely rare tumors in contrast to their adult counterparts. Distinguishing benign from malignant is challenging based on pure morphologic grounds. Previously, 2 scoring systems were proposed in pediatric ACN, including the Wieneke criteria (WC) and its modified version (modified WC [mWC]). In adults, the reticulin algorithm (RA) has proven inexpensive, reliable, predictive, and reproducible; however, it has been validated only recently in children in a limited number of cases. This study aims to assess the RA utility compared with other scoring systems in a series of 92 pediatric ACNs. All cases were individually scored, and mitotic rate cutoffs were recorded. Reticulin alterations were classified as quantitative and qualitative. Outcome data were available in 59/92. The median age was 5 years (0.1 to 18 y) with an M:F of 0.6. Clinical presentation included virilization (39%), Cushing syndrome (21%), other symptoms (4%), and asymptomatic (36%). The reticulin framework was intact in 27% and altered in 73% of cases, showing qualitative (22%), quantitative (73%), and both (5%) alterations. In patients with favorable outcomes, 59% showed either intact reticulin or qualitative alteration compared with the unfavorable outcome group, where 90% showed quantitative alterations. All scoring systems WC ( P < 0.0001), mWC ( P = 0.0003), and the adult/pediatric RA ( P < 0.0001) had predictive value. The RA is comparable to WC and mWC, easier to apply, and is the most sensitive histopathological approach to identifying aggressive behavior in pediatric ACN. Its integration into the WC might be helpful in ACN of uncertain malignant potential and deserves further investigation.

Inguinal Hernia Containing the Uterus in the Pediatric Patient: A Systematic Review.

BACKGROUND: Inguinal hernia containing the uterus in pediatric patients with normal karyotype and phenotype is an extremely rare entity, and no consensus is available concerning diagnosis, surgical management, and follow-up. METHODS: A systematic review according to the Synthesis Without Meta-analysis protocol was conducted. Studies including pediatric female patients with inguinal hernia containing the uterus were searched. Keywords and mesh term searches were conducted (Medline, Scopus, and Web of Science). We additionally reviewed our center's clinical records and found 1 patient with an inguinal uterus hernia that was included in the statistical analysis. RESULTS: Thirty-six articles and 73 patients were considered for this analysis. The median gestational age at birth was 36 weeks. The inguinal mass was first noticed at the median age of 1.5 months (0-18 months), on the left side in 61% (on the right in 16, 39%). Sixty percent of patients had no associated symptoms or signs; 37.5% showed symptoms and signs of an incarcerated hernia. Median age at surgery was 2 months (1-72 months). In all patients, one or both adnexa herniated with the uterus. An open approach was more frequently used (56.4%). Contralateral duct exploration and ligation was performed in 7 patients (24.1%). No postoperative complications or recurrence have been described. CONCLUSIONS: The data obtained do not allow us to draw univocal conclusions on which is the best management in these patients. It is still unclear if an elective approach in an asymptomatic patient might bear long-term consequences on reproductive functions. No surgical technique proved to be superior to others, but both the open and laparoscopic approaches seem to be effective without postoperative complications or recurrence.

Complicated acute appendicitis in children: the importance of stewarding antibiotic prescriptions.

BACKGROUND: The aim was to assess the success of a three-drug regimen, consisting of cefazoline, metronidazole and gentamicine, for the antimicrobial treatment of complicated appendicitis and to investigate predictors of failure. METHODS: This retrospective study included patients who had undergone appendectomy for complicated appendicitis from 2013 to 2018. The shift to second-line antibiotics was considered a failure. The choice was based upon clinical deterioration. Patients were grouped into 2 groups: localized complicated appendicitis (LCA) and extensively complicated appendicitis (ECA) for the study purpose. Univariate and multivariate analysis were performed to identify predictors of failure. RESULTS: Ninety patients (65.2%) with LCA and 48 patients (35%) with ECA were included. Three-drug regimen failed in 50 patients (36%) with a higher rate in the ECA group (50%, p=0.017). In a multivariate analysis, this failure was found to be associated with ECA (adjusted OR 3.00 [1.2-7.4], p=0.041). Children with ECA experienced a longer hospital stay (median length 8 days, p < 0.001) and antimicrobial therapy (median length 8 days, p < 0.001). However, no difference in the rate of surgical site infections was found (p=0.514). CONCLUSIONS: The institutional antibiotic stewardship program highlighted a high failure rate for the old threedrug regimen. A new protocol should be recommended, especially for the patients affected by ECA.

Radiotherapy for pediatric adrenocortical carcinoma - Review of the literature.

Background and purpose: Pediatric adrenocortical carcinoma (pACC) is a rare disease with poor prognosis. Publications on radiotherapy (RT) are scarce. This review summarizes the current data on RT for pACC and possibly provides first evidence to justify its use in this setting. Materials and methods: We searched the PubMed and Embase database for manuscripts regarding RT for pACC. Results: We included 17 manuscripts reporting on 76 patients treated with RT, after screening 2961 references and 269 full articles. In addition, we added data of 4 unreported pACC patients treated by co-authors. All reports based on retrospective data. Median age at first diagnosis was 11.1 years (70% female); 78% of patients presented with hormonal activity. RT was mostly performed for curative intent (78%). 88% of RT were administered during primary therapy. The site of RT was predominantly the local tumor bed (76%). Doses of RT ranged from 15 to 62 Gy (median 50 Gy). Information on target volumes or fractionation were lacking. Median follow-up was 6,9 years and 64% of the patients died of disease, with 33% alive without disease. In 16 of 48 patients with available follow-up data after adjuvant RT (33%) no recurrence was reported and in 3 of 9 patients palliative RT seemed to induce some benefit for the patient. Conclusions: Our first systematic review on RT for pACC provides too few data for any general recommendation, but adjuvant RT in patients with high risk might be considered. International collaborative studies are urgently needed to establish better evidence on the role of RT in this rare malignancy.

Primary lung carcinoma in children and adolescents: An analysis of the European Cooperative Study Group on Paediatric Rare Tumours (EXPeRT).

BACKGROUND: Primary lung carcinoma is an exceptionally rare childhood tumour, as per definition of the European Cooperative Study Group on Paediatric Rare Tumours (EXPeRT), with an incidence of 0.1-0.2/1,000,000 per year. Little is known about the clinical characteristics of children with primary lung carcinoma, a gap which this joint analysis of the EXPeRT group aimed to fill. PATIENTS AND METHODS: We performed a retrospective case series of children (aged 0-18 years) with primary lung carcinoma, as collected through the EXPeRT databases between 2000 and 2021. We recorded relevant clinical characteristics including treatment and outcome. RESULTS: Thirty-eight patients were identified with a median age of 12.8 years at diagnosis (range: 0-17). Mucoepidermoid carcinoma (MEC) was the most frequent entity (n = 20), followed by adenocarcinoma (n = 12), squamous cell carcinoma (n = 4), adenosquamous carcinoma (n = 1) and small-cell lung cancer (n = 1). Patients with MEC presented rarely with lymph node metastases (2/20 cases). Overall, 19/20 patients achieved long-lasting remission by surgical resection only. Patients with other histologies often presented in advanced stages (14/18 TNM stage IV). With multimodal treatment, 3-year overall survival was 52% ± 13%. While all patients with squamous cell carcinoma died, the 12 patients with adenocarcinoma had a 3-year overall survival of 64% ± 15%. CONCLUSIONS: Primary lung carcinomas rarely occur in children. While the outcome of children with MEC is favourable with surgery alone, patients with other histotypes have a poor prognosis, despite aggressive treatment, highlighting the need to develop new strategies for these children, such as mutation-guided treatment.