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 recog-

Nasopharyngeal carcinoma (NPC) is a rare pediatric tumor. Collaborative studies performed over the last decades showed improved results compared to historical data, but standardized guidelines for diagnosis and management of pediatric NPC are still unavailable. This study presents a European consensus guideline for the diagnosis and treatment of pediatric NPC developed by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT). Main recommendations include induction chemotherapy with cisplatin and 5‐flurouracil, concomitant chemoradiotherapy in advanced disease, and to consider maintenance treatment with interferon beta (IFN‐β) for selected high‐risk patients. Dose adjustments of radiotherapy based on response to induction chemotherapy may decrease the rates of long‐term treatment‐related complications that affect most of the survivors.

The PARTNER project (Paediatric Rare Tumours Network ‐ European Registry) was launched in 2016. PARTNER aims to create a European Registry dedicated to children and adolescents with very rare tumors (VRT). It links existing national registries and provides a registry for those countries in which a VRT registry has not yet been created. This consortium is composed of the various national cooperative groups and their respective member institutions. The strategic value of this project is based on the Europe‐wide data collection concerning the treatment of VRTs. These data are provided to experts and constitute the basis for new clinical practice guidelines for use by ERN (European Reference Network) and non‐ERN institutions. The proposed tasks and milestones will increase collaboration in the field of pediatric oncology among member states and will also facilitate the inclusion of low health expenditure average rate (LHEAR) countries in this process. In addition, this project creates a platform for VRTs that may represent a model on how to elaborate a comprehensive approach (case registration, international case consultation and treatment recommendations, and website to provide information for parents/patients) for rare diseases.

Background Medulloblastomas may occur in a predisposition context, including familial adenomatosis polyposis. Medulloblastomas related to a germline pathogenic variant of adenomatous polyposis coli (APC) remain rare and poorly described. Their similarities with sporadic WNT medulloblastomas still require description. Methods We performed a multicentric retrospective review of 12 patients treated between 1988 and 2018 for medulloblastoma with an identified or highly suspected (personal or familial history) APC germline pathogenic variant. We report personal and familial history APC gene pathogenic variants whenever available: clinical and histologic characteristics of the medulloblastoma, treatments, and long-term outcome, including second tumor and late sequelae. Results Medulloblastomas associated with APC pathogenic variants are mainly classic (11/11 patients, 1 not available), nonmetastatic (10/12 patients) medulloblastomas, with nuclear immunoreactivity for ß-catenin (9/9 tested cases). Ten of 11 assessable patients are disease free with a median follow-up of 10.7 years (range, 1–28 y). Secondary tumors included desmoid tumors in 7 patients (9 tumors), 1 thyroid carcinoma, 2 pilomatricomas, 1 osteoma, 1 vertebral hemangioma, and 1 malignant triton in the radiation field, which caused the only cancer-related death in our series. Conclusions Medulloblastomas associated with an APC pathogenic variant have an overall favorable outcome, even for metastatic tumors. Yet, long-term survival is clouded by second tumor occurrence; treatment may play some role in some of these second malignancies. Our findings raise the question of applying a de-escalation therapeutic protocol to treat patients with APC germline pathogenic variants given the excellent outcome, and reduced intensity of craniospinal irradiation may be further evaluated.