Renal cell carcinoma in children and adolescents: A retrospective study of a French-Italian series of 93 cases.

Renal cell carcinomas represent 2 to 5% of kidney malignancies in children and adolescents. Appropriate diagnostic and classification are crucial for the correct management of the patients and in order to avoid inappropriate preoperative chemotherapy, which is usually recommended if a Wilms tumor is suspected.

a French-Italian series of 93 renal cell carcinomas collected from 1990 to 2019 in patients aged less than 18 years old was reclassified according to the 2016 WHO classification and the latest literature. TFE3 and TFEB FISH analyses and a panel of immunohistochemical stains were applied.

The median age at diagnosis was 11 years (range: 9 months - 17 years). MiT family (MiTF) translocation renal cell carcinomas accounted for 52% of the tumors, followed by papillary renal cell carcinomas (20%) and unclassified renal cell carcinomas (13%). Other subtypes, such as SDHB-deficient and Fumarate hydratase-deficient renal cell carcinomas, represented 1 to 3% of the cases. We also described a case of ALK-rearranged renal cell carcinoma with a metanephric adenoma-like morphology.

A precise histological diagnosis is mandatory as targeted therapy could be applied for some RCC subtypes, i.e., MiTF-translocation and ALK-translocation renal cell carcinomas. Moreover, some RCC subtypes may be associated with a predisposition syndrome that will impact patients' and family's management and genetic counseling. A precise RCC subtype is also mandatory for the clinical management of the patients and the inclusion in new prospective clinical trials.

Histopathology. 2022 Mar 03 [Epub ahead of print]

Thomas Denize, Simona Massa, Alexander Valent, Lucia Militti, Alessia Bertolotti, Marta Barisella, Nathalie Rioux-Leclercq, Gabriel G Malouf, Filippo Spreafico, Arnauld Verschuur, Justine van der Beek, Lieve Tytgat, Marry M van den Heuvel-Eibrink, Gordan Vujanic, Paola Collini, Aurore Coulomb

Department of Pathology, Sorbonne Université, Assistance Publique Hôpitaux de Paris - Hôpital Armand Trousseau, Paris, France., Department of Diagnostic Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy., Service de Génétique des tumeurs, Département de Pathologie, Institut Gustave Roussy, Villejuif, France., Department of Pathology, Rennes University Hospital, Rennes, France., Service d'Oncologie Médicale, Institut de Cancérologie de Strasbourg, Strasbourg, France., Pediatric Oncology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy., Department of Pediatric Oncology, Hôpital d'enfants de la Timone, Marseille, France., Princess Máxima Center for Pediatric Oncology, and Utrecht University, Utrecht, The Netherlands., Department of Pathology, Sidra Medicine / Weill Cornell Medicine, Doha, Qatar., Soft Tissue and Bone Pathology and Pediatric Pathology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.