Diagnostic magnetic resonance imaging characteristics of congenital mesoblastic nephroma: a retrospective multi-center International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG) radiology panel study

Justine N van der Beek; Jens-Peter Schenk; Carlo Morosi; Tom A Watson; Ana Coma; Norbert Graf; Tanzina Chowdhury; Gema L Ramírez-Villar; Filippo Spreafico; Nils Welter; Kristina Dzhuma; Harm van Tinteren; Ronald R de Krijger; Marry M van den Heuvel-Eibrink; Annemieke S Littooij

doi:10.1007/s00247-024-05918-4

Diagnostic magnetic resonance imaging characteristics of congenital mesoblastic nephroma: a retrospective multi-center International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG) radiology panel study

Pediatr Radiol. 2024 Apr 13. doi: 10.1007/s00247-024-05918-4. Online ahead of print.

Authors

Justine N van der Beek^{1

2}, Jens-Peter Schenk³, Carlo Morosi⁴, Tom A Watson⁵, Ana Coma⁶, Norbert Graf⁷, Tanzina Chowdhury⁸, Gema L Ramírez-Villar⁹, Filippo Spreafico¹⁰, Nils Welter⁷, Kristina Dzhuma^{11

12}, Harm van Tinteren¹³, Ronald R de Krijger^{13

14}, Marry M van den Heuvel-Eibrink^{13

15}, Annemieke S Littooij^{16

13}

Affiliations

¹ Department of Radiology and Nuclear Medicine, University Medical Center Utrecht/Wilhelmina Children's Hospital, Utrecht University, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands. j.n.vanderbeek-6@umcutrecht.nl.
² Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands. j.n.vanderbeek-6@umcutrecht.nl.
³ Clinic of Diagnostic and Interventional Radiology, Division of Pediatric Radiology, Heidelberg University Hospital, Heidelberg, Germany.
⁴ Department of Radiology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
⁵ Department of Paediatric Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
⁶ Department of Pediatric Radiology, Hospital Vall d'Hebron, Barcelona, Spain.
⁷ Department of Pediatric Oncology & Hematology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg, Germany.
⁸ Department of Haematology and Oncology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
⁹ Department of Paediatric Oncology, Hospital Universitario Virgen del Rocío, Seville, Spain.
¹⁰ Pediatric Oncology Unit, Department of Medical Oncology and Hematology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
¹¹ Developmental Biology and Cancer Department, University College London Great Ormond Street Institute of Child Health, London, UK.
¹² Department of Paediatric Urology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
¹³ Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
¹⁴ Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
¹⁵ Division of Child Health, Wilhelmina Children's Hospital, Utrecht University, Utrecht, The Netherlands.
¹⁶ Department of Radiology and Nuclear Medicine, University Medical Center Utrecht/Wilhelmina Children's Hospital, Utrecht University, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.

PMID: 38609702
DOI: 10.1007/s00247-024-05918-4

Abstract

Background: Congenital mesoblastic nephroma is the most common solid renal tumor in neonates. Therefore, patients <3 months of age are advised to undergo upfront nephrectomy, whereas invasive procedures at diagnosis in patients ≥3 months of age are discouraged by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Nevertheless, discriminating congenital mesoblastic nephroma, especially from the more common Wilms tumor, solely based on imaging remains difficult. Recently, magnetic resonance imaging (MRI) has become the preferred modality. Studies focusing on MRI characteristics of congenital mesoblastic nephroma are limited.

Objective: This study aims to identify diagnostic MRI characteristics of congenital mesoblastic nephroma in the largest series of patients to date.

Materials and methods: In this retrospective multicenter study, five SIOP-RTSG national review radiologists identified 52 diagnostic MRIs of histologically proven congenital mesoblastic nephromas. MRI was performed following SIOP-RTSG protocols, while radiologists assessed their national cases using a validated case report form.

Results: Patients (24/52 classic, 11/52 cellular, and 15/52 mixed type congenital mesoblastic nephroma, 2/52 unknown) had a median age of 1 month (range 1 day-3 months). Classic type congenital mesoblastic nephroma appeared homogeneous with a lack of hemorrhage, necrosis and/or cysts, showing a concentric ring sign in 14 (58.3%) patients. Cellular and mixed type congenital mesoblastic nephroma appeared more heterogeneous and were larger (311.6 and 174.2 cm³, respectively, versus 41.0 cm³ for the classic type (P<0.001)). All cases were predominantly T2-weighted isointense and T1-weighted hypointense, and mean overall apparent diffusion coefficient values ranged from 1.05-1.10×10^-3 mm²/s.

Conclusion: This retrospective international collaborative study showed classic type congenital mesoblastic nephroma predominantly presented as a homogeneous T2-weighted isointense mass with a typical concentric ring sign, whereas the cellular type appeared more heterogeneous. Future studies may use identified MRI characteristic of congenital mesoblastic nephroma for validation and for exploring the discriminative non-invasive value of MRI, especially from Wilms tumor.

Keywords: Congenital mesoblastic nephroma; Kidney neoplasms; Magnetic resonance imaging; Pediatrics; Radiology; Wilms tumor.

Grants and funding

341/Stichting Kinderen Kankervrij