{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T09:06:25Z","timestamp":1776762385345,"version":"3.51.2"},"reference-count":26,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T00:00:00Z","timestamp":1776729600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Children"],"abstract":"<jats:p>Background: Non-Wilms renal tumours (NWRTs) are rare paediatric malignancies and account for a small but clinically significant proportion of childhood renal cancers. Due to their low incidence and biological heterogeneity, outcome data are limited, and management is largely extrapolated from international collaborative protocols. No national data describing the incidence and outcomes of NWRTs in children in the Republic of Ireland (ROI) have previously been published. Objective: To determine the incidence, treatment strategies, and survival outcomes of NWRTs in children in the ROI. Methods: A retrospective cohort study was conducted of all children under 16 years of age with histologically confirmed renal tumours diagnosed and treated at Children\u2019s Health Ireland (CHI) at Crumlin between January 2005 and December 2025. As CHI Crumlin is the single national paediatric oncology centre in the ROI, this cohort represents national case ascertainment for the study period. A total of 143 paediatric renal tumours were identified; Wilms tumours (n = 118) were excluded, leaving 25 children (17.48%) with NWRTs for analysis. No cases of bilateral renal tumours were identified. Histological subtypes included renal cell carcinoma (RCC), clear cell sarcoma of the kidney (CCSK), congenital mesoblastic nephroma (CMN), malignant rhabdoid tumour of the kidney (MRTK), and anaplastic sarcoma of the kidney. Demographic characteristics, treatment strategies, and survival outcomes were analysed. Results: Twenty-five children with NWRTs were identified: CCSK (n = 9), RCC (n = 7), CMN (n = 6), MRTK (n = 2), and anaplastic sarcoma of the kidney (n = 1). At a median follow-up of 107.9 months (range 4.5\u2013181.3 months), overall survival for the cohort was 76%. Overall survival by histology was 100% for CMN, CCSK and anaplastic sarcoma, 43% for RCC, and 0% for MRTK. Treatment strategies varied by histology, with 68% undergoing upfront surgery, 32% receiving neoadjuvant chemotherapy, 60% receiving adjuvant systemic therapy, and 44% receiving radiotherapy. Tumour recurrence occurred in 4\/25 patients (16%), confined to the RCC (3) and CMN (1) subgroups. Seven Event-Free Survival events were observed, comprising three RCC relapses and one RCC progression, one CMN relapse, and two MRTK progression-related deaths. No recurrences occurred in CCSK. Conclusions: NWRTs comprised 17.5% of all paediatric renal tumours diagnosed nationally during the study period and demonstrated marked heterogeneity in outcomes according to histological subtype. CMN showed excellent survival with six out of seven requiring surgery alone, whereas MRTK remained associated with dismal outcomes despite multimodal therapy. These national data support histology-driven, risk-adapted management and highlight the importance of continued international collaboration to improve outcomes in NWRTs.<\/jats:p>","DOI":"10.3390\/children13040575","type":"journal-article","created":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T07:57:21Z","timestamp":1776758241000},"page":"575","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Non-Wilms Renal Tumours in Children: The Republic of Ireland Experience"],"prefix":"10.3390","volume":"13","author":[{"given":"Kris","family":"Hughes","sequence":"first","affiliation":[{"name":"Department of Paediatric Surgery, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-9672-5111","authenticated-orcid":false,"given":"Charles","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Paediatric Surgery, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5982-1944","authenticated-orcid":false,"given":"Michael","family":"Capra","sequence":"additional","affiliation":[{"name":"Department of Paediatric Oncology, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jane","family":"Pears","sequence":"additional","affiliation":[{"name":"Department of Paediatric Oncology, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cormac","family":"Owens","sequence":"additional","affiliation":[{"name":"Department of Paediatric Oncology, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"McDermott","sequence":"additional","affiliation":[{"name":"Department of Pathology, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maureen","family":"O\u2019Sullivan","sequence":"additional","affiliation":[{"name":"Department of Pathology, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sri","family":"Paran","sequence":"additional","affiliation":[{"name":"Department of Paediatric Surgery, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-7626-5238","authenticated-orcid":false,"given":"Israel","family":"Fernandez-Pineda","sequence":"additional","affiliation":[{"name":"Department of Paediatric Surgery, Children\u2019s Health Ireland (CHI) at Crumlin, D12 N512 Dublin, Ireland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,21]]},"reference":[{"key":"ref_1","unstructured":"Marx, A., Chan, J.K., Nonaka, D., Tateyama, H., and Weissferdt, A. (2023). WHO Classification of Tumours. WHO Classification of Tumours Editorial Board. Paediatric Tumours, International Agency for Research on Cancer, WHO Classification of Tumours online. [5th ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.ejca.2016.09.005","article-title":"Biology and treatment of renal tumours in childhood","volume":"68","author":"Brok","year":"2016","journal-title":"Eur. J. Cancer"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3313","DOI":"10.1002\/ijc.33147","article-title":"Incidence of childhood renal tumours: An international population-based study","volume":"147","author":"Nakata","year":"2020","journal-title":"Int. J. Cancer"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e30343","DOI":"10.1002\/pbc.30343","article-title":"Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges","volume":"70","author":"Libes","year":"2023","journal-title":"Pediatr. Blood Cancer"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"282","DOI":"10.1016\/j.ejca.2022.08.021","article-title":"Incidence and survival of paediatric renal tumours in the Netherlands between 1990 and 2014","volume":"175","author":"Schulpen","year":"2022","journal-title":"Eur. J. Cancer"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1038\/s41585-018-0100-3","article-title":"The UMBRELLA SIOP-RTSG 2016 Wilms tumour pathology and molecular biology protocol","volume":"15","author":"Vujanic","year":"2018","journal-title":"Nat. Rev. Urol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e26925","DOI":"10.1002\/pbc.26925","article-title":"ETV6-NTRK3 in congenital mesoblastic nephroma","volume":"65","author":"Vokuhl","year":"2018","journal-title":"Pediatr. Blood Cancer"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1002\/path.3985","article-title":"Characterization of the chromosomal translocation t(10;17)(q22;p13) in clear cell sarcoma of kidney","volume":"227","author":"Stack","year":"2012","journal-title":"J. Pathol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1007\/s10689-021-00229-1","article-title":"Clinical surveillance and genetic testing in rhabdoid tumor predisposition","volume":"20","author":"Fruehwald","year":"2021","journal-title":"Fam. Cancer"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1038\/modpathol.3880006","article-title":"Detection of the ETV6-NTRK3 chimeric RNA","volume":"13","author":"Argani","year":"2000","journal-title":"Mod. Pathol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1002\/gcc.22353","article-title":"BCOR internal tandem duplications in CCSK","volume":"55","author":"Gooskens","year":"2016","journal-title":"Genes Chromosomes Cancer"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"102153","DOI":"10.1016\/j.canep.2022.102153","article-title":"Incidence patterns of childhood non-Wilms renal tumors","volume":"78","author":"Doganis","year":"2022","journal-title":"Cancer Epidemiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"475.e1","DOI":"10.1016\/j.jpurol.2020.05.168","article-title":"Incidence, treatment, and outcomes of primary and recurrent Non-Wilms renal tumors in children","volume":"16","author":"Qureshi","year":"2020","journal-title":"J. Pediatr. Urol."},{"key":"ref_14","first-page":"2724","article-title":"Characteristics and outcome of pediatric renal cell carcinoma","volume":"148","author":"Hol","year":"2021","journal-title":"Int. J. Cancer"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2457","DOI":"10.1002\/cncr.29368","article-title":"Characterization of adolescent and pediatric renal cell carcinoma","volume":"121","author":"Geller","year":"2015","journal-title":"Cancer"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5400","DOI":"10.1002\/cncr.33173","article-title":"Prospective study of pediatric renal cell carcinoma","volume":"126","author":"Geller","year":"2020","journal-title":"Cancer"},{"key":"ref_17","unstructured":"National Cancer Registry Ireland (2023). Cancer Trends 39: Childhood, Adolescent and Young Adult Cancer, NCRI."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Ortiz, M.V., Wens, F.S.P.L., Hong, A.L., Quarello, P., Verschuur, A.C., Tracy, E.T., Daw, N.C., Dome, J.S., Walz, A.L., and Sprokkerieft, J. (2026). Relapsed rhabdoid tumours and other non-nephroblastoma childhood and adolescent kidney tumours: Perspectives from the HARMONICA collaboration. Nat. Rev. Urol.","DOI":"10.1038\/s41585-025-01117-4"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1007\/s00268-011-1410-2","article-title":"Pediatric non-Wilms\u2019 renal tumors: A third world experience","volume":"36","author":"Saula","year":"2012","journal-title":"World J. Surg."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.pedneo.2013.09.007","article-title":"Malignant renal tumors in childhood: Report of 54 cases treated at a single institution","volume":"55","author":"Jaing","year":"2014","journal-title":"Pediatr. Neonatol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1038\/bjc.2014.291","article-title":"Treatment and outcome of patients with relapsed clear cell sarcoma of the kidney: A combined SIOP and AIEOP study","volume":"111","author":"Gooskens","year":"2014","journal-title":"Br. J. Cancer"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1002\/path.4693","article-title":"Mutually exclusive BCOR internal tandem duplications and YWHAE-NUTM2 fusions in clear cell sarcoma of kidney: Not the full story","volume":"238","author":"Kenny","year":"2016","journal-title":"J. Pathol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1007\/s11701-025-02473-4","article-title":"Outcomes of robotic-assisted surgery for pediatric renal tumors: A systematic review","volume":"19","author":"Alansari","year":"2025","journal-title":"J. Robot Surg."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Feng, J., Yang, W., Qin, H., Xu, J., Liu, S., Han, J., Li, N., He, L., and Wang, H. (2023). Clinical application of indocyanine green fluorescence imaging navigation for pediatric renal cancer. Front. Pediatr., 11.","DOI":"10.3389\/fped.2023.1108997"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e260600","DOI":"10.1136\/bcr-2024-260600","article-title":"Preoperative three-dimensional modelling and virtual reality planning aids nephron sparing surgery in a child with bilateral Wilms tumour","volume":"17","author":"Banerjee","year":"2024","journal-title":"BMJ Case Rep."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1038\/modpathol.2017.100","article-title":"Anaplastic sarcomas of the kidney are characterized by DICER1 mutations","volume":"31","author":"Wu","year":"2018","journal-title":"Mod. Pathol."}],"container-title":["Children"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9067\/13\/4\/575\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T08:32:25Z","timestamp":1776760345000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9067\/13\/4\/575"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,21]]},"references-count":26,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["children13040575"],"URL":"https:\/\/doi.org\/10.3390\/children13040575","relation":{},"ISSN":["2227-9067"],"issn-type":[{"value":"2227-9067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,21]]}}}