Clinical and Molecular Characteristics and Outcome of Cystic Partially Differentiated Nephroblastoma and Cystic Nephroma: A Narrative Review of the Literature
In children presenting with a predominantly cystic renal tumor, the most likely diagnoses
include cystic partially differentiated nephroblastoma (CPDN) and cystic nephroma (CN). Both
entities are rare and limited information on the clinical and molecular characteristics, treatment, and
outcome is available since large cohort studies are lacking. We performed an extensive literature
review, in which we identified 113 CPDN and 167 CN. The median age at presentation for CPDN
and CN was 12 months (range: 3 weeks–4 years) and 16 months (prenatal diagnosis–16 years),
respectively. No patients presented with metastatic disease. Bilateral disease occurred in both entities.
Surgery was the main treatment for both. Two/113 CPDN patients and 26/167 CN patients had
previous, concomitant, or subsequent other tumors. Unlike CPDN, CN was strongly associated with
somatic (n = 27/29) and germline (n = 12/12) DICER1-mutations. Four CPDN patients and one CN
patient relapsed. Death was reported in six/103 patients with CPDN and six/118 CN patients, none
directly due to disease. In conclusion, children with CPDN and CN are young, do not present with
metastases, and have an excellent outcome. Awareness of concomitant or subsequent tumors and
genetic testing is important. International registration of cystic renal tumor cohorts is required to
enable a better understanding of clinical and genetic characteristics
