ID #283 Primary central nervous system nephroblastoma in a pediatric patient: A case report
Margit Mikkelsen, Matthew Krasin, Kelsey Bertrand, Khrystyna Zapotochna, Soniya Pinto, Jason Chiang, Selene Koo, Daniel MoreiraAbstract
Background
Nephroblastoma is the most common primary childhood renal cancer. Rarely, nephroblastoma has been reported in the central nervous system (CNS) in association with retroperitoneal extension or as metastatic disease. We report a case of primary CNS nephroblastoma without an extra-CNS component.
Case Discussion
A six-year-old female with congenital spinal dysraphism presented with progressive gait alteration. Spinal imaging revealed an intradural, extramedullary spinal mass spanning L1-L4. She underwent subtotal resection, and pathology revealed a primitive epithelial and mesenchymal tumor with primordial glomerular structures, focal rhabdomyoblastic differentiation, and nuclear SALL4, PAX8, and WT1 immunoreactivity. Methylation profiling did not match a CNS tumor entity. The tumor showed segmental chromosome 1 loss. The constellation of histologic and immunophenotypic findings led to the diagnosis of nephroblastoma. Staging confirmed the absence of metastatic or extra-CNS disease. She was treated as a stage III nephroblastoma with chemoradiation as per AREN0532 with nine cycles of dactinomycin, doxorubicin, vincristine, and 21.6 GyRBE focal proton radiotherapy that included the initial resection cavity (10.8 GyRBE) with a boost to areas of residual disease (21.6 GyRBE). At 21 months off therapy, due to frequent headaches, imaging was obtained, which identified a new hypercellular, heterogeneously enhancing right suprasellar mass infiltrating the right mesial temporal lobe. A biopsy confirmed recurrence of primary CNS nephroblastoma. Staging evaluation showed no evidence of additional CNS or extra-CNS disease. She received a total of 8 cycles of ifosphamide, carboplatin, and etoposide, alternating with cyclophosphamide and topotecan, as per AREN1921, incorporating craniospinal proton irradiation (23.4 GyRBE) with a boost to the residual suprasellar tumor (45 GyRBE). Six months after completion of second-line therapy, there is no evidence of progression.
Conclusions
This case illustrates an exceptionally rare primary CNS nephroblastoma. Rare cases such as these require comprehensive pathologic testing and coordinated multi-disciplinary treatment spanning neuro-oncology and solid tumor teams.