Atypical teratoid/rhabdoid tumors (AT/RTs) of the central nervous system (CNS) are rare, aggressive, early childhood tumors with unfavorable prognosis. There have been 31 cases reported of children with AT/RT of the CNS and extra CNS primary tumors. In addition to its aggressive tendencies, malignant rhabdoid tumors (MRTs) of the kidney have also shown a common genetic abnormality-inactivating mutation of SMARC B1/INI-gene. We report a 22-month-old male who presented at 15 months of age with metastatic AT/RT of the posterior fossa and synchronous malignant rhabdoid tumor of the left kidney. MRI of the brain demonstrated a midline posterior fossa mass and left renal mass was noted incidentally on imaging of spine. Pathology was consistent with MRT of the kidney and pathogenic variant was found in the tumor sample, specifically SMARCB1 homozygous/biallelic deletion. Patient underwent a subtotal resection of the posterior fossa tumor and subsequent radical resection of the mass on kidney rhabdoid tumor. He was treated as per ACNS033 protocol with 2 cycles of induction with high-dose methotrexate followed by vincristine, cyclophosphamide, cisplatin, and etoposide with complete response followed by three tandem stem cell transplants with thiotepa and carboplatin for which he has been tolerating and responding favorably. Focal radiation therapy to the brain and flank area is planned at end of therapy. In a large series of synchronous AT/RTs reported in 2017 only 3 of the 31 patients were considered long-term survivors. All received a combination of high dose intrathecal or intravenous chemotherapy, total resection of at least one of the tumors, focal radiation, and autologous peripheral blood stem cell transplant. We demonstrated a case with a favorable response with our treatment. Treatment continues to be challenging given the tumor’s rarity and mortality as there are no standardized protocols or randomized controlled trials.

BACKGROUND: Meningiomas are rare primary brain tumors in the pediatric population, associated with multiple genetic mutations. Recent description of mutations in the TRAF7gene, a pro-apoptotic E3 ubiquitin ligase, have been found in up to one quarter of non NF-2 tumors. TRAF is downregulated in human keratinocytes after inhibition of the PI3K/AKT/mTOR signaling. Germ-line mutations in this gene are associated with facial, cardiac malformations, variable intellectual deficiency, and musculoskeletal abnormalities. OBJECTIVE: We report a case of meningiomatosis in an adolescent with TRAF 7 mutation. CASE PRESENTATION: A 17 yo female with complex medical history that includes syndactyly of the left foot, small hands and digits, congenital heart disease, overgrowth of the right lower extremity with lipomatous subcutaneous tumors, connective tissue disorder variant mutation of unknown significance in the gene Col11A2, conductive hearing loss developed meningiomas of both optic nerves requiring decompression and unroofing on two separate occasions, with associated blindness. MRI brain showed bilateral optic nerve sheath enhancement, dysplasia of the corpus callosum, mild hemimegalencephaly, inter-hemispheric fissure 1.5 cm meningioma, bilateral enhancement of internal auditory canals as well as trigeminal and glossopharyngeal nerve, consistent with menigiomatosis. Pathology showed a grade I meningioma with a TRAF7 p.G536S detected by performing a 500 genomic panel (UCSF500). She was started on Everolimus and Bevacizumab. CONCLUSION: Recurrent multiple meningiomas represent a treatment challenge for neuro-oncologists. The evolving understanding of the genetics of these tumors has improved our understanding of their pathogenesis as well as treatment. TRAF 7 mutations are associated with non-NF-2 meningiomas, and distinct phenotypic features. Germ-line testing should be considered in patients with associated malformations, as targeted therapy may improve patient outcomes.

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