SMARCB1 mutation

This report represents the first known case of ATRT in a young adult patient with Down syndrome, offering unique mechanistic insight into the tumorigenesis of ATRT. Further studies are needed to define an appropriate risk-adapted and standardized therapeutic approach for this patient population.

This case showed a patient with DMT, SMARCB1 mutant with a relatively low Ki-67 proliferation index (less than 1%), clinically combined with typical Parinaud's syndrome. At the same time, the follow-up of this case may provide a better understanding of the prognosis of this specific kind of tumor. https://thejns.org/doi/10.3171/CASE24419.

Mechanistic studies suggest that this missense mutation may abnormally activate the MAPK signaling pathway, which is implicated in the pathogenesis of tumor progression and neurodevelopmental disorders. This is the first reported case of a germline mutation in the SMARCB1 gene associated with both CSS3 and meningioma, thereby expanding the phenotypic spectrum of SMARCB1-related disorders.

Six cycles of the dose-dense methotrexate, vinblastine, adriamycin, and cisplatin-combined chemotherapy were completed after an ultrasound-guided percutaneous biopsy of the renal tumor. After chemotherapy, the size of the original tumor in the right kidney had decreased in size, as well as the other metastatic lesions.

EZH2i also upregulates the expression of full-length LINE-1s, leading to genomic instability and cGAS/STING signaling in a process dependent on reverse transcriptase activity. Co-depletion of dsRNA sensing and cytoplasmic DNA sensing completely rescues the viral mimicry response to EZH2i in SMARCB1-deficient tumors.

Constitutional mosaicism for pathogenic small SMARCB1 variants is recurrent in patients with allegedly sporadic rhabdoid tumors. The clinical implications of such variants need to be determined in larger, prospective cohorts also including detection of structural variants of SMARCB1.

Histologic diagnosis necessitates biopsy, unless in cases of germ cell tumours, particularly germinomas, which can be identified through elevated levels of tumour markers like alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in both cerebrospinal fluid (CSF) and serum. While benign tumours might be effectively treated with radical resection alone, malignant tumours demand additional chemotherapy and radiotherapy following surgical removal.

P1/2, N=231, Recruiting, Novartis Pharmaceuticals | Trial completion date: Oct 2028 --> Jan 2029

Consequently, cancer results not from the loss of SMARCB1 function per se, but rather from DCAF5-mediated degradation of SWI/SNF complexes. These data indicate that therapeutic targeting of ubiquitin-mediated quality-control factors may effectively reverse the malignant state of some cancers driven by disruption of tumour suppressor complexes.

However, after 10 years, a recurrence was detected through magnetic resonance imaging (MRI) and the tumor was reclassified as AT/RT. We discuss the significance of SMARCB1 gene mutations in diagnosing AT/RT and describe our unique treatment approach involving surgery, radiation and anti-PD1 therapy in this patient.

The original diagnosis was usually high-grade non-intestinal-type adenocarcinoma or high-grade myoepithelial carcinoma. A correct diagnosis of these aggressive tumors could lead to improved targeted therapies with potentially better overall disease-specific survival.

Due to progression of all tumors, he was treated medically with both everolimus (10 mg/day) and selumetinib (25 mg/kg twice a day), but he rapidly transitioned to selumetinib monotherapy due to everolimus toxicity. This PR was quantified by the differences in units of intensity in pre- and post-treatment magnetic resonance image. To the best of our knowledge, this is the first reported case for using selumetinib in NF2-associated tumors or ependymomas.