Langerhans Cell Histiocytosis of the Head and Neck: Experience at a Rural Tertiary Referral Center.

Objectives: Retrospectively analyze head and neck Langerhans Cell Histiocytosis at a rural tertiary referral center and compare results with previously published data.

Methods: Electronic health record review was performed from 2003 to 2019. Patients with biopsy proven LCH with primary head and neck involvement were included.

Cancers from Novel -Mutant Mouse Models Provide Insights into Polymerase-Mediated Hypermutagenesis and Immune Checkpoint Blockade.

mutations are a major cause of hypermutant cancers, yet questions remain regarding mechanisms of tumorigenesis, genotype-phenotype correlation, and therapeutic considerations. In this study, we establish mouse models harboring cancer-associated mutations P286R and S459F, which cause rapid albeit distinct time to cancer initiation , independent of their exonuclease activity. Mouse and human correlates enabled novel stratification of mutations into three groups based on clinical phenotype and mutagenicity.

Germline-driven replication repair-deficient high-grade gliomas exhibit unique hypomethylation patterns.

Replication repair deficiency (RRD) leading to hypermutation is an important driving mechanism of high-grade glioma (HGG) occurring predominantly in the context of germline mutations in RRD-associated genes. Although HGG presents specific patterns of DNA methylation corresponding to oncogenic mutations, this has not been well studied in replication repair-deficient tumors. We analyzed 51 HGG arising in the background of gene mutations in RRD utilizing either 450 k or 850 k methylation arrays.

Functional Repair Assay for the Diagnosis of Constitutional Mismatch Repair Deficiency From Non-Neoplastic Tissue.

Purpose: Constitutional mismatch repair deficiency (CMMRD) is a highly penetrant cancer predisposition syndrome caused by biallelic mutations in mismatch repair (MMR) genes. As several cancer syndromes are clinically similar, accurate diagnosis is critical to cancer screening and treatment. As genetic diagnosis is confounded by 15 or more pseudogenes and variants of uncertain significance, a robust diagnostic assay is urgently needed.