Gain-of-function mutations in the beta-catenin gene ( CTNNB1 ) drive genomic instability within different cancers. However, it is unclear whether alterations in beta-catenin signaling can still lead to chromosomal rearrangements in neoplasms without metastatic potential. Here, we report a unique case, whereby a desmoid tumor of the scalp contains a missense mutation in CTNNB1 . This mutation is located at the T41 phosphorylation site-previously reported to be necessary for proper beta-catenin degradation. Online database analysis then revealed that our mutation is likely causative of many different cancers and also absent in the healthy public. Karyotyping of the desmoid tumor cells then showed complex chromosomal changes in 16 out of 20 cells examined. To treat this patient, we surgically removed both the neoplasm and underlying calvarium and then successfully reconstructed the skull and scalp. Taken together, our data suggest that increased beta-catenin signaling can lead to genomic instability in the absence of metastatic potential.

To update our experience treating benign head-and-neck paragangliomas (PGs) with radiotherapy (RT).
A total of 149 patients with 176 PGs received curative-intent RT; 126 received RT to 1 PG and 23 to 2 or more PGs. The most common dose fractionation schedule was 45 Gy/25 once-daily fractions/5 weeks which was used to treat 147 PGs (83.5%) in 123 patients (82.6%). Patients were followed with physical examination and CT/MRI. The median follow-up for all patients was 10.6 years (range, 0.2-50.4 years); the median follow-up for surviving patients was 11.1 years (range, 0.2-50.4).
The 5-year, 10-year, and 15-year outcomes were: local control, 99%, 96%, and 95%; distant metastasis-free survival, 99%, 99%, and 99%; cause-specific survival, 98%, 98%, and 98%; and overall survival, 90%, 75%, and 64%, respectively. No patient developed a moderate or severe complication, or a radiation-induced second tumor or malignant transformation of the benign PG.
RT is an effective treatment for head-and-neck PGs with a low risk of complications.