A chance to cut is a chance to cure: complete resection of an atypical neurofibroma prevents further progression to malignancy.

Plexiform neurofibromas are the hallmark of neurofibromatosis type 1 (NF1) and significantly contribute to the overall burden of disease. While surgical excision has long been the only available therapy, the MEK inhibitor (MEKi) selumetinib has been approved as a non-surgical treatment option for these tumors in 2020 (USA) and 2021 (Europe), respectively. However, selumetinib will result in tumor shrinkage only after several months of therapy and might not prevent malignant transformation of a plexiform neurofibroma that occurs with a frequency of 10-15%. Here, we demonstrate that surgical excision might be the therapy of choice in some plexiform neurofibromas despite the availability of MEKi therapy.

Treatment of Plexiform Neurofibromas with MEK Inhibitors: First Results with a New Therapeutic Option.

Neurofibromatosis type-1 (NF1)-associated plexiform neurofibromas (PN) are peripheral nerve sheath tumors that can significantly affect the quality of life. Until recently, surgery was the only treatment for these tumors. However, in most cases, surgery cannot achieve complete tumor removal and carries a high risk of postoperative deficits. Therefore, the recent approval of the MEK inhibitor selumetinib for the treatment of NF1-associated PN provides a long-awaited novel therapeutic option. Here, we report our experience with MEK inhibitor treatment in 12 pediatric NF1 patients with inoperable symptomatic PN. Eight patients received trametinib (median therapy duration 12.13 months and range 4-29 months), and four patients received selumetinib (median therapy duration 6.25 months and range 4-11 months). Volumetric magnetic resonance imaging (MRI) after 6 months of treatment was available for seven trametinib patients (median tumor volume reduction of 26.5% and range 11.3-55.7%) and two selumetinib patients (21.3% tumor volume reduction in one patient and +3% tumor volume change in the other one). All patients reported clinical benefits such as improved range of motion or reduced disfigurement. Therapy-related adverse events occurred in 58.3% of patients and mainly consisted of skin toxicity, paronychia, and gastrointestinal symptoms. Two patients discontinued trametinib treatment after 14 and 29 months when severe skin toxicity occurred and no further reduction of tumor size was observed. In one patient, discontinuation of therapy resulted in a 27.2% tumor volume increase as demonstrated on volumetric MRI 6 months later. Our data show that MEK inhibition is a novel therapeutic approach for inoperable PN with promising results and a manageable safety profile.

Axis fracture due to giant cranial AVM.

Cerebral arteriovenous malformations (AVMs) are a vascular anomaly consisting of a bundle of direct connection of arteries and veins. AVMs clinical expression ranges from complete asymptomatic, and thus incidentally found, to life threatening with rupturing and bleeding. In this wide spectrum, osteolysis is considered as a rare complication of interosseous AVMs, and only few cases of mandible and maxilla osteolysis have been reported. We present, herein, a case of an intracranial AVM, which has caused in the course of the time an osteolysis of the dens and axis.

Non-enhanced MR imaging for preinterventional assessment of the angioarchitecture in vein of Galen malformations.

BACKGROUND AND PURPOSE: Endovascular treatment of vein of Galen malformations (VGMs) requires sufficient preceding MR imaging. Standardized, preinterventional, non-invasive imaging has not been established. Our study is the first to examine the role of a dedicated, standardized, non-invasive imaging protocol in the evaluation of VGM angioarchitecture by non-contrast MRI/MR angiography. MATERIALS AND METHODS: We retrospectively evaluated a consecutive series of VGM patients who underwent a 1.5 T MRI protocol, including standard T2 weighted images (T2WI), arterial time of flight (TOF), and thin T2WI without flow compensation (T2OffPh). The primary outcome was the proportion of patients in whom VGM subtypes and all arterial feeders (anterior (AChA) and posterior (PChA) choroidal arteries, pericallosal arteries, basilar tip, and leptomeningeal supply) could be accurately identified compared with a DSA gold standard. RESULTS: A total of 26 VGM patients who underwent 108 studies were used in the statistical analysis. VGM subtype was best seen in axial T2OffPh (92.1%) and TOF (89.8%). AChA feeders were best seen in TOF (86.5%) and axial T2OffPh (72.2%). PChA feeders were best seen in TOF (95.1%) and axial T2OffPh (88.1%). Pericallosal feeders were best seen in axial T2OffPh (95.4%) and TOF (95.1%). Basilar tip feeders were best seen in TOF (90.6%) and axial T2OffPh (88.4%). CONCLUSION: VGM angioarchitecture is best seen in TOF and axial T2OffPh. It can be used as an alternative to global angiographic series.