Upfront radiotherapy as part of the multimodal treatment of intravascular papillary endothelial hyperplasia (Masson's tumor) of the neurocranium-a case report and review of the literature.

PURPOSE: Intravascular papillary endothelial hyperplasia (IPEH, "Masson's tumor") is a rare benign tumor of vascular origin. It may occur at various anatomical sites and is often preceded by local stress conditions such as trauma or even stereotactic radiotherapy. The treatment normally requires surgical resection, as tumors are able to grow rapidly and cause symptoms that can limit activities of daily life. METHODS: We present the case of a 77-year-old woman developing IPEH in the left supraorbital skull after facial trauma, leading to rapid mutilating tumor growth and causing loss of functionality of the left eye. Since a surgical approach was initially not possible due to the bleeding risk, local radiotherapy was applied. Because radiotherapy can also be a cause of IPEH, we discuss its use as part of a multimodal treatment strategy based on the available literature. RESULTS: Evidence regarding the optimal treatment of IPEH is limited. Several case reports link its appearance to prior stereotactic radiotherapy. In our case, the application of normofractionated radiotherapy resulted in a stop of tumor growth. After additional necrosectomy, the patient regained functionality of her left eye and was less limited in everyday activities. CONCLUSION: While stereotactic radiotherapy has been linked to the development of IPEH in selected reports, normofractionated radiotherapy achieved meaningful local control in this case and facilitated further surgical treatment.