Radiation-Induced Intravascular Papillary Endothelial Hyperplasia in a Cavernous Sinus Hemangioma

Background: Cavernous sinus hemangiomas are benign vascular tumors of the cavernous sinus. Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's angioma is a rare, aberrant thrombus organization occurring independently or in pre-existent lesions, and information on its occurrence in the intracranial region, or its management is sparse. Objective: We aim to describe a case of IPEH occurring in a pre-existing cavernous sinus hemangioma, treated with surgical excision and radiation therapy, providing insight into the appropriate treatment of these tumors and their response to therapy. Materials and Methods: We describe a right cavernous sinus hemangioma, recurring after initial radiation therapy and requiring surgical excision, at which point the presence of IPEH was noted. A sellar recurrence following partial excision was treated with hypofractionated Stereotactic radiotherapy (SRT), and this provided an excellent long-term outcome. Conclusions: Cavernous sinus hemangiomas are treated with surgical excision or primary radiation therapy. IPEH must be looked for in all excised specimens, as there are no radiological features that indicate its presence, and it may resemble the original lesion histologically. When detected, adjuvant radiation must be administered as the IPEH responds well to the use of radiation therapy.