Intracranial Masson Lesion Following Stereotactic Radiosurgery for Treatment of Intracranial Arteriovenous Malformations

Objectives: Masson tumor or intravascular papillary endothelial cell proliferation was first described in 1923. Only a few cases of intracranial Masson tumor have been reported following stereotactic radiosurgery (SRS). We report a series of 6 cases, age range 28-56 years, with intracranial Masson tumor following SRS for treatment of an intracranial arteriovenous malformation (AVM).

Methods: We performed a retrospective case note review, reviewed the imaging, SRS records, and neuropathology specimens following surgical excision.

Results: In our series all patients received Leksell SRS with the periphery of the AVM receiving doses ranging from 22-25 Gy. The time lapse from SRS to a clear enhancing mass appearing on imaging ranged from 5-10 years. Four patients underwent craniotomy and excision of the enhancing lesion for persistent edema and an enlarging cyst resulting in a resolution of symptoms.

Conclusions: SRS is an effective treatment for obliteration of intracranial AVMs.