Intraspinal Dissemination and Local Recurrence of an Intracranial Hemangiopericytoma

Background Hemangiopericytomas (HPCs) are rare vascular tumors that resemble meningiomas on imaging and have a high rate of local recurrence and metastases. There remains a paucity of data to guide management decisions of intraspinal dissemination of HPCs in the literature, and none specifically related to anaplastic HPCs. Case Description We report a case of a 34-year-old woman with locally and distantly recurrent anaplastic HPC (World Health Organization grade III). She initially presented with tinnitus in her right ear. A well-circumscribed, contrast-enhancing lesion was identified in the right cerebellopontine angle. Treatment consisted of subtotal resection and postoperative radiation therapy (RT) to a dose of 60 Gy in 30 fractions. After a 3-year disease-free interval, 7 lesions recurred intra- and extracranially. The extracranial lesions were drop metastases of the original HPC through the cerebrospinal fluid into the spinal canal. Of note, fluorodeoxyglucose positron emission tomography (PET)/computed tomography scan was not sensitive enough to detect these new lesions. The intracranial recurrence was on the edge of the prior radiotherapy field, representing a marginal failure having received less than 50 Gy. The intracranial recurrences were treated with salvage gamma knife stereotactic radiosurgery (SRS) with local control. She underwent intradural extramedullary hemilaminectomy of a thoracic spine metastasis followed by fractionated proton beam therapy (PBT) with a boost to unresected lesions. Within a few months of PBT, she became pregnant. Pregnancy did not affect recurrence or ameliorate tumor growth. Conclusions This case report discusses the role genetics, adjuvant RT, SRS, magnetic resonance imaging, and PET scan played in this unique clinical scenario of anaplastic HPC.