Metastatic intracranial hemangiopericytoma: The role of octreotide and PET imaging in diagnosis, pre-treatment and follow-up evaluation

Learning Objectives 1. Discuss the radiologic and pathologic characteristics of metastatic hemangiopericytoma seen with somatostatin receptor imaging, FDG-PET, and MRI and relate it to other rare reports of HPC in the literature. 2. Discuss how to exploit these findings to detect recurrence and metastatic disease in patients diagnosed with HPC.

Hemangiopericytomas (HPC) are rare tumors which closely mimic meningiomas radiologically, including their appearance on MRI. However, in contrast to meningiomas, HPCs have a relatively high incidence of local recurrence and distant metastases, manifesting the need for sensitive non-invasive methods of detection that efficiently image the entire body. We present a rare case of right optic nerve sheath HPC that was initially diagnosed as a meningioma, but had demonstrated multiple local recurrences over a 20 year period. We found that similar to meningiomas, HPC was 111In-Pentatreatide avid on SPECT and only mildly took up FDG. Furthermore, we identified a previously unknown distant metastasis in the thoracic spine that was impinging on the spinal cord. We detail the radiologic and pathologic characteristics of this case seen with somatostatin receptor imaging, FDG-PET, and MRI and relate it to other rare reports of HPC in the literature. Importantly, we discuss how to exploit these findings to detect recurrence and metastatic disease in patients diagnosed with HPC