Vols. Videos

Hemangiopericytoma (HPC)

Last Updated: March 27, 2020

Figure 1: Often appearing as a more aggressive version of a meningioma, hemangiopericytoma is often a complex-appearing extra-axial mass on CT (top row left), with areas of cystic degeneration and hyperdensity reflecting hypercellularity. T2WI (top row right) confirms the extraaxial location with the adjacent CSF cleft. Low T2 signal likely also reflects hypercellularity. Contrast-enhanced image (bottom) demonstrates heterogeneous enhancement of this falx-based lesion. This patient has already had previous resection of their lesion from a left occipital approach.

Figure 2: This hemangiopericytoma demonstrates complexity, cystic change and hyperdensity on CT (top row left). The cystic changes and surrounding edema are even more evident on T2WI (top row right). Avid, heterogeneous enhancement on postcontrast images (bottom) is also typical. This lesion has also invaded the superior sagittal sinus, visible on this coronal contrast-enhanced image.

Basic Description

  • Highly vascular, hypercellular meningeal mesenchymal tumor
  • Fibroblastic sarcoma
  • Synonymous with “solitary fibrous tumor, hemangiocytoma type”

Pathology

  • WHO grade II or III (anaplastic)
  • Arises from smooth muscle pericytes around meningeal capillaries
  • “Staghorn” pattern of malignant cells surrounding blood vessels
  • Hypercellular, increased mitotic index (Ki-67 5-10%)
    • Markedly increased mitoses, necrosis in WHO grade III tumors
  • More aggressive than meningiomas
  • Anaplastic tumors have a tendency for systemic metastases

Clinical Features

  • Adults most commonly afflicted (4th-6th decades of life)
  • Slight male gender predilection
  • Common presenting signs/symptoms: headache
  • Treatment: surgical resection ± pre-surgical embolization due to risk of intra-operative hemorrhage, chemotherapy, XRT
  • Long-term patient monitoring due to delayed local recurrence, metastases
  • Prognosis: 5-year survival >90%

Imaging Features

  • General
    • Lobulated, enhancing extra-axial mass with dural attachment (dural tail)
    • Mimics meningioma but lacks calcification or adjacent calvarial hyperostosis
    • Dural sinus invasion, calvarial erosion may be seen
  • CT

    • Hyperdense extra-axial mass
    • Hypodense peritumoral edema
    • ± Calvarial erosion
    • Heterogeneous, but avid enhancement on contrast-enhanced CT
  • MRI

    • T1WI: heterogeneous signal, ± flow voids
    • T2WI: heterogeneous signal, hyperintense peritumoral edema, ± flow voids
    • T1WI+C: heterogeneous but avid enhancement, ± dural tail
    • MRV: ± dural venous sinus invasion/occlusion

Imaging Recommendations

  • MRI without and with IV contrast; CT to help characterize calvarial invasion

For more information, please see the corresponding chapter in Radiopaedia.

Contributor: Rachel Seltman, MD

DOI: https://doi.org/10.18791/nsatlas.v1.03.01.23

References

Damodaran O, et al. Primary intracranial haemangiopericytoma: comparison of survival outcomes and metastatic potential in WHO grade II and III variants. J Clin Neurosci. 2014;21:1310-1314.

Fountas KN, et al. Management of intracranial meningeal hemangiopericytomas: outcome and experience. Neurosurg Rev. 2006;29:145-153.

Liu G, et al. Intracranial hemangiopericytoma: MR imaging findings and diagnostic usefulness of minimum ADC values. J Magn Reson Imaging. 2013;38:1146-1151.

Louis DN, et al. WHO Classification of Tumours of the CNS: Haemangiopericytoma. Lyon: IARC Press, 2007; 178-180.

Osborn AG, Salzman, KL, Jhaveri MD. Diagnostic Imaging (3rd ed). Philadelphia, PA: Elsevier, 2016.

Sibtain NA, et al. Imaging features of central nervous system haemangiopericytomas. Eur Radiol. 2007;17:1685-1693.

Smith AB, et al. From the radiologic pathology archives: mass lesions of the dura: beyond meningioma-radiologic-pathologic correlation. Radiographics. 2014;34:295-312.

Wu W, et al. Hemangiopericytomas in the central nervous system. J Clin Neurosci. 2009;16:519-523.

Please login to post a comment.

Top