Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
Sign up to receive an email alert when a new Case of the Week is posted.
November 12, 2012
(Giant) Hemangiopericytoma
- Hemangiopericytomas (HPC) are aggressive hypervascular neoplasms with sarcomatous characteristics arising from pericytic cells.
- The clinical and pathological heterogeneity of HPC makes diagnosis challenging.
- The histopathology of HPC is characterized by tightly packed cells that grow around ramifying, thin-walled, endothelium-lined vascular channels ranging from larger sinusoidal spaces to small capillaries. The classic vascular pattern of HPC has been described as "stag horn" or "antler-like" in configuration.
- Key Diagnostic Features: CT: A hyperdense, inhomogeneous mass with intensive enhancement after contrast administration is seen. Although mimicking intracranial meningiomas, the dural tail sign is infrequently observed in HPC. HPC tends to erode bone, but reactive hyperostosis or intra-tumoral calcification has never been reported. MRI: An inhomogeneous tumour matrix is seen with low-to-intermediate T1 and intermediate-to-high T2 signal intensities. Prominent internal signal voids and marked gadolinium enhancement are typically found. On angiography, dual vascularisation of the external and internal carotid and vertebral arteries, respectively, is often encountered. Intensive tumor enhancement by multiple "corkscrew" feeders is described.
- DDx: glomus tumour; solitary fibrous tumour; leiomyomas; leiomyosarcoma; infantile myofibroma; infantile fibrosarcoma; monophasic synovial sarcoma; mesenchymal chondrosarcoma; and myopericytoma
- Rx: embolization and excision