HAEMANGIOPERICYTOMA

Hemangiopericytoma (HPC) in central nervous system is a rare tumor, his tumorhas a high recurrence rate and the characteristics of extracranial metastases. Objectives:To investigate the clinicopathological features, imaging features, immunohistochemicalphenotype of haemangiopericytoma (HPC) of central nervous system. Design: Hospital basedcrossectional prospective study. Period: From 24th October to 26th October 2012. Setting: FirstPeople’s Hospital of Jining City, China. Methods: The clinical manifestations, imaging features,histopathological and immunohistochemical features were analyzed combining the review of theliterature in one case of central HPC. Results: The Gross examination revealed the size of thetumor was 5cm × 4cm× 1.5cm; the section is gray, medium soft texture, and part of the area hadcapsule. The microscopic examination showed that the tumor cells were abundant and the samesize, showing round, oval or short spindle shape. The cytoplasm was eosinophilic, and part ofit was slightly translucent. The nuclei were ovoid, and the nucleoli were inconspicuous.A lot ofcapillaries lined by endothelial cells were seen in the tumor tissue, and the blood vessels weredilated like “staghorn” in some areas. Immunohistochemistry showed that tumor cells expressedVimentin, CD34, CD99, Bcl-2, PR protein. They didn’t express EMA, SMA, and S-100 protein.The proliferation index of ki-67 is about 4%. Conclusions: The central haemangiopericytomais a rare tumor, having no specific clinical manifestations and imaging features. The finaldiagnosis requires a combination of histopathological and immunohistochemical examination,and it should be differentiated from meningioma, solitary fibrous tumor, hemangioblastoma andmesenchymal chondrosarcoma, etc.