HAEMANGIOPERICYTOMA; CLINICOPATHOLOGICAL ANALYSIS OF CENTRAL NERVOUS SYSTEM.

Hemangiopericytoma (HPC) in central nervous system is a rare tumor, his tumor has a high recurrence rate and the characteristics of extracranial metastases. Objectives: To investigate the clinicopathological features, imaging features, immunohistochemical phenotype of haemangiopericytoma (HPC) of central nervous system. Design: Hospital based crossectional prospective study. Period: From 24th October to 26th October 2012. Setting: First People's Hospital of Jining City, China. Methods: The clinical manifestations, imaging features, histopathological and immunohistochemical features were analyzed combining the review of the literature in one case of central HPC. Results: The Gross examination revealed the size of the tumor was 5cm × 4cm × 1.5cm; the section is gray, medium soft texture, and part of the area had capsule. The microscopic examination showed that the tumor cells were abundant and the same size, showing round, oval or short spindle shape. The cytoplasm was eosinophilic, and part of it was slightly translucent. The nuclei were ovoid, and the nucleoli were inconspicuous. A lot of capillaries lined by endothelial cells were seen in the tumor tissue, and the blood vessels were dilated like "staghorn" in some areas. Immunohistochemistry showed that tumor cells expressed Vimentin, 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 haemangiopericytoma is a rare tumor, having no specific clinical manifestations and imaging features. The final diagnosis requires a combination of histopathological and immunohistochemical examination, and it should be differentiated from meningioma, solitary fibrous tumor, hemangioblastoma and mesenchymal chondrosarcoma, etc. [ABSTRACT FROM AUTHOR]