Primary haemangiopericytoma outside muscle cone in fossa orbitalis: a case report and review.

PURPOSE: Orbital haemangiopericytoma (HPC) is a rare tumor with great histological variability and unpredictable clinical and biological behavior. The precise cell type origin is uncertain.

METHOD: A case report is provided.

RESULTS: A 24-year-old male patient visited an ophthalmologist because of proptosis, strabismus, and movement limitation of the right eye one year ago. These symptoms worsened rapidly. Histopathology, MRI methods and microscopy coil were applied to study the features of HPC. The tumor was removed and the histological examination revealed that it was a primary HPC of the orbit.

CONCLUSION: MRI determined the size, location, circumscription, morphological detail, growth pattern, and relationship between masses and surrounding tissues. The genesis location of this HPC was rare, and its internal morphological characters were different from cases reported in the literature. The new type of microscope showed more details of tumor MR image characters objectively.