title: Primary epithelioid hemangioendothelioma originating in the lower petroclival region: case report.
abstract: BACKGROUND
  We report the first case of primary epithelioid hemangioendothelioma (EH) originating in the lower petroclival region.
  
  
  METHODS
  A 55-year-old female presented with a 45-year history of subclinical atrophy on the right side of her tongue and a 15-year history of hoarseness. Neuroimaging revealed an expansile, homogeneously enhanced intraosseous mass with bony shell and honeycomb configuration in the petroclival region. A right far lateral transcondylar approach was utilized for subtotal removal of the tumor, which demonstrated high vascularity in the petroclival bone. Histopathological and immunohistochemical examination confirmed the diagnosis of EH. Because of the intermediate malignancy, adjuvant gamma knife radiotherapy was performed for the residual mass 5 months after surgery.
  
  
  CONCLUSIONS
  EH rarely occurs in the skull base region. The appearance of surrounding bony structure and rich vascularity are important findings for the differential diagnosis. A far lateral transcondylar approach provides sufficient exposure of the jugular tubercle and lower clivus. Additional radiotherapy may be recommended for residual tumors with a high MIB-1 labeling index.
authors.affiliation: Department of Neurosurgery, Gunma University School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Saito
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Shimaguchi
authors.forename: Hiroya
authors.initials: H
authors.lastname: Fujimaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Kamiya
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakazato
authors.forename: Tomio
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D018323:Hemangioendothelioma, Epithelioid / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000601:surgery; D016634:Radiosurgery; D019292:Skull Base Neoplasms / Q000473:pathology / Q000601:surgery*