title: Intracranial extension of adenoid cystic carcinoma: potential involvement of EphA2 expression and epithelial-mesenchymal transition in tumor metastasis: a case report.
abstract: BACKGROUND
  Adenoid cystic carcinoma is a malignant epithelial tumor derived from salivary glands and tends to invade the surrounding structures including nervous system. We present a case of adenoid cystic carcinoma with intracranial extension and propose a novel molecular mechanism of adenoid cystic carcinoma metastasis.
  
  
  METHODS
  A 29-year-old Japanese male presented with left trigeminal nerve disturbance. Neuroimaging revealed a tumor located at the right middle cranial and infratemporal fossa. The tumor was removed via a subtemporal extradural and infratemporal fossa approach and histologically diagnosed as adenoid cystic carcinoma. Radiological and operative findings confirmed a perineural spread of the tumor along the mandibular nerve. Immunohistochemical analyses of molecular consequences in this case were performed for better understanding of the biological processes associated with adenoid cystic carcinoma metastasis. First, the neoplastic cells were not immunoreactive for E-cadherin, an epithelial marker, but for vimentin, a mesenchymal marker, suggesting changes in cell phenotype from epithelial to mesenchymal states. Correspondingly, immunoreactivity of transcriptional factors, such as Slug, Twist, matrix metalloproteinase-2 and -9, which are involved in epithelial-mesenchymal transition, were observed. Second, elevated expression of EphA2 receptor, not ephrin-A1, was notable in the neoplastic cells, suggesting morphological changes reminiscent of epithelial-mesenchymal transition and ligand-independent promotion of tumor cell migration and invasion.
  
  
  CONCLUSIONS
  We report a case of adenoid cystic carcinoma with perineural spread and provide the first published evidence that EphA2 expression without ephrin-A1 and epithelial-mesenchymal transition might play important roles in adenoid cystic carcinoma progression.
authors.affiliation: Department of Neurological Surgery, Wakayama Medical University School of Medicine, Kimiidera 811-1, Wakayama 641-0012, Japan. junfukai@wakayama-med.ac.jp.
authors.forename: Junya
authors.initials: J
authors.lastname: Fukai
authors.forename: Koji
authors.initials: K
authors.lastname: Fujita
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yamoto
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sasaki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Uematsu
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Nakao
mesh_terms: D003528:Carcinoma, Adenoid Cystic / Q000378:metabolism / Q000473:pathology*; D058750:Epithelial-Mesenchymal Transition; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009362:Neoplasm Metastasis; D010525:Peripheral Nerves / Q000378:metabolism / Q000473:pathology*; D036104:Receptor, EphA2 / Q000378:metabolism; D019292:Skull Base Neoplasms / Q000378:metabolism / Q000473:pathology*; D055815:Young Adult
chemical_list: D036104:Receptor, EphA2