title: Pathological Evaluation of Radiation-Induced Vascular Lesions of the Brain: Distinct from De Novo Cavernous Hemangioma.
abstract: OBJECTIVE
  We aimed to evaluate the histologic and radiologic findings of vascular lesions after stereotactic radiosurgery (SRS) categorized as radiation-induced cavernous hemangioma (RICH).
  
  
  METHODS
  Among 89 patients who underwent neurosurgery for cavernous hemangioma, eight RICHs from 7 patients and 10 de novo CHs from 10 patients were selected for histopathological and radiological comparison.
  
  
  RESULTS
  Histologically, RICHs showed hematoma-like gross appearance. Microscopically, RICH exhibited a hematoma-like area accompanied by proliferation of thin-walled vasculature with fibrin deposits and infiltrating foamy macrophages. In contrast, CHs demonstrated localized malformed vasculature containing fresh and old clotted blood on gross examination. Typically, CHs consisted of thick, ectatic hyalinized vessels lined by endothelium under a light microscope. Magnetic resonance imaging of RICHs revealed some overlapping but distinct features with CHs, including enhancing cystic and solid components with absence or incomplete popcorn-like appearance and partial hemosiderin rims.
  
  
  CONCLUSIONS
  Together with histologic and radiologic findings, RICH may result from blood-filled space after tissue destruction by SRS, accompanied with radiation-induced reactive changes rather than vascular malformation. Thus, the term "RICH" would be inappropriate, because it is more likely to be an inactive organizing hematoma rather than proliferation of malformed vasculature.
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yoon Jin
authors.initials: YJ
authors.lastname: Cha
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji Hae
authors.initials: JH
authors.lastname: Nahm
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Ko
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Shin
authors.affiliation: Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Chang
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Nam Hoon
authors.initials: NH
authors.lastname: Cho
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea. paxco@yuhs.ac.
authors.forename: Se Hoon
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology*; D005260:Female; D006392:Hemangioma, Cavernous / Q000150:complications / Q000473:pathology* / Q000601:surgery; D006406:Hematoma / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects; D016896:Treatment Outcome
keywords: Brain; cavernous; central nervous system; hemangioma; radiosurgery