Ossified choroid plexus papilloma of the fourth ventricle: Elucidation of the mechanism of osteogenesis in benign brain tumors Case report

Sunil Manjila, Erin Miller, Amad Awadallah, Shunichi Murakami, Mark L. Cohen, Alan R. Cohen

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


True ossification within benign brain tumors is rare, and the molecular mechanism for this process is poorly understood. The authors report a case of ossified choroid plexus papilloma (CPP) and analyze it to help elucidate the underlying molecular basis of osteogenesis in benign brain tumors. A 21-year-old man presented with headache and depression that progressed over years. Computed tomography, MRI, and angiography demonstrated a large heavily calcified fourth ventricular tumor with a vascular blush and no hydrocephalus. The tumor was resected and was found to be an ossified CPP. Immunohistochemical staining for VEGF, Sox2, BMP-2, osterix, osteopontin, and osteocalcin was performed in an attempt to elucidate the mechanism of bone formation. The tumor was extensively ossified with mature bone trabeculae. Immunostaining for VEGF was positive. Additional staining showed the presence of osteocalcin in this ossified tumor but not in samples of nonossified CPPs collected from other patients. Staining for osterix and osteopontin was equivocally positive in the ossified CPP but also in the nonossified CPPs examined. The presence of osteocalcin in the ossified CPP demonstrates that there is true bone formation rather than simple calcification. Its appearance within cells around the trabeculae suggests the presence of osteoblasts. The presence of osterix suggests that a pluripotent cell, or one that is already partially differentiated, may be differentiated into an osteoblast through this pathway. This represents the first systematic immunohistochemical analysis of osteogenesis within choroid plexus tumors.

Original languageEnglish (US)
Pages (from-to)13-20
Number of pages8
JournalJournal of Neurosurgery: Pediatrics
Issue number1
StatePublished - Jul 1 2013
Externally publishedYes


  • Bone morphogenetic protein-2
  • Brain tumor
  • Choroid plexus papilloma
  • Fourth ventricle
  • Oncology
  • Ossification
  • Osteocalcin
  • Osteopontin
  • Osterix
  • VEGF

ASJC Scopus subject areas

  • Surgery
  • Pediatrics, Perinatology, and Child Health
  • Clinical Neurology


Dive into the research topics of 'Ossified choroid plexus papilloma of the fourth ventricle: Elucidation of the mechanism of osteogenesis in benign brain tumors Case report'. Together they form a unique fingerprint.

Cite this