Posterior fossa calcifying pseudoneoplasm of the central nervous system

Case report

Restricted access

Calcifying pseudoneoplasms of the neuraxis are rare, poorly understood masses that may arise throughout the CNS. Although these lesions are generally considered benign and noninfiltrative, reports exist that document growth of these masses on serial plain radiographs. The authors report a case of a posterior fossa calcifying pseudoneoplasm of the neuraxis demonstrating interval development of peritumoral edema on serial MRI. Their findings suggest that these lesions may sometimes behave in a more aggressive manner than commonly thought.

Abbreviations used in this paper:CAPNON = calcifying pseudoneoplasm of the neuraxis; EMA = epithelial membrane antigen.

Article Information

Address correspondence to: Kiarash Shahlaie, M.D., Ph.D., Department of Neurological Surgery, University of California Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, California 95817. email:

Please include this information when citing this paper: published online February 8, 2013; DOI: 10.3171/2013.1.JNS121755.

© AANS, except where prohibited by US copyright law.



  • View in gallery

    Axial T2-weighted MR images of the posterior fossa obtained 38 months preoperatively (A and B), immediately preoperatively (C and D), and immediately postoperatively (E and F).

  • View in gallery

    Computed tomography scans of the posterior fossa obtained preoperatively (A and B), immediately postoperatively (C and D), and at 4 months postoperatively (E and F).

  • View in gallery

    Chondromyxoid matrix with palisade of pleomorphic epithelioid cells and chronic inflammatory infiltrates. H & E, original magnification ×40 (left) and ×200 (right).



Aiken AHAkgun HTihan TBarbaro NGlastonbury C: Calcifying pseudoneoplasms of the neuraxis: CT, MR imaging, and histologic features. AJNR Am J Neuroradiol 30:125612602009


Albu GDeák GMencser ZVajtai I: [Fibro-osseous lesion of the central nervous system.]. Orv Hetil 142:116511672001. (Hungarian)


Bertoni FUnni KKDahlin DCBeabout JWOnofrio BM: Calcifying pseudoneoplasms of the neural axis. J Neurosurg 72:42481990


Chang HPark JBKim KW: Intraosseous calcifying pseudotumor of the axis: a case report. Spine (Phila Pa 1976) 25:103610392000


Fletcher AMGreenlee JJChang KESmoker WRKirby PAO'Brien EK: Endoscopic resection of calcifying pseudoneoplasm of the neuraxis (CAPNON) of the anterior skull base with sinonasal extension. J Clin Neurosci 19:104810492012


Garen PDPowers JMKing JSPerot PL Jr: Intracranial fibroosseous lesion. Case report. J Neurosurg 70:4754771989


Ghosal NFurtado SVGupta KHegde AS: Fibro-osseous lesion of the pineal region resembling osteoblastoma: a case report. Neuropathology 31:1581612011


Hodges TRKarikari IONimjee SMTibaleka JFriedman AHCummings TJ: Calcifying pseudoneoplasm of the cerebellopontine angle: case report. Neurosurgery 1 Suppl Operative69:onsE117onsE1202011


Jun CBurdick B: An unusual fibro-osseous lesion of the brain. Case report. J Neurosurg 60:130813111984


Mohapatra IManish RMahadevan APrasad CSampath SShankar SK: Calcifying pseudoneoplasm (fibro osseous lesion) of neuraxis (CAPNON)—a case report. Clin Neuropathol 29:2232262010


Montibeller GRStan ACKrauss JKNakamura M: Calcifying pseudoneoplasm of the inferior colliculus: an unusual location for a rare tumor: case report. Neurosurgery 65:E1005E10062009


Park PSchmidt LAShah GVTran NKGandhi DLa Marca F: Calcifying pseudoneoplasm of the spine. Clin Neurol Neurosurg 110:3923952008


Qian JRubio APowers JMRosenblum MKPilcher WHShrier DA: Fibro-osseous lesions of the central nervous system: report of four cases and literature review. Am J Surg Pathol 23:127012751999


Rhodes RHDavis RL: An unusual fibro-osseous component in intracranial lesions. Hum Pathol 9:3093191978


Rodriguez FJScheithauer BWFourney DRRobinson CA: Ependymoma and intraparenchymal calcifying pseudoneoplasm of the neural axis: incidental collision or unique reactive phenomenon?. Acta Neuropathol 115:3633662008


Shrier DAMelville DMillet DQian JMillet DNelson C: Fibro-osseous lesions involving the brain: MRI. Neuroradiology 41:18211999


Smith DMBerry AD III: Unusual fibro-osseous lesion of the spinal cord with positive staining for glial fibrillary acidic protein and radiological progression: a case report. Hum Pathol 25:8358381994


Tatke MSingh AKGupta V: Calcifying pseudoneoplasm of the CNS. Br J Neurosurg 15:5215232001


Tsugu HFukushima TTakeno Y: Calcifying pseudotumor of the neural axis—case report. Neurol Med Chir (Tokyo) 39:7627651999




All Time Past Year Past 30 Days
Abstract Views 83 83 30
Full Text Views 189 189 14
PDF Downloads 144 144 5
EPUB Downloads 0 0 0


Google Scholar