Calcifying pseudoneoplasm of neuraxis

Case contributed by Dr Bruno Di Muzio


None available.

Patient Data

Age: 70-year-old
Gender: Male
Modality: CT

No report data found

Modality: MRI

A heavily calcified mass lesion measuring approximately 2.2 x 1.5 x 1.7 cm arises from the inferior aspect of the fourth ventricle and bulges inferiorly to the craniocervical junction. It protrudes through the foramen of Luschka on the right.There is an mass effect and slight oedema with in the posterior aspect of the lower medulla.The upper cervical cord is pushed towards the left.The lesion demonstrates

contrast enhancement.It lies adjacent to and effaces the medial wall of the intra dural Right vertebral artery. The findings do not suggest that the lesion is a calcified aneurysm of the vertebral artery.When compared to the outside scan

the mass is probably increased slightly in volumeNo other mass lesions are identified.No hydrocephalus.Minor white matter ischaemia are supratentorially.Minor degenerative changes are noted within the cervical spine.

Conclusion: Heavily calcified mass lesion arising from the inferior aspect of the fourth ventricle and causing mild mass-effect upon the posterior aspect of the medulla and upper cervical cord.

The most likely diagnosis is ependymoma. Meningioma, calcified subependymoma are thought unlikely.

Modality: Pathology

MACROSCOPIC DESCRIPTION: 1. "Brain tissue": Two fragments of gritty fawn tissue up to 8mm. 2. "Brain tumour": Red and pink fragment tissue 1mm aggregate. 3. "Posterior fossa brain tumour": Red and pink fragment tissue 25x10 x10mm aggregate. A1. 

MICROSCOPIC DESCRIPTION: 1-3: Paraffin sections show multiple tissue fragments in which there is widespread deposition of crystalline partially calcified material, much of which is strongly birefringent. In many areas, deposits are surrounded by a population of spindle cells with moderate membrane immunostaining for epithelial membrane antigen (EMA). No perinuclear dot EMA reactivity is seen. The spindle cells are mixed with a lymphohistiocytic cell infiltrate. No immunostaining for GFAP, synaptophysin or progesterone receptor (PgR) is seen. Nuclear Topoisomerase staining is seen in scattered inflammatory cells.The features are of calcifying pseudotumour of the neuraxis (CAPNON).

DIAGNOSIS: 1-3: Craniocervical lesion: Calcifying pseudotumour of the neuraxis (CAPNON).

Case Discussion

Calcifying pseudo neoplasm of the neuraxis or CAPNON corresponds to a rare non-neoplastic non-inflammatory heavily calcified discrete intraparenchymal or extra-axial lesions of CNS.

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Case Information

rID: 44076
Case created: 5th Apr 2016
Last edited: 6th Apr 2016
Inclusion in quiz mode: Included

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