Intracranial Neurenteric Cysts: Imaging and Pathology Spectrum
M.T. Preecea,
A.G. Osborna,
S.S. Chinb and
J.G. Smirniotopoulosc
a Department of Radiology, University of Utah, Salt Lake City, Utah
b Department of Pathology, University of Utah, Salt Lake City, Utah
c Department of Radiology and Nuclear Medicine, Uniformed Services University, Bethesda, Md
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Fig 1. Patient 9. CT myelogram shows a well-delineated ovoid extra-axial mass (white arrow), at the foramen magnum level, associated with midline clefting of a craniovertebral junction fusion anomaly (black open arrow). Bony anomalies are associated with approximately 50% of spinal NE cysts but have rarely been described in intracranial cases.
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Fig 2. Patient 2.
A, Sagittal T1-weighted image demonstrates an ovoid mass (arrows) in the midline anterior to the pontomedullary junction. The cyst is hyperintense to brain parenchyma and CSF (reproduced from Osborn AG, et al, Diagnostic Imaging: Brain, Amirsys/Elsevier, 2004).
B, Axial FLAIR scan in the same patient shows that the mass remains hyperintense and extends from the midline into the right lower cerebellopontine angle.
C, Representative histopathology of a NE cyst showing pseudostratified, ciliated, columnar epithelium, which is poor in mucin-producing cells.
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Fig 3. Patient 3.
A, Axial T1-weighted demonstrates an ovoid mass (arrow) slightly to the left of midline at the level of the pontomedullary junction. It is hyperintense to CSF and isointense to the surrounding brain parenchyma.
B, Axial T2-weighted image in the same patient demonstrates that the cyst is isointense to slightly hyperintense compared with CSF (arrow). Imaging findings are typical for NE cyst.
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Fig 4. Patient 4.
A, Axial T2-weighted scan shows a huge extra-axial cyst (white arrows) with septation (black arrow) that displaces the corpus callosum posteriorly.
B, Axial FLAIR image in the same patient shows that the cyst fluid (open arrows) does not suppress and remains hyperintense compared with CSF. NE cyst was found at surgery. This lesion is unusual because of its supratentorial location and size. The rim of hyperintensity posteromedial to the cyst probably represents compressed brain, not the cyst wall itself, which is a single cell layer. The hyperin- tensity in the center of the lesion was not seen on any other images and is probably an artifact.
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Fig 5. Patient 7. Sagittal postcontrast T1-weighted scan showing a large, well-delineated extra-axial mass (arrows) elevating and displacing the pons and medulla. The mass is slightly hyperintense compared with CSF. Slight rim enhancement is seen posteriorly, where the mass adheres to the brain parenchyma (open arrow). Cyst with watery, slightly cloudy fluid was found at surgery. Microscopic examination showed cyst lining composed of columnar epithelium with goblet cells, typical for NE cyst. Mild inflammatory changes in the cyst wall adjacent to the brain stem were present. Etiology of the rounded hyperintensity superior to the cyst is unexplained; the surgeons found nothing at the operation that clarified its nature. Postoperative changes of a prior occipital decompression for "Chiari 1" malformation are present (reproduced from Osborn AG, et al, Diagnostic Imaging: Brain, Amirsys/Elsevier, 2004).
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Fig 6. Patient 13. Intraoperative photograph of a NE cyst in situ. The cyst is anterior to the brain stem with extension into both cerebellopontine angle cisterns. At surgery, this greenish cyst was found to be adherent to multiple structures.
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Fig 7. Patient 8. Representative histopathology of a NE cyst showing simple columnar to cuboidal epithelium that is rich in mucin-producing cells.
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