A 28-year-old lady presented with headache and vomiting since 11/2 years. She complained of difficulty in gripping objects with left upper limb, gait unsteadiness with tendency to sway to the left side, dysarthria and nasal regurgitation on swallowing fluids. On examination, bilateral gaze evoked downbeat nystagmus was present. Gag reflex was sluggish bilaterally but uvula was central. There was drooping of right shoulder and weakness of right sternocleidomastoid. Left cerebellar signs were present with ataxic gait. Bulk and tone of muscles was normal.\nCT [] showed a hyperdense extraxial lesion in left side posterior fossa, compressing brainstem and distorting the 4th ventricle with obstructive hydrocephalus. On MRI [], it appeared iso- to mildly hypointense on T2 weighted images and hyperintense on T1 weighted images without suppression of signal on fat saturated images. The lesion measured 5.4 × 4.2 × 5.34 cms. There was no obvious enhancement on administration of contrast. There was no restriction diffusion. On the anterior aspect of the lesion, just to the left of midline, there was a T1- and T2 hypointense focus that corresponded with slightly increased density on plain CT and showed blooming on SWI (likely calcification). The lesion showed facilitated diffusion. MRS showed a large NAA like peak at 2.02 ppm.\nShe underwent midline suboccipital craniectomy and near total excision of the lesion. Histopathology showed a cyst wall composed of pseudostratified ciliated columnar epithelium (black arrow) with extensive areas of squamous metaplasia suggestive of neuroenteric cyst.
A 17-year-old female patient presented with occasional headache since two years increased since the last three months. On examination, bilateral papilledema was present. No other focal neurological deficits were present.\nMRI [] showed a well-defined CSF-intensity cystic lesion in the region of the fourth ventricle with obstructive hydrocephalus. There were no enhancing solid components. The lesion showed facilitated diffusion. The patient underwent midline suboccipital craniotomy and deroofing of the cyst. Histopathology showed cuboidal or columnar epithelium (pseudostratified at some foci). Based on the immunohistochemical properties, a final diagnosis of neuroenteric cyst was made. Patient did well in the post-operative period with reduction of the hydrocephalus.