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 neck pain since two weeks which was aggravated by exercise and neck movements. She developed weakness of limbs for one week which started in left upper limb and then evolved to involve all four limbs. She also complained of numbness in both upper limbs and urgency of micturation. On neurological examination, tone was mildly decreased in both upper limbs and increased in both lower limbs. Power was 2/5 in left upper limbs and 4/5 in other limbs. Deep tendon reflexes were absent in upper limbs and exaggerated in lower limbs. Pain and touch sensation decreased by 30% below C2 level and vibration sense lost below T2 level.\nMRI [] showed a well circumscribed extra-axial cystic lesion of 3 × 1.8 × 2.4 cm size noted anterior and to the right of medulla extending through foramen magnum into upper cervical canal. It was hyperintense on T1 and T2 weighted images with no diffusion restriction. On right side hypoglossal nerve was displaced laterally by lesion.\nShe underwent suboccipital craniectomy and total excision of the lesion via right lateral approach. Histopathology showed a cyst wall is lined by cuboidal and columnar epithelium with goblet cells (arrow) suggestive of a neuroenteric cyst.\nPostoperatively, patient's power improved to 4/5 in all 4 limbs.