Recurrent neurenteric cysts compressing the brainstem

INTRODUCTION

Neurenteric cysts, also referred to as endodermal cysts and enterogenous cysts, are rare lesions of the neuroaxis occurring most frequently within the spinal cord and rarely intracranially. In the literature describing these lesions, examples of intraoperative imaging and cytology preparations are rare to non-existent.

CASE REPORT

A 47-year-old female with a history of posterior fossa neurenteric cysts presented with incontinence and progressive quadriparesis. In 1994, she experienced imbalance and falls, and head imaging revealed a 7 cm posterior fossa cyst which was resected. Another resection was performed in 1997. She developed hydrocephalus, resulting in a ventriculoperitoneal shunt placement with subsequent revisions due to infections and clotting. In the 2 months before presentation, she developed incontinence and progressive quadriparesis. Magnetic resonance imaging showed multiple, expanding, and recurrent neurenteric cysts in the left cerebellomedullary angle and left prepontine cistern compressing the medulla [Figure 1a]. Surgical resection of the cysts was performed, requiring dissection of cyst capsules from the posterior inferior cerebellar artery and cranial nerves. The cysts were clustered like grapes and were pale, white, and adherent to but separable from the medulla and upper cervical spinal cord [Figure 1b].

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Figure 1:: Neurenteric cysts compressing the brainstem. Magnetic resonance imaging demonstrated multiple, nonenhancing, multiolobulated, expanding, and extra-axial recurrent neurenteric cysts compressing the medulla (a). An intraoperative image showing the cysts which were adherent to but separable from the medulla and upper cervical spinal cord (b).

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Intraoperative squash preparations demonstrated sheets of epithelial cells with honeycomb architecture, distinct cell borders, and abundant cytoplasm within a background of mucin [Figure 2a]. Permanent sections revealed neurenteric cysts lined by columnar cells with basally located nuclei with underlying basement membrane and connective tissue stroma. Abundant colloid material was present [Figure 2b]. The patient was later discharged to a skilled nursing facility in stable condition.

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Figure 2:: Cytology and histology of the neurenteric cysts. Intraoperative squash preparation stained with hematoxylin and eosin revealed sheets of epithelial cells with honeycomb architecture, distinct cell borders, and abundant cytoplasm within a background of mucin, ×200 (a). Hematoxylin and eosin-stained permanent sections showing cyst wall lined by columnar epithelium with underlying basement membrane and connective tissue stroma, ×200 (b).

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DISCUSSION

Neurenteric cysts, also referred to as endodermal cysts and enterogenous cysts, are rare lesions comprising 0.7–1.3% of all spinal cord tumors and occurring less frequently within the posterior fossa and cerebral hemispheres.[1,3] Headache is the most common presenting symptom for intracranial neurenteric cysts with extremity weakness and gait disturbance seen less frequently.[1] These cysts are lined by columnar or cuboidal epithelium with goblet cells. The treatment often involves resection and recurrence is common.[4] While neurenteric cysts are generally considered to be benign and slow-growing, rare reports of posterior fossa neurenteric cysts exhibiting rapid expansion or malignant transformation often in the form of adenocarcinoma have been reported.[2,5]

CONCLUSION

Neurenteric cysts are generally considered to be benign and slow-growing though recurrence is common. This case of recurrent intracranial neurenteric cysts includes illustrations of intraoperative macroscopic and cytologic images.