A rare presentation of a pediatric neurenteric cyst as an intra-axial pontine lesion: A case report with a 5-year follow-up

A ventral brainstem neurenteric cyst - A case report and review of the pre-brainstem location

Background

Neurenteric cysts are uncommon, benign endoderm-derived lesions that result from aberrant embryologic development of the notochord. They are typically located in the intradural extramedullary spinal cord and rarely located intracranially. Contrary to spinal-located cysts, intracranial cysts are rarer in the pediatric population. Clinically, they may present with symptoms of mass effect, or they can be incidentally discovered.

Case Description

A 10-year-old healthy female child presented with recurrent headaches. The physical and neurological examination was unremarkable. Brain magnetic resonance imaging (MRI) showed a well-demarcated lesion anterior to the pontomedullary junction with striking T1 and T2/T2 fluid-attenuated inversion recovery high-signal intensity and a small rounded nodule within of low signal on T1, T2, and T2*. On initial conservative strategy with serial brain MRI, there was a progressive enlargement of the lesion with significant mass effect on the brainstem. The patient underwent a right retrosigmoid craniotomy, and the cyst wall was fenestrated and drained. Part of the cyst wall and the solid nodule were adherent to the brainstem and basilar artery and were not removed. The histologic findings were consistent with the diagnosis of a benign endodermal cyst. The postoperative period was uneventful.

Conclusion

We report a successful surgical treatment of this rare congenital cyst located in the ventral brainstem. We present pre-and post-operative imaging findings, intraoperative microscopic images of the procedure, and a brief review of relevant clinical literature on the topic.

Enigmatic echoes: Exploring brainstem neurenteric cysts - A case series and literature review

INTRODUCTION AND IMPORTANCE

Neurenteric cysts (NCs) are rare congenital anomalies within the central nervous system, originating from the endodermal layer due to inappropriate embryonic notochordal plate and endoderm separation. Despite constituting a minute fraction of CNS tumors, their diverse clinical presentations and brainstem occurrence pose diagnostic challenges.

CASE PRESENTATION

This study presents a series of three brainstem NCs, detailing demographics, clinical presentations, radiological features, and operative findings. Patients aged 2-40 years exhibited varied symptoms including headaches, vomiting, cranial nerve deficits, and motor/sensory deficits. Literature review of 27 cases showed a mean age of 26.8 years, predominantly in females, with diverse cystic characteristics on MRI. Surgical intervention achieved mostly complete resection, with varying outcomes including recurrence and malignant transformation.

CLINICAL DISCUSSION

This study sheds light on the rare entity of brainstem NCs, emphasizing their diagnostic complexity. NCs, though constituting a minute fraction of CNS tumors, present a diagnostic challenge due to their diverse clinical presentations and rarity in the brainstem.

CONCLUSION

This study provides insights into brainstem NCs, emphasizing diagnostic complexity and the importance of MRI in accurate diagnosis and surgical intervention. Enhanced collaboration is needed to refine management strategies for these intriguing lesions.

Pediatric intracranial neurenteric cyst of the oculomotor nerve: a case-based review

BACKGROUND

Neurenteric cysts (NECs) of the central nervous system (CNS) are uncommon congenital entities arising from embryonal elements. Intracranial NECs in the pediatric population are rare.

METHODS

The authors describe the presentation, radiographic imaging, and pathologic findings of an 11-year-old boy with a right oculomotor nerve NEC. A literature review was performed to identify additional cases of pediatric intracranial NECs published in the English language, over the past 30 years (1990-2020). The authors discuss the presentation, investigations, management, and prognosis of this interesting entity.

RESULTS

We describe an 11-year-old boy who presented to neurosurgical attention with disconjugate gaze, anisocoria, and ptosis. Magnetic resonance imaging (MRI) demonstrated a lobulated, cystic, and peripherally enhancing mass involving the right oculomotor nerve. The patient underwent pterional craniotomy for drainage of the cyst and subtotal resection of the cyst wall. The tan-colored mass was displacing the basilar artery, compressing the cerebral peduncle, and adherent to the inferior surface of the tentorium. The lesion was within the oculomotor nerve and splitting the fibers, and the cystic contents were thick and mucinous. Histopathological examination of the specimen demonstrated a thin fibrous cyst wall with scattered inflammatory cells and lined by simple columnar epithelium containing mucin. The lining cells were immunoreactive with epithelial membrane antigen (EMA) and pan-keratin AE1/AE3. The diagnosis of a NEC was rendered. A comprehensive literature review of pediatric intracranial NECs yielded 46 additional lesions published in the literature, involving the skull base, posterior fossa, cerebral convexity, and cranial nerves. NECs present with local mass effect and less commonly, with aseptic meningitis or intracystic hemorrhage. Maximal safe GTR remains the mainstay management, although cyst drainage and marsupialization, cyst shunting, and fenestration of cystic contents into the ventricle or basal cisterns have been reported with variable success.

CONCLUSION

CNS NECs are rare congenital entities; although they occur less frequently in the intracranial components compared to the spine, their diagnosis and management should be considered for intracranial cystic lesions. Maximal safe GTR is the mainstay treatment and frequently yields favorable outcomes.

Intra-axial Neurenteric Cyst of Medulla: Case Report and Literature Review

Neurenteric cysts (NCs) are rare congenital lesions that are thought to result from the persistence of the neurenteric canal connecting primitive gut and neural tube. Despite the congenital nature, NCs can be diagnosed at any age and at a similar frequency in women and men. To our knowledge, 140 intracranial NCs, confirmed by histology, including the patient presented in this review, have been reported since 1952. Parenchymal NCs are extremely rare, and there are no publications describing the intra-axial NCs of the brainstem at the moment.

A 19-year-old female presented to the clinic with the following complaints: moderate dysphagia (two to three times per day) for and liquids and solids, dysphonia, vertigo, spontaneous nystagmus, imbalance, and numbness in the left side of the body, including the face. The magnetic resonance imaging (MRI) of the brain showed a well-defined lesion centered in the medulla. The patient underwent a small right-sided keyhole retro-sigmoid craniotomy. Just under the sulcus, a cyst containing pathological amorphous gray-yellow liquid was evacuated. Accessible parts of the capsule were resected without brain injury. Residual particles of the capsule were coagulated.

Two months after the operation, the patient presented with similar symptoms. We used the previous craniotomy during the second surgery. After the evacuation of the cyst, a silicone stent was set for connecting with the cerebellopontine cistern and preventing new synechiae formation. As surely as after the first surgery, all neurological symptoms gradually regressed. In two months after surgery, deglutition and sensations recovered, and hemiparesis and imbalance decreased. Postoperative MRI examination two months after surgery showed no evidence of cyst recurrence.

Intra-axial NCs are a rare group of congenital pathological lesions with a favorable prognosis. There are no publications of brainstem NCs with intra-axial localization to date. The treatment of choice in this group of patients is complete microsurgical excision followed by long-term observation.