Neuroendoscopic management of a third ventricle hydatid cyst presenting with obstructive hydrocephalus in a 4-year-old female: a case report and review of the literature

Abstract

Background

Hydatidosis is a parasitic disease caused by the larvae of Echinococcus granulosus, typically acquired through ingestion of contaminated food. While hydatid cysts commonly develop in the liver and the lungs, the central nervous system is rarely affected, and the cyst predominantly develops within the cerebral parenchyma. However, the ventricular system involvement remains extremely rare. Among the cases of intraventricular hydatid cysts, the lateral ventricles are the mostly affected, while the involvement of the third ventricle remains exceedingly rare, with only five cases previously reported in the literature.

Case Presentation

A 4-year-old Syrian female presented to the neurology department with acute right-eye strabismus, headache, and vomiting for 2 weeks. Ophthalmic examination identified papilledema involving the right eye, while radiological imaging identified a spherical cystic mass in the third ventricle, at the foramen of Monro, leading to right lateral ventricle hydrocephalus. Therefore, the strabismus was likely due to 6th cranial nerve palsy, caused by the increased intracranial pressure. The patient underwent neuroendoscopic cyst excision via the transventicular transforaminal approach. Histopathological examination corroborated the diagnosis of a hydatid cyst. Postoperative management included prolonged albendazole therapy, and follow-up imaging showed no recurrence (refer to Graphical Abstract).

Conclusion

Hydatid cysts should be considered in the differential diagnosis of intraventricular cystic lesions, although extremely rare. Further studies are necessary to guide standardized protocols for these unusual neurological entities. The surgical intervention is precision-demanding and relies on the neurosurgeon’s expertise to prevent intraoperative complications. Histopathological confirmation remains essential for diagnosis in cases of cerebral hydatid cysts.

Graphical abstract

Background

Hydatidosis is a common parasitic disease in many endemic areas such as the Middle East, Eastern Europe, and South America. It is caused by the larvae of Echinococcus granulosus, which leads to the formation of a hydatid cyst (HC) that may affect any organ in the body. The liver represents the most commonly affected organ (50–70% of cases), followed by the lung (15% of cases), while the central nervous system (CNS) is rarely affected (2–4% of cases). When the CNS is involved, the cyst predominantly develops within the cerebral parenchyma, and very rarely in the ventricular system. Although less than 50 cases of intraventricular HCs have been reported in the literature, the lateral ventricle represents the most commonly reported location in the majority of cases, while the involvement of the third ventricle remains an extremely rare presentation, with only five cases previously reported in the literature prior to our presented case [1–4]. The clinical presentation of intraventricular HCs encompasses vomiting, headaches, intracranial hypertension and seizures, corresponding to the cyst’s size and location [3]. Generally, cerebral HCs are treated surgically. However, the surgical procedure remains challenging and precision-demanding in cases of intraventricular HCs, as it carries significant risks owing to the deep location of the cyst and the potential injury to the adjacent structures [5]. In this article, we present a detailed case of a HC in the third ventricle in a 4-year-old female who presented with strabismus and signs of intracranial hypertension, along with a concise review of the previously reported cases in literature.

Case presentation

A 4-year-old Syrian female presented to the Neurology Department with acute-onset ocular strabismus (esotropia) in the right eye, headache, and vomiting of 2 weeks’ duration (Fig. 1A).

Fig. 1.

Preoperative image A showing strabismus (esotropia) in the right eye while the left eye was normal. Postoperative image B exhibited complete resolution of the strabismus

The patient had no prior medical history, and there is no family history of neurological, ophthalmological, or genetic disorders. The patient lives in an urban environment and has no rural residency background or direct contact with animals. During initial neurological examination, the patient was fully conscious with a Glasgow Coma Scale (GCS) score of 15/15. She had a unilateral esotropia affecting the right eye, while the rest of the cranial nerves were normal. The motor examination revealed normal tone and power (5/5) in all extremities. Deep tendon reflexes were symmetric and within normal limits, and plantar responses were flexor bilaterally. Sensory examination was intact for all modalities, and coordination tests were normal. Gait was steady without abnormalities. No signs of meningeal irritation were present. The ophthalmic examination via fundoscopy revealed unilateral papilledema involving the right eye, while the left eye was normal. No other clinical manifestations were noted. Blood tests were all within normal limits except for leukocytosis, with a white blood cell count of 14.5 × 10⁹/L and mild eosinophilia 8% (0.8 × 10⁹/L) compared with the normal range of 1–6% (0.1–0.5 × 10⁹/L). Contrast-enhanced magnetic resonance imaging (MRI) identified a nonenhancing, fluid-filled cystic lesion, measuring approximately 3 × 2 × 2 cm, located in the third ventricle at the foramen of Monro of the right lateral ventricle, associated with ventricular enlargement and hydrocephalus, leading to intracranial hypertension and leftward displacement of the septum pellucidum (Fig. 2).

Fig. 2.

Contrast enhanced magnetic resonance imaging of the brain with sagittal view (A), coronal view (B) and axial view (C) showing a nonenhancing, fluid-filled cystic lesion, measuring approximately 3 × 2 × 2 cm, located in the third ventricle at the foramen of Monro (red arrows), leading to right lateral ventricle hydrocephalus (blue arrow). The cyst exhibits hyperintensity on T2-weighted images (A) and hypointensity on T1-weighted images (B and C)

Consequently, the observed strabismus in our case was likely due to a unilateral 6th cranial nerve palsy secondary to raised intracranial pressure from the hydrocephalus. Subsequently, enzyme-linked immunosorbent assay (ELISA) yielded a positive result for IgG antibodies against Echinococcus granulosus, with an index value of 2.8 (cut-off ≥ 1.1, according to the manufacturer’s instructions), therefore, the preoperative diagnosis of HC of the third ventricle was proposed, despite being extremely rare in this location. The surgical intervention was indicated, and the patient was subsequently referred to the Neurosurgery Department for the appropriate management. Considering the deep-seated location of the HC, the presence of hydrocephalus and to minimize morbidity rates associated with more invasive approaches, neuroendoscopic excision utilizing the transventicular transforaminal approach was performed following appropriate preoperative preparation, entering via the anterior horn of the dilated right lateral ventricle, during which the cerebrospinal fluid (CSF) emerged under high pressure. The cyst was visualized at the foramen of Monro, and aspiration of the cyst’s contents yielded clear, nonviscous fluid. After aspiration, the complete excision of the cyst capsule from the third ventricle was achieved without intraoperative rupture, leakage, bleeding or structural injury, despite the minimal adhesion to the ventricular wall. Repeated irrigation with saline was performed to confirm full resection, and no ventricular drain was placed (Fig. 3).

Fig. 3.

Intraoperative view showing neuroendoscopic excision of the cyst. The cyst puncturing (A), the aspiration of the cyst’s contents (B) and the resection of the cyst (C). Postoperative image revealing the complete resection of the intraventricular hydatid cyst (D)

The total resected cyst and the aspirated fluid were subjected to histopathological examination, which confirmed the diagnosis of intraventricular HC (Fig. 4).

Fig. 4.

Microscopic examination with hematoxylin and eosin staining shows cystic wall composed of acellular laminated capsule with inner cell monolayer (germinal membrane), budding protoscolices (round to ovoid bodies, with irregular eosinophilic central cavity and hooklets), consistent with the diagnosis of hydatid cyst. Cytological examination of the fluid reveals acellular smears, on clean background. No evidence of any atypical or malignant features within received specimen

Postoperatively, symptoms of intracranial hypertension resolved, with complete disappearance of the ocular strabismus within 1 week (Fig. 1B). Further systemic evaluation revealed unremarkable findings, and the appropriate albendazole therapy was initiated for 6 months to minimize the risk of recurrence. Follow-up with computed tomography (CT) imaging of the brain after 6 weeks of surgery showed full resolution of hydrocephalus and complete cyst removal with no recurrence (Fig. 5).

Fig. 5.

Follow-up CT after 6 weeks following the surgical intervention revealed complete resolution of hydrocephalus with no signs of recurrence

Ongoing clinical and radiological surveillance is planned to monitor for recurrence or further dissemination.

Discussion

Hydatid disease, also known as echinococcosis, is a parasitic disease caused by the larval stage of the tapeworm Echinococcus granulosus. It spreads from animals like dogs and sheep to humans, and leads to the formation of HC, which may potentially affect any organ in the human body. The liver and lungs are the most frequently involved sites for HC, accounting for the majority of cases. However, the infection may also occur in the brain, spleen, kidneys, and heart, though the involvement of these sites is less common [1, 6]. Cerebral HCs account for roughly 2–4% of all echinococcal infections and are almost exclusively supratentorial, typically located within the cerebral hemispheres, with a pronounced predilection for regions supplied by the middle cerebral artery [3, 4]. Additionally, cerebral HCs are often noted in pediatric patients, accounting for over 70% of all cases of intracranial HCs [3]. HCs within the cerebral ventricles are exceptionally uncommon, with less than 50 cases documented in the literature. Furthermore, the involvement of the third ventricle is exceedingly rare, with only five cases previously reported in literature to date [4]. Although the exact etiology behind intraventricular HCs remains unclear, Habibi et al. outlined three possible etiologies for intraventricular cyst formation [5]:

1. Spontaneous rupture of the ependyma facilitating cyst emergence within the ventricular system.

2. Direct entry into the ventricles through the choroid plexus.

3. Leakage of contents from a primary HC adjacent to the ependymal layer into the ventricles.

In general, the clinical presentation of HCs varies depending on the cyst’s anatomical location and size, while some cysts remain asymptomatic [6]. However, cerebral and ocular hydatid cysts typically manifest earlier than other forms of infection due to their sensitive anatomical locations [7]. The most documented clinical manifestations of intraventricular hydatid cysts include signs of elevated intracranial pressure, such as nausea, vomiting and headache, accompanied by papilledema, localized neurological deficits and seizure episodes, though these features are nonspecific and may be encountered in a variety of other conditions [4]. Our 4-year-old patient had ocular strabismus in the right eye, which was an expected consequence of 6th cranial nerve palsy, resulting from the intracranial hypertension. Sixth cranial nerve palsy is the second most commonly affected cranial nerve in children, with an incidence of 2.5 cases per 100,000. Intracranial hypertension, neoplastic disorders and vascular abnormalities remain the most important risk factors for this condition in pediatric patients. It manifests as horizontal diplopia resulting from weakness of the lateral rectus muscle on the affected side. Although the symptoms of sixth cranial nerve palsy are related to the specific cranial nerve itself, false localizing sign may be noted in a patient with intracranial hypertention, which results in stretching of the sixth nerve as it passes over the base of the skull [8]. The false localizing sign observed in our patient is noteworthy in the context of third ventricle HC, expanding the clinical picture of such rare entities. Consequently, owing to the rarity of intraventricular HCs and the nonspecific clinical presentation, they are susceptible to misdiagnosis, prompting further investigations to provide accurate correlation [4]. Although the considerations for cystic lesions located in the third ventricle include a variety of differentials, such as arachnoid cysts, colloid cysts and ependymal cysts, the radiological imaging utilizing CT and MRI enables the characterization of hydatid cysts while excluding other differential diagnoses [3, 4]. MRI depicts hydatid cysts as well‐demarcated, thin‐walled lesions with hypointense contents on T1-weighted images and hyperintense contents on T2-weighted images, the fibrous capsule may appear as a distinct low-signal rim on both sequences, while CT demonstrates Hydatid cysts as thin-walled, sharply marginated spherical or ovoid masses with homogeneous density, absent pericystic edema, and without contrast enhancement [4]. Contrast enhanced MRI of the brain in our patient identified a spherical nonenhancing, fluid-filled cyst, measuring approximately 3 × 2 × 2 cm, located in the third ventricle at the foramen of Monro of the right lateral ventricle, along with right ventricular enlargement. The cyst exhibited hyperintensity on T2-weighted images and hypointensity on T1-weighted images, proposing the preoperative diagnosis of HC. In general, the diagnosis of hydatid disease typically relies on serological tests with high sensitivity and specificity, including latex agglutination, ELISA, immunoblotting, and indirect hemagglutination. However, postoperative histopathological examination remains the gold standard for definitive confirmation, particularly in cases of secluded cerebral HCs, since the serological tests may exhibit limited specificity and sensitivity [3, 4, 6]. ELISA test of IgG antibodies against Echinococcus granulosus yielded positive results in our patient, supporting the preoperative diagnosis of HC of the third ventricle. Traditionally, cerebral HCs are managed through surgical intervention. The primary objective is to extract the intact cyst along with its contents, thereby preventing the spillage of hydatid fluid, which could precipitate an acute anaphylactic reaction. While the intact removal of cerebral HCs utilizing the Dowling’s technique remains the recommended option, deep-seated or intraventricular HCs present significant challenges owing to the difficulty in delineating a safe surgical route and the increased risk of intraoperative rupture of the HC. Consequently, some neurosurgeons advocate performing a corticotomy equal to the diameter of the cyst, though it may carry higher morbidity, while some others recommend initial intracystic aspiration followed by complete excision of the cyst wall for deeply located cysts, though it may be associated with a potentially greater recurrence risk [5]. In pediatric patients with third ventricular lesions, the endoscopic transventricular transforaminal approach provides a safe intervention for restoration of CSF flow, lesion removal and conducting biopsies, though the surgical outcomes depend both on surgeon expertise and selecting the right indications. Rigorous preoperative planning and the comprehensive assessment of the advantages and limitations of each approach are essential for a precise procedure [9]. Our patient underwent neuroendoscopic excision of the HC utilizing the transventicular transforaminal approach without intraoperative complications, and the total resected specimen was subjected to histopathological examination. HCs under microscopic examination exhibit hallmark features, such as a noncellular laminated wall and an inner germinal membrane composed of cellular elements, along with the presence of protoscolices or brood capsules within the cyst cavity [7]. Postoperative histopathological examination confirmed the diagnosis of HC in our case. Considering that additional lesions may be present in other organs beyond the primary site of HC in approximately 20% of hydatid disease patients, a comprehensive postoperative radiological assessment such as abdominal and pelvic ultrasound and chest X-ray is essential following surgery [3]. Further systemic evaluation of our patient yielded unremarkable findings, and the appropriate management with albendazole was initiated to minimize the risk of recurrence. Albendazole therapy plays a dual role in the management of hydatid disease. When administered preoperatively, it reduces cyst viability, facilitating surgical intervention. While postoperative administration decreases the risk of disease recurrence [6]. The follow-up with brain CT showed full resolution of the intraventricular HC with no recurrence, and the patient is undergoing clinical and radiological surveillance to detect any recurrence or further dissemination. A concise literature review of all cases of third ventricle hydatid cyst is provided at (Table 1). Our patient’s presentation with strabismus contrasts with the seizures reported by Habibi et al. and the altered sensorium in the case by Qadri et al., highlighting the variable clinical manifestations dictated by cyst location and degree of CSF obstruction, and the surgical intervention in our case was performed utilizing the transventricular transforaminal neuroendoscopic approach, which was ideal for our specific case, particularly owing to the HC’s deep-seated location near the foramen of Monro, the presence of hydrocephalus; facilitating ventricular entry, while considering the minimally invasive nature of the approach, especially in pediatric patients.

Table 1.

Literature review of all cases of hydatid cyst in the third ventricle

Author (year)	Age and sex	Symptoms	Key radiological findings	Management	Outcome
Prasad et al. (2013) [10]	20-year-old male	Diminution of vision and headache	Third ventricle solitary cyst with hydrocephalus	Endoscopic excision	Improvement
Habibi et al. (2013) [5]	16-year-old female	Seizures and progressive deterioration in consciousness	Large spherical cyst within the third ventricle with slight extension to the left	Dowling’s technique	Improvement
Samadian et al. (2020) [3]	3-year-old female	Drowsiness, nausea, vomiting and headache	Large spherical cyst within the third ventricle with enlargement in the lateral and third ventricles	Dowling’s technique	Improvement
Maamri et al. (2022) [4]	7-year-old female	Signs of intracranial hypertension, deterioration in general status and weakness on the right side	Spherical cyst within the third ventricle and dilation of the ventricular system	Excision through transfrontal transventicular approach	Improvement
Qadri et al. (2022) [2]	24-year-old male	Tinnitus, decreased hearing, headache, vertigo, fever, altered sensorium, nausea and vomiting	Intraventricular cystic tumor with speckled calcifications and intraventricular hemorrhage, as well as hydrocephalus	Excision through parieto-occipital craniotomy with transcortical transventicular approach	Improvement
Our case	4-year-old female	Acute-onset ocular strabismus (esotropia) in the right eye, headache, and vomiting of two weeks’ duration	Intraventricular cystic lesion located in the third ventricle at the foramen of Monro, leading to right lateral ventricle hydrocephalus	Neuroendoscopic excision through transventicular transforaminal approach	Improvement

Conclusion

This case underscores the importance of considering HCs in the differential diagnosis of intraventricular cystic lesions, although extremely rare. Considering the challenges in the management of deep-seated HCs, our case further emphasize the need for more research to establish adequate guidelines for the surgical management of intraventricular HCs. The surgical intervention majorly relies on the neurosurgeon’s expertise, therefore a high index of vigilance and precision is required to avoid any intraoperative complications. Histopathological examination remains the confirmative investigation in cases of cerebral HCs. A prolonged post-operative albendazole therapy should be considered to minimize the risk of recurrence.

Methods: This article is reported in line with the CARE criteria for case reports [11].

Abbreviations

HC

Hydatid cyst

CNS

Central nervous system

GCS

Glasgow Coma Scale

MRI

Magnetic resonance imaging

ELISA

Enzyme-linked immunosorbent assay

CSF

Cerebrospinal fluid

CT

Computed tomography

Author contributions

Ahed Assaf, Suleiman Khaddour, Saja Karaja, Mousa Barboura, William Borghol, and Hamed Alfakhouri carried out data curation, writing—review and editing, and writing—original draft. Jalal Alnajjar carried out writing—review and editing and performed the surgical procedure. Ahmad Zahi AlChawwaf carried out writing—review and editing and supervision. All authors approved the final manuscript. Ahed Assaf revised and submitted the manuscript.

Funding

This research did not receive any funding.

Data availability

Not applicable.

Declarations

Ethics approval and consent to participate

This study was reported by the Faculty of Medicine, Hama University, Hama, Syria. Our mentioned institution waives ethics approval for reporting individual cases. The patient’s father gave consent to participate in this study.

Consent for publication

Written informed consent was obtained from the patient’s father for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

The authors declare no competing interests.