Cerebral Echinococcosis in Children: Diagnostic Challenges and Treatment Strategies

Abstract

Aim

Hydatid cyst is an endemic zoonotic disease caused by the larval stage of Echinococcus species, with transmission occurring through parasite eggs from domestic or wild animals. Although hepatic involvement is most common in children, intracerebral localization is rare and may pose serious diagnostic and therapeutic challenges. This study aimed to evaluate the clinical presentation, diagnostic workup, treatment strategies, and outcomes of pediatric patients with intracerebral hydatid cysts.

Methods

We retrospectively analyzed 13 pediatric patients diagnosed with intracerebral hydatid cysts and followed in our tertiary care center between 2012 and 2025. Demographic, clinical, laboratory, radiological, treatment, and follow-up data were reviewed.

Results

The mean age was 8 years, with a male-to-female ratio of 1.1. Headache was the most common presenting symptom (69.2%). Six patients (46.2%) had concomitant involvement of other organs, most frequently the liver. Serological positivity was detected only in patients with hepatic involvement; all isolated cerebral cases were seronegative. All patients underwent surgical treatment. Albendazole was administered in all cases, and praziquantel was added in two resistant cases. Recurrence occurred in one patient. No mortality was observed.

Conclusion

Cerebral echinococcosis should be considered in the differential diagnosis of pediatric patients with unexplained intracranial mass lesions, particularly in endemic areas. Seronegativity does not exclude diagnosis in isolated cerebral disease. Comprehensive imaging and surgical excision remain the cornerstone of management, supported by antiparasitic therapy in select cases.

Keywords

hydatid cyst - intracerebral echinococcosis - pediatric neurosurgery - seronegativity - parasitic CNS infection - cerebral echinococcosis - albendazole

Introduction

Hydatid disease is a parasitic infection caused by Echinococcus granulosus or Echinococcus multilocularis, transmitted to humans via the fecal–oral route. The life cycle is complex, involving definitive hosts (dogs and other canids) and intermediate hosts (sheep, goats, cattle, and humans). Humans become infected primarily through contact with infected dogs or consumption of contaminated food and water.[1] The disease manifests in various clinical forms depending on the location and size of the cysts. In children, the liver is the most frequently affected organ, followed by the lungs, spleen, kidneys, and more rarely, the central nervous system.[2] Intracerebral hydatid cysts are uncommon and typically grow slowly, often remaining asymptomatic until they reach a critical size (e.g., >5 cm), exerting mass effect on adjacent brain structures. Clinical symptoms vary depending on cyst location and size, but most commonly include headache, vomiting, signs of increased intracranial pressure, and occasionally, seizures or cranial nerve palsies.[3]

Cerebral hydatid cysts may occur as solitary or multiple lesions, and are categorized as either primary or secondary. Primary cysts arise from direct hematogenous spread and are generally solitary, whereas secondary cysts may result from rupture of primary lesions and tend to be multiple. Due to their rarity and nonspecific presentation, cerebral hydatid cysts present a diagnostic challenge, particularly in non-endemic regions. Neuroimaging plays a key role in diagnosis, while serological tests may support the clinical suspicion. Surgical excision without rupture is the mainstay of treatment, often accompanied by antiparasitic therapy to reduce recurrence risk.[4]

In this study, we present a 13-year experience from a single tertiary center in an endemic region of Turkiye, focusing on the clinical characteristics, diagnostic challenges, treatment approaches, and outcomes of pediatric patients with intracerebral hydatid cysts.

Methods

Study Design and Participants

This retrospective cohort study included 13 pediatric patients diagnosed with intracerebral hydatid cysts between January 2012 and January 2025 at the Pediatric Infectious Diseases Clinic of Cukurova University Faculty of Medicine. Ethics approval for the study was obtained from the Clinical Research Ethics Committee of Cukurova University (Decision no.: 110).

Data Collection

Demographic data (age, gender, hometown), clinical features (presenting complaints, additional organ involvement), laboratory findings (eosinophil count, indirect hemagglutination test [IHA]), radiological features (cyst location and number), histopathological results, treatment modalities (medical and surgical), complications, and long-term outcomes were retrospectively reviewed from patient records and hospital database.

A positive IHA test was defined as a titer of ≥1/160. Eosinophilia was defined as an eosinophil count >450/μL or a percentage >4%. Diagnosis of cerebral echinococcosis was based on clinical, radiological, serological, and histopathological findings. All patients were evaluated for immune status, and anti-HIV tests were negative in all cases.

Surgical excision was performed on all patients, primarily utilizing the modified Dowling technique to ensure in toto cyst removal. All patients received postoperative anti-helminthic therapy with albendazole (15 mg/kg/day, divided into two doses). Postoperative follow-up involved both clinical evaluation and regular cranial imaging (MRI or CT). This follow-up was typically conducted at 3-month intervals during the first postoperative year, 6-month intervals during the second year, and annually thereafter. Patients presenting with multiorgan involvement were simultaneously monitored by the relevant pediatric subspecialty clinics following a parallel and similarly frequent schedule.

Statistical Analysis

Statistical analysis was conducted using IBM SPSS Statistics Version 20. Given the small sample size and the study's descriptive nature, only descriptive statistics were used to summarize the data. Categorical variables were expressed as frequencies and percentages, and continuous variables were expressed as means ± standard deviation.

Results

A total of 13 pediatric patients diagnosed with intracerebral hydatid cysts were included in the study. The mean age at presentation was 8 years (range: 2.5–14 years), and the male-to-female ratio was 1.1 (seven males, six females). Three patients were refugees from Syria, while the remaining cases were referred from Adana and surrounding provinces ([Table 1]). Headache was the most common presenting symptom, reported in nine patients (69.2%), followed by nausea and vomiting (53.8%). Two patients were asymptomatic and diagnosed incidentally during cranial imaging after trauma. One patient presented with visual disturbances only, while another had generalized convulsions at admission ([Table 2]).

Table 1 Clinical features and prognosis of the cases

	Age-year /City	Application date	G	Complaint	Additional organ	Cyst Hyd. IHA	Eosinophil count (%, n)	Radiological findings (location/size)	Surgical treatment/ Count	Medical treatment and duration	Survival/ Sequelae	Pathology	Follow-up
1	51/2 Şırnak	2018	M	Incidentally	(-)	(-)	%6.9/800	RP/50 mm	1	Alb. 9 m	Cured	CwE	7 years
2	21/2 Gaziantep	2018[a]	M	Incidentally	(-)	(-)	%10.7/1200	IV multiple cysts	3	Alb. + Pr. 12 m	Hydrocephalus	CwE	7 years
3	12 Adana	2012[a]	M	Headache, N&V, vision problem	Liver	1/1280	%3.4/190	RP/30 mm, BF/TO multiple	1	Alb. 12 m	Epilepsy	CwE	13 years
4	131/2 Şanlıurfa	2016	M	Headache, N&V	(-)	(-)	%5.1/380	LFP/73 mm	5	Alb. 13 m	Unfollow	CwE	Unfollow
5	11 Adana	2012	F	Headache, N&V	Liver, Sp, H, right K	1/2560	%9.7/1160	LOP/90 mm	2	Alb. 18 m	MR, Relapse after 4 years (cerebral)	CwE	Unfollow
6	71/2 Suriye	2016	M	Headache, N&V	Liver, lung	1/2560	%1.3/90	ROP/65 mm	1	Alb. 12 m	Epilepsy	CwE	Unfollow
7	6 Şanlıurfa	2015	F	Headache	(-)	(-)	%5.6/550	LFT/ size?	1	Alb. 9 m	Hydrocephalus	CwE	10 years
8	81/2 Şanlıurfa	2019	F	Headache, N&V	Liver	1/2560	%12/600	RIV/30 mm	2	Alb. + Pr. 13 m	Hydrocephalus	CwE	6 years
9	4 Suriye	2020	F	Headache, N&V	Liver	1/160	%3.3/200	LP/85 mm	1	Alb. 12 m	Cured	CwE	5 years
10	10 Niğde	2020	F	Vision problem	(-)	(-)	%1/100	LF/52 mm	1	Alb. 12 m	Cured	CwE	5 years
11	14 Suriye	2018	M	Headache, N&V	(-)	(-)	%2.3/120	LFT/10 mm	1	Alb. 2 years	Cured	CwE	7 years
12	33/4 Adana	2020	M	Convulsion	(-)	(-)	%2.7/170	LOP/25 mm	1—rupture	Alb. 12 m	Cured	CwE	5 years
13	7 Adana	2021	F	Headache	Liver, lung, Sp, K	1/2560	%13/2800	LFT/48 mm	1	Alb. 12 m	Continuing	CwE	4 years

Abbreviations: Alb, albendazole; B, bilateral; CwE, compatible with echinococcosis; F, female; F, frontal; FP, frontoparietal; FT, frontotemporal; G, gender; H, heart; IV, intraventricular; K, kidney; L, left; M, male; MR, mental retardation; N&V, nausea and vomiting; OP, occipitoparietal; P, parietal; Pr, praziquantel; R, right; Sp, spleen; TO, temporooccipital; y, years.

^a Secondary cyst hydatid.

Table 2 Application complaints and location of the cases

Complaints of application to the hospital	Patient number (%)
Headache	9 (69.2)
Nausea and vomiting	7 (53.8)
Vision problem	2 (15.3)
Incidentally	2 (15.3)
Convulsion	1 (7.6)
Additional organ involvement
Liver	6 (46.1)
Lung	2 (15.3)
Kidney	2 (15.3)
Spleen	2 (15.3)
Heart	1 (7.6)

Seven patients (53.8%) had isolated cerebral involvement. The remaining six patients (46.2%) had additional organ involvement, most frequently the liver (n = 6), followed by lungs (n = 2), kidneys (n = 2), spleen (n = 2), and heart (n = 1). In two cases, more than two extra-cerebral organ involvements were noted. Serological testing (IHA) was positive in six patients (46.1%), all of whom had hepatic involvement. In contrast, all seven patients with isolated cerebral hydatid cysts had negative serology. Eosinophilia was observed in seven patients (53.8%). Notably, four of the seven patients with isolated cerebral cysts (seronegative) also had eosinophilia ([Table 1]).

Radiologically, solitary cysts were observed in 11 patients ([Fig. 1] and [2]), while two patients had multiple intracerebral cysts ([Fig. 3]). All cysts were located supratentorially, most commonly in the temporo-parieto-occipital region. Two patients had ventricular involvement. None of the cysts showed calcification. All patients underwent surgical intervention. Four required more than one surgery. Albendazole (15 mg/kg/day) was administered in all cases. Two patients were switched to high-dose albendazole and received adjunctive praziquantel therapy due to inadequate response. No anaphylaxis was reported. One patient (Case 2) experienced intraoperative rupture and developed hydrocephalus, requiring shunt placement. Epilepsy was documented in two cases and was well controlled with antiepileptic medication. One patient had a relapse 4 years after completing treatment. All patients were alive at last follow-up.

Fig. 1 Cranial MR image of intracerebral hydatid cyst (Case 1).

Fig. 2 Hydatid cyst material removed after surgery (Case 1).

Fig. 3 Preoperative cranial MR images of Case 2 (A) and multiple cysts after rupture (B).

Discussion

Cerebral echinococcosis is an uncommon but potentially life-threatening manifestation of hydatid disease, particularly in pediatric populations.[4] [5] Although hepatic and pulmonary involvement are more prevalent, cerebral localization poses significant diagnostic and therapeutic challenges due to its rarity and nonspecific clinical presentation.[6] In our 13-year experience, most patients presented with symptoms of increased intracranial pressure, consistent with previous reports,[7] [8] though incidental diagnoses were also noted. The observed male predominance and mean age of 8 years are consistent with prior pediatric series from endemic regions.[9] [10] Interestingly, 46.2% of our cases exhibited multiorgan involvement, reinforcing the importance of thorough systemic evaluation in suspected cases. In particular, liver was the most frequently affected additional organ, which aligns with previous data showing hepatic involvement in up to 75% of hydatid cases.[11]

A noteworthy finding in our study was the poor sensitivity of serologic tests in isolated cerebral hydatid disease. IHA was negative in all cases without hepatic involvement, echoing prior studies suggesting seronegativity in up to 50% of cerebral cases.[12] [13] [14] A literature review indicates that the sensitivity of different serological tests (e.g., ELISA, IHA) for cerebral echinococcosis generally ranges from 50 to 75%, and is significantly lower than for hepatic disease.[4] [11] These results emphasize the need for clinicians to rely on imaging and clinical context when serologic tests are inconclusive. Radiological findings in our cohort were also notable: all cysts were supratentorial, and two cases involved the ventricular system.[15] [16] Such intraventricular localizations are rare and may complicate surgical planning.[17] No calcified lesions were observed, consistent with the low rate of cerebral cyst calcification reported in the literature (<1%).[18]

Surgical excision remains the cornerstone of treatment, with the goal of removing the intact cyst to prevent recurrence or anaphylaxis.[19] [20] The modified Dowling technique, involving gentle irrigation and cyst delivery, was the preferred method for intact removal.[21] In our cohort, all patients underwent surgery, and recurrence occurred in only one case over a 4-year follow-up. Case 12 experienced the intraoperative rupture, which was the patient with a solitary cyst and intraventricular involvement. This patient did not develop recurrence. The patient who developed recurrence (Case 5) had multiorgan involvement and a large cyst (90 mm). Four patients required multiple surgeries (Case 2: 3; Cases 5, 8, and 10: 2 procedures). These multiple procedures were generally necessitated by large cyst size (>5 cm), complicated locations (intraventricular or multiloculated), or early recurrence following initial surgery. For intraventricular cysts (Cases 2 and 8), open microsurgical excision was utilized. Albendazole was administered postoperatively in all cases, and in two patients with poor initial response, adjunctive praziquantel led to clinical improvement.[11] [22] Recent data support the use of combination therapy in select patients,[23] [24] despite availability constraints in some countries. Despite the complexity of surgical intervention, the neurological prognosis was favorable in most cases. Epileptic symptoms were well controlled, and hydrocephalus was successfully managed when present. The absence of anaphylactic reactions, even in one intraoperative rupture, is reassuring, though such events remain a known risk.

Our study is limited by its retrospective nature and relatively small sample size, although the rarity of pediatric cerebral echinococcosis makes larger cohorts challenging. Nevertheless, the strength of our study lies in its long-term follow-up and comprehensive clinical documentation.

Conclusion

Cerebral echinococcosis, although rare, should be considered in the differential diagnosis of pediatric patients presenting with intracranial mass lesions, especially in endemic regions. The possibility of seronegative results in isolated cerebral involvement highlights the importance of radiological imaging and clinical judgment for timely diagnosis. Our findings underscore the need for a multidisciplinary approach, including neurosurgical intervention and antiparasitic therapy, to achieve favorable outcomes. Early recognition, complete cyst excision, and appropriate follow-up remain the pillars of effective management. Screening for multiorgan involvement is also crucial to guide therapy and reduce long-term complications.

Conflict of Interest

None declared.

Acknowledgment

Special thanks to Prof. Dr. Tahsin Erman, who has shared his knowledge and experience in the intracerebral cyst hydatid infections from the perspective of neurosurgery.

Ethical Approval Statement

Ethics committee approval was received for the study at the meeting of Cukurova University Hospital Clinical Research Ethics Committee dated April 2, 2021 (Decision no.: 110).

Authors' Contribution

M.K.Ç., Ö.Ö.G., and D.A. contributed to study conception and design; M.K.Ç. and Ü.Ç. contributed to data collection; Ö.Ö.G. and D.A. contributed to analysis and interpretation of results; M.K.Ç., Ü.Ç., and Ö.Ö.G. contributed to draft manuscript preparation. All authors reviewed the results and approved the final version of the manuscript.

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Publication History

Article published online:
28 January 2026