Pediatric cerebral sparganosis mimicking low-grade glioma in a nonendemic region: illustrative case

Abstract

BACKGROUND

Cerebral sparganosis is a rare parasitic infection of the CNS caused by the Spirometra species. Pediatric intracranial involvement is exceptionally uncommon and has been reported predominantly from endemic regions in Asia. Preoperative diagnosis is challenging because clinical and radiological features frequently mimic neoplastic lesions.

OBSERVATIONS

An 11-year-old girl presented with new-onset seizures. MRI demonstrated a small, peripherally enhancing lesion in the right parietal lobe with surrounding vasogenic edema and intralesional calcifications, initially interpreted as a pediatric low-grade glioma. The patient underwent supramarginal resection. Histopathological examination revealed inflammatory changes with parasitic structures consistent with Spirometra species. A structured review of the literature identified 77 pediatric cases, showing a modest male predominance, a mean age of 11.01 years, seizures as the most common presenting symptom, a frontal-parietal predominance of lesions, frequent preoperative misdiagnosis, and inconsistent peripheral eosinophilia.

LESSONS

Pediatric cerebral sparganosis can closely mimic low-grade glioma on neuroimaging, especially in nonendemic regions. Absence of peripheral eosinophilia or a clear exposure history does not exclude the diagnosis. Awareness of this entity is critical to avoid misdiagnosis, and complete excision remains the most effective diagnostic and therapeutic strategy in tumor-like presentations.

https://thejns.org/doi/10.3171/CASE264

Sparganosis is a rare but severe parasitic infection caused by infestation with the sparganum larva of Spirometra species.¹ Although cases have been reported worldwide, the disease shows a markedly higher prevalence in East Asian countries, including China, South Korea, Japan, and Thailand.² Cerebral sparganosis primarily affects young to middle-aged adults, with most large series reporting mean or median ages in the mid-30s.^3,4 Humans acquire the infection through ingestion of raw or undercooked snakes, frogs, or freshwater fish harboring spargana; consumption of untreated water containing procercoid infected copepods; or application of raw flesh from intermediate hosts as part of traditional poultice practices.⁵

Clinical manifestations of cerebral sparganosis include headache, seizures, hemiparesis, and various focal neurological deficits. Preoperative diagnosis is often challenging, and historically many cases were diagnosed only after surgical removal of the parasite and confirmatory histopathological examination. With advancements in serological assays and neuroimaging techniques, however, preoperative diagnosis has become increasingly feasible.⁶ Cerebral sparganosis is characterized by extensive, multifocal, or migratory T2-hyperintense lesions with surrounding vasogenic edema, and contrast-enhanced MRI typically demonstrates ring-like, beaded, or serpiginous tubular enhancement.^7–9 Excision is the optimal treatment for cerebral sparganosis, whereas high-dose praziquantel and, in selected cases, adjunctive albendazole may be considered for surgically inaccessible lesions.¹⁰

Given the rarity of intracranial sparganosis in the pediatric population, we present an illustrative case of cerebral sparganosis in an 11-year-old girl from a nonendemic region, in whom the lesion closely mimicked a pediatric low-grade glioma. The patient presented with new-onset seizures, and preoperative neuroimaging strongly favored a neoplastic etiology; however, definitive diagnosis of cerebral sparganosis was established by postoperative histopathological examination. To our knowledge, this represents the first reported pediatric intracranial sparganosis case occurring outside Asia. In addition, we provide a structured review of the literature to highlight the clinical characteristics, diagnostic challenges, and therapeutic considerations associated with this rare parasitic disease.

Illustrative Case

Presentation and Preoperative Evaluation

An 11-year-old girl presented with a 3-month history of intermittent headaches and three episodes of afebrile focal-onset seizures accompanied by visual aura. Her family history was notable for her mother’s prior neurosurgical intervention for a brain tumor, followed by death on the 2nd postoperative day. On admission, the patient’s general physical and neurological examinations were unremarkable, and both respiratory and abdominal examinations were within normal limits. Preoperative laboratory studies demonstrated microcytic hypochromic anemia and an elevated C-reactive protein level, suggestive of an underlying inflammatory or tumor-related process. Coagulation testing showed a prolonged international normalized ratio, attributed to vitamin K deficiency and potential medication effects. Renal and hepatic function tests were normal, and no peripheral eosinophilia was identified.

Preoperative sleep-wake EEG demonstrated paroxysmal epileptiform activity within bilateral centro-parietotemporal areas, with right-hemispheric predominance. Cranial MRI revealed a 13 × 7–mm lesion in the right superior parietal lobule with signal intensity comparable to white matter on both T1- weighted (T1W) and T2-weighted (T2W) sequences and showing predominantly peripheral enhancement following gadolinium administration (Fig. 1). T2W images demonstrated marked perilesional vasogenic edema. Susceptibility-weighted imaging identified multiple punctate intralesional calcifications. MR spectroscopy showed a choline-to-creatine ratio of 0.86 without a discrete choline peak. Based on these imaging characteristics, the initial differential diagnosis included a polymorphous low-grade neuroepithelial tumor, glioneuronal tumors, and, less likely, angiocentric glioma.

FIG. 1.

Multiparametric preoperative MR images of pediatric cerebral sparganosis initially interpreted as a low-grade glioma. A and E: T1W postcontrast coronal (A) and axial (E) images demonstrating a 13 × 7–mm, well-circumscribed lesion (arrows) with peripheral rim enhancement. B and F: T2W coronal (B) and axial (F) sequences showing prominent surrounding vasogenic edema (dashed lines). C and D:Single-voxel MR spectroscopic images obtained over the enhancing region revealing a choline-to-creatine ratio of 0.86 without a discernible choline peak. G: Susceptibility-weighted image identifying multiple punctate susceptibility foci consistent with microcalcifications (arrowheads). H: Dynamic perfusion image showing no elevated relative cerebral blood volume, with perfusion values comparable to adjacent parenchyma. Taken together, these findings supported a preoperative working diagnosis of a low-grade glioma.

Surgical Procedure

A lazy-S incision was made over the right parietal region, followed by a tailored parietal craniotomy. The dura was opened and reflected toward the superior sagittal sinus. Neuronavigation was used to localize the lesion and its margins, and a focused corticectomy was performed to access the lesion, which extended toward the atrium of the lateral ventricle. A neuronavigation-guided biopsy specimen was obtained from the contrast-enhancing component of the lesion and submitted for intraoperative consultation.

Intraoperative pathology consultation, performed by a nonneuropathologist, demonstrated astrocytic cells, and the background vasculature showed a delicate, chicken wire–like appearance. An accompanying inflammatory infiltrate, particularly in a perivascular distribution, was also noted. Under intraoperative consultation conditions, these findings raised the possibility of a glial or glioneuronal neoplasm; however, a definitive diagnosis was not rendered at that time. The lesion was then circumferentially dissected and removed in supramarginal fashion. It appeared distinctly firmer than the surrounding white matter and exhibited a dirty white-yellow coloration.

Postoperative Course and Follow-Up

Postoperative MRI demonstrated a well-defined surgical cavity in the right parietal region measuring 37 × 25 × 55 mm, with no evidence of residual lesion, confirming supramarginal resection. The patient’s neurological examination remained unchanged from baseline, and no new deficits were observed. Histopathological analysis revealed dense lymphoplasmacytic inflammation, clusters of histiocytes, scattered eosinophils, reactive gliosis, and parasitic structures embedded within the brain parenchyma (Fig. 2). Subsequent consultation with a parasitology specialist identified the organism as Spirometra species.

FIG. 2.

A:In the hematoxylin and eosin sections of the aspirate, a parasitic structure was identified in a single microscopic field within a background of gliotic brain parenchyma. B and C: The organism demonstrated an eosinophilic tegument overlying a pale myxoid stroma (B), with characteristic longitudinal bundles of smooth muscle fibers (C).

Pediatric infectious disease consultation was obtained. On examination, no palpable nodules were identified in the skin or subcutaneous tissues, and palpation of the extremity musculature revealed no painful or painless lesions. Further history revealed that the patient lived in a rural village in Georgia and regularly consumed untreated well water; there was no known ingestion of raw or undercooked frog or snake meat.

Postoperatively, the patient was started on dexamethasone (0.1 mg/kg/day) and albendazole (7.5 mg/kg/dose, twice daily) for a 2-week course, in order to address retained viable parasitic fragments and prevent recurrence. Regarding medical adjunctive therapy, albendazole was chosen over praziquantel solely because praziquantel is not commercially available in Turkey. Preoperatively, levetiracetam had been initiated at 500 mg twice daily for seizure control and was subsequently increased to 600 mg twice daily. Given the potential for concurrent parasitic infections, additional evaluations, including abdominal, thoracic, cardiac, and ophthalmological examinations, were performed, and QuantiFERON and Taenia solium IgG assays were obtained; all findings were unremarkable. At the 6-month follow-up, the patient had experienced no further seizures and remained seizure free. Interval MRI at 6 months demonstrated a CSF-filled resection cavity with expected postoperative evolution and no evidence of disease progression (Fig. 3).

FIG. 3.

A and C:Early postoperative T2W axial (A) and coronal (C) images showing expected postoperative changes with a resection cavity consistent with supramarginal resection. B and D:Six-month follow-up T2W axial (B) and coronal (D) images demonstrating a stable postoperative appearance without interval progression.

Informed Consent

The necessary informed consent was obtained in this study.

Discussion

Observations

Pediatric cerebral sparganosis is an exceptionally rare CNS infection, with the vast majority of reported cases originating from East and Southeast Asia. To contextualize the present case, we performed a structured literature review using predefined search terms across the PubMed/MEDLINE, Scopus, Cochrane Library, and Web of Science databases, with systematic extraction of demographic, clinical, imaging, treatment, and outcome data from published pediatric cases. Detailed case-level data for previously reported pediatric cerebral sparganosis cases are summarized in Table 1.^68,9,11–24 Our pooled analysis of 77 cases, together with the present 11-year-old girl, outlines several consistent epidemiological and clinical patterns while extending the known geographic distribution to include Turkey and Georgia. To our knowledge, this represents the first reported pediatric intracranial sparganosis case in Turkey and the first documented case originating from Georgia, emphasizing that sparganosis should be considered even in nonendemic regions when supportive epidemiological and imaging features are present.

TABLE 1.

Reported cases of pediatric cerebral sparganosis in the literature

Authors & Year	No. of Patients	Age, yrs/Sex (n)	Exposure (n)	Presenting Symptoms (n)	Eosinophilia (n)	Lesion Location (n)	Diagnosis Before Op (n)	Treatment (n)	Prognosis (n)
Chan et al., 198711	1	12/F	Untreated water	Hemiparesis, Sz	No	Frontal	Glioma (radiology)	Op	Disease free at 2 yrs
Anegawa et al., 198912	1	7/M	—	Hemiparesis	Yes	Thalamus migrated to frontotemporal	Low-grade astrocytoma (stereotactic biopsy)	CTx, then op	—
Moon et al., 19939	1	16/M	Raw snake	Sz, hemiparesis	—	Bilat frontal, lt parieto-occipital	—	Op	—
Kim et al., 199713	1	6/F	Untreated water	Sz	—	Parieto-occipital migrated to occipital	Lymphoma, sparganosis (radiology)	Op	Disease free at 28 mos
Bo & Xuejian, 200614	1	6/M	—	Sz, HA, nausea	No	Frontal	Inflammatory granuloma (radiology)	Op	Disease free at 6 mos
Alibhoy et al., 200715	1	13/M	—	Sz	No	Frontal	—	Op	—
Song et al., 20076	2	9/M, 14/M	Raw snake (1)	HA (2), Sz (2)	—	Basal ganglia migrated to parietal lobe (1)	—	—	—
Wang et al., 201216	1	15/F	Raw frog	Numbness, Sz	—	Frontal migrated to frontal	Tapeworm (radiology)	Op	Disease free at 26 mos
Gong et al., 20128	18	Mean 9/F (8), M (10)	Raw frog (2), untreated water (2), raw crab (2), no history (12)	Sz (9), HA (7), AMS (5), hemiparesis (4), dizziness (2), blurred vision (2), projectile vomiting (1)	—	Parietal (11), frontal (7), temporal (4), occipital (2), basal ganglia (1), cerebellum (1), pons (1)	Brain tumors (4) (radiology)	Praziquantel (14), op (4)	Remission (12), stable (5), deterioration (1)
Chu et al., 201317	7	Mean 13.14/F (2), M (5)	—	Sz (5), ophthalmoplegia (1), facial paresis (1), HA (1), dizziness (1), vomiting (1), numbness (1)	—	Frontal (7), parietal (2), 4th ventricle (2), deep white matter (1)	—	Op (7)	—
Hong et al., 201318	11	Mean 12.72/F (1), M (10)	—	Sz (8), hemiparesis (5), HA (5), paresthesia (1), weakness (1), aphasia (1)	Mean 5.29%	—	—	Op (7), stereotactic aspiration (2), praziquantel (2)	—
Li et al., 201319	2	12/M, 13/M	Untreated water (1), raw frog (1)	Sz (2)	—	Frontal migrated to thalamus (2)	—	Biopsy (1), praziquantel (2)	Initial lesion degenerated, migrated to new location
Yu et al., 201620	9	Mean 8.79/F (3), M (6)	Raw snake (2), untreated water (1), swimming in the lake (1), playing in the paddy (1), no history (4)	Sz (5), HA (4), fever (2), vomiting (1), AMS (1), blurred vision (1), numbness (1), mass lesion (1)	Yes (6), no (3)	Parietal (7), frontal (3), temporal (2), occipital (2)	—	Op + praziquantel (8)	Remission (5), poor neurological outcome (3), died (1)
He et al., 202121	6	Mean 13.17/F (2), M (4)	Untreated water (2), unknown (4)	Sz (6), HA (2), weakness (20), vomiting (1)	—	Frontal (4), temporal (2)	—	Op (6)	Sz free (4), similar frequency of Sz (1), increased frequency of Sz (1)
Feng et al., 202222	12	Mean 12.5/F (6), M (6)	Untreated water (4), raw snake (1), no history (7)	Sz (9), HA (6), vomiting (4), weakness (2), dizziness (2), hemiparesis (1), memory & psychiatric changes (1), difficulty walking (1)	Yes (1), no (11)	Occipital (2), temporal (2), corpus callosum (2), frontal (2), thalamus (1), cerebellum (1), parietal (1), basal ganglia (1), brainstem (1)	—	Op (4), op + antiparasitic (4), antiparasitic (4)	—
Chen et al., 202323	1	4/F	Raw frog	Lower limb paralysis	Yes	Rt frontoparietal lobe & splenium of corpus callosum migrated to occipital lobe	Inflammatory lesions (radiology)	10–25 mg/kg/day praziquantel, then op	Medical treatment failed, required op
Rathore et al., 202424	1	8/F	—	Fever, Sz	Yes	Parietal migrated to temporal	Cerebral tuberculosis (radiology)	Biopsy, then praziquentel at 25 mg/kg/day for 7 days	Remission, asymptomatic at 4 mos
Present case	1	11/F	Untreated water	Sz, HA	No	Parietal	Low-grade glioma (radiology & intraop consultation)	Op	Disease free at 6 mos

AMS = altered mental status; CTx = chemotherapy; HA = headache; Sz = seizure; — = not reported.

Across the pediatric cases summarized in our review, male patients predominated, with a male-to-female ratio of approximately 1.75:1. Age at presentation clustered within late childhood and early adolescence, with a mean age of 11.01 years (Table 1). The patient in our case falls within this typical age range. The most common clinical presentation was seizures, observed in 54 of 77 (70.13%) cases. Headache (29/77 [37.66%]), hemiparesis or other focal motor deficits (20/77 [25.97%]), vomiting (9/77 [11.69%]), dizziness (5/77 [6.49%]), and visual symptoms (4/77 [5.19%]) followed in decreasing order of frequency (Table 1). Our patient presented with new-onset focal seizures and intermittent headache, aligning closely with this dominant symptom pattern. The absence of fever, meningismus, or systemic signs in our case is also typical; cerebral sparganosis often lacks overt systemic inflammatory features despite being a parasitic infection.²⁵

Reconstruction of the route of infection remains challenging in the pediatric population. In contrast to mixed-age series, in which more than half of patients report an identifiable exposure, most commonly untreated water or ingestion of raw or undercooked frog or snake meat, nearly two-thirds of pediatric cases lack a recognizable risk factor¹⁸ (Table 2). This pattern highlights two important points: 1) drinking untreated water is a major but often underappreciated transmission route, and 2) absence of a classic foodborne exposure history does not exclude sparganosis, particularly in children who may not accurately recall remote exposures. Interestingly, there were no cases of transmission through poultice, which is a relatively common transmission in other types of sparganosis cases.³ In our case, the only identifiable risk factor was regular consumption of untreated well water in a rural Georgian village.

TABLE 2.

Routes of exposure in pediatric cerebral sparganosis cases

	No. (%)
Consumption of untreated water (e.g., well or spring water)	13 (16.88)
Ingestion of raw or undercooked frog or snake meat	10 (12.99)
Other risk factors	4 (5.19)
No identifiable exposure history	50 (64.94)

In the literature, there is a clear predilection for the frontal and parietal lobes in pediatric cerebral sparganosis. The frontal lobe was the most frequently affected region (32 lesions), followed by the parietal lobe (27 lesions). Less commonly, lesions involved the temporal and occipital lobes, deep gray nuclei, cerebellum, or brainstem (Table 1). Formal statistical comparison of anatomical distribution is limited by inconsistent lesion descriptions across reports, frequent documentation of migratory lesions, and the tendency of larger lesions to span multiple lobes. Nevertheless, the disproportionately high number of frontal and parietal localizations suggests a considerable predilection for these regions. Furthermore, multiple authors have emphasized that lesion migration over time is a hallmark of cerebral sparganosis, with the larva traveling along white matter tracts and producing serially changing or “wandering” lesions (Table 1). Depending on the length and direction of migration, lesions may move between lobes, and follow-up MRI can reveal evolving enhancement patterns, the classic “tunnel sign,” and microcalcifications.

Peripheral eosinophilia, although traditionally associated with parasitic infections, is not a reliable marker in cerebral sparganosis. In our pooled pediatric data, only about one-third of children with available laboratory results demonstrated eosinophilia (10/28 [35.71%] documented cases), while the majority had normal eosinophil counts (18/28 [64.29%] documented cases) despite confirmed intracranial disease. Thus, the absence of eosinophilia should not lower clinical suspicion, and relying on it as a screening tool may delay appropriate diagnosis and management.

In the literature, a considerable number of children were initially suspected of having primary brain tumors (e.g., low-grade glioma and glioneuronal tumor), demyelinating/inflammatory lesions, lymphoma, or tuberculoma, with definitive diagnosis made only after surgical removal and histopathological analysis (Table 1). Although precise quantification is limited by inconsistent reporting of preoperative impressions across publications, at least 11 cases were explicitly documented as misdiagnosed, including one in which the error was recognized only after pathological review. Notably, in the largest pediatric series to date, Gong et al. reported on 18 children with cerebral sparganosis, 4 of whom had been initially misdiagnosed, even though the study was conducted in an endemic region.⁸ This underscores the inherent difficulty of achieving an accurate preoperative radiological diagnosis, even in centers familiar with the disease.

Traditionally, the definitive diagnosis of cerebral sparganosis has relied on histopathological identification of parasitic structures within resected tissue, often supported by surrounding eosinophil-rich inflammatory infiltrates and reactive gliosis. While histopathological analysis used to be the diagnostic gold standard, it may be limited when parasitic morphology is fragmented, degraded, or not clearly visualized. In our case, intraoperative consultation was performed by a nonneuropathologist, and smear preparations demonstrated astrocytic cells within a delicate, chicken wire–like vascular background accompanied by a prominent perivascular inflammatory infiltrate. Under frozen-section conditions, these findings raised the possibility of a glial or glioneuronal neoplasm. On retrospective review by a neuropathologist, the smear slides were reevaluated and found to contain abundant reactive astrocytes accompanied by a prominent lymphocytic infiltrate, findings most consistent with a reactive/inflammatory process rather than a neoplastic lesion. This highlights the recognized limitation of intraoperative consultation in inflammatory or parasitic lesions, where reactive gliosis and vascular patterns may closely mimic low-grade glioma, particularly when parasitic structures are not readily identified.

Beyond conventional histopathological and serological assays, molecular techniques have emerged as valuable adjuncts for definitive diagnosis. Polymerase chain reaction amplification of target genes, such as mitochondrial gene regions (cox1 or nad1), can reliably confirm Spirometra species from tissue, particularly when the morphology is atypical or when differentiation between closely related subspecies, such as S. erinaceieuropaei and S. decipiens, is required.²⁶ More recently, targeted or whole-genome next-generation sequencing has enabled species-level identification from minute tissue samples, enhancing diagnostic accuracy in atypical, ambiguous, or nonendemic presentations.²⁷ These modalities are especially useful in scenarios in which preoperative misdiagnosis is likely or serological testing is inconclusive.

Resection was the predominant treatment strategy, undertaken in 51 of 77 (66.23%) pediatric cases. Among surgically managed patients, the majority achieved substantial clinical improvement or complete remission, especially when gross-total excision of the lesion and parasite was documented (Table 1). In contrast, outcomes associated with praziquantel-based therapy alone (reported in 23/77 [29.9%] patients) have been highly variable. While some studies describe symptomatic improvement, reduction in lesion size, or better seizure control following high-dose praziquantel, others report recurrence, lesion migration, or inadequate radiological response, ultimately necessitating excision. In our case, given the lesion’s tumor-like radiographic appearance, associated vasogenic edema, and seizure presentation, excision was pursued, with an initial radiographic diagnosis of low-grade glioma. If intraoperative pathology consultation had demonstrated parasitic structures consistent with helminthic infection, our surgical strategy would likely have shifted from an oncological supramarginal resection toward targeted extraction of the parasite and surrounding inflammatory tissue. Because incompletely treated lesions may continue to provoke inflammation or demonstrate migration, gross-total removal remains a reasonable strategy in accessible cortical parasitic lesions.

Although complete excision is widely regarded as definitive therapy in localized and surgically accessible cases, there is no clear consensus that routine postoperative antiparasitic therapy is required following confirmed gross-total removal. In the published series, recurrence is more commonly associated with residual larval tissue rather than omission of adjunctive medication.²⁸ In our pooled analysis of pediatric cases, we did not identify any reported recurrence among patients in whom gross-total resection was documented and who did not receive adjunctive antiparasitic therapy. Nevertheless, antiparasitic agents are frequently administered as a precautionary measure, particularly when viable residual disease cannot be excluded or when multifocal involvement is suspected.² Therefore, postoperative management should be individualized, with close clinical and radiological surveillance.

Lessons

Pediatric cerebral sparganosis is an exceptionally rare parasitic infection that can closely mimic low-grade glioma on neuroimaging, particularly in children presenting from nonendemic regions. Absence of peripheral eosinophilia or a clearly identifiable exposure history should not exclude the diagnosis, as both are frequently absent in pediatric cases. Awareness of characteristic, albeit nonspecific, imaging features, including frontal-parietal predilection, ring or serpiginous enhancement, tunnel-like tracts, microcalcifications, and potential interval lesion migration, may raise diagnostic suspicion but rarely allows definitive preoperative distinction from neoplastic or inflammatory entities. In tumor-like presentations, surgical intervention remains critical, serving both diagnostic and therapeutic purposes, with complete excision combined with antihelminthic therapy offering the most reliable clinical control. This case highlights the importance of maintaining a broad differential diagnosis for pediatric intracranial mass lesions and underscores the need for heightened vigilance for rare parasitic infections to avoid misdiagnosis and ensure optimal outcomes.

Acknowledgments

We used generative artificial intelligence (AI) (OpenAI ChatGPT version 5.0) solely for language refinement and editorial assistance. We critically reviewed, verified, and approved all content and take full responsibility for the accuracy and integrity of the final work. No AI tools were used for data analysis, interpretation, or generation of original scientific content.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Solaroglu, Ucar, Baran, Akyoldas. Acquisition of data: Ucar, Deniz, Kulac. Analysis and interpretation of data: Ucar, Deniz. Drafting the article: Solaroglu, Ucar, Deniz, Baran. Critically revising the article: Solaroglu, Ucar, Deniz, Baran, Akyoldas, Kulac. Reviewed submitted version of manuscript: Ucar, Deniz, Baran. Approved the final version of the manuscript on behalf of all authors: Solaroglu. Statistical analysis: Ucar. Administrative/technical/material support: Solaroglu, Ucar. Study supervision: Baran. Pathology assessment: Eren.

Correspondence

İhsan Solaroglu: Koc University Hospital, Istanbul, Turkey. isolaroglu@ku.edu.tr.