Case Report: Moving Tumor-Like Foci Behind Refractory Epilepsy-Cerebral Sparganosis Successfully Treated by Surgery After Failure of Praziquantel Treatment

Abstract

Cerebral sparganosis is clinically non-specific and easily misdiagnosed, exposing patients to the risk of severe brain damage and neurological dysfunction caused by actively migrating larvae. Diagnostic biomarkers from typical cases can help to establish an early diagnosis and proper treatment. We present a 25-year-old woman who suffered from 9 years of refractory epilepsy and was misdiagnosed with glioma and subjected to surgery. The postoperative pathology confirmed granuloma, and the tumor-like foci reappeared 3 months later. Along with the "tunnel sign" on MRI, cerebral sparganosis was suspected and confirmed by positive serum and cerebrospinal fluid antibodies against Spirometra mansoni. The patient visited us after a failure of four cycles of praziquantel treatment, recurrent seizures and hemiplegia with basal ganglia foci. Craniotomy was not carried out until the larva moved to the superficial lobe on follow-up MRIs, and pathology revealed sparganosis granuloma. The patient became seizure-free and recovered myodynamia but had long-lasting cognitive dysfunction due to severe brain damage. This case indicated the importance of tunnel signs and moving tumor-like foci on MRI as diagnostic clues of cerebral sparganosis. An early diagnosis is vitally important to avoid severe neural dysfunction by the long-living and moving larvae. Surgical removal of the larva is a critical remedy for cases failed by praziquantel treatment.

Keywords: Spirometra mansoni; cerebral sparganosis; craniotomy; refractory epilepsy; tunnel sign.

Figure 1

Neuroimaging results of cerebral sparganosis in the case. (A) Six years after the onset (aged 22), tumor-like occupation foci at the right frontal lobe with edema and irregular enhancement causing midline shift on MRI before the first operation. Note that regular ring-shaped enhancement appeared on the sagittal view (the rightmost figure) (Left to right: T1, T2, axial T1 post gad, sagittal T1 post gad). (B) Three months after the operation, the enhanced foci shifted to the left frontal lobe, and postoperative encephalomalacia occurred at the original right frontal lobe on her follow-up MRI images (Left to right: axial T1 post gad, sagittal T1 post gad (left side), sagittal T1 post gad (right side), coronal T1 post gad). (C) Five months after the operation, a typical tunnel sign at the left frontal lobe was found on both axial and sagital view of her repeated MRI with enhancement (Left to right: T1, T2, axial T1 post gad, sagittal T1 post gad). (D) Three years after the operation (aged 25), the patient came to our center with left side paralysis. Restricted enhancement foci in the right centrum semiovale and basal ganglia with punched-out and tunnel-like presentation were found at the right basal ganglia (Left to right: axial T1, T2, T2 FLAIR, T1 post gad). (E) Four years after the operation (aged 26), the larva moved to the superficial area of the right frontal lobe where surgical removal became possible (Left to right: axial T1, T2, T2 FLAIR, T1 post gad). (F) 16 months after the removal operation (aged 28), MRI revealed softened foci, gliosis and shrinkage of the parenchyma at the right frontal and parietal lobe. No focal or meningeal enhancement was found (Left to right: axial T1, T2, T2 FLAIR, T1 post gad).

Figure 2

Larval samples and the pathologic results of cerebral sparganosis in the case. (A) Larva samples acquired during the operation in our hospital. Necrotic objects split into band shaped sections from the larva were wrapped in surrounding brain tissue. The larva adhered to the surrounding brain tissue because of severe inflammatory reactions and therefore was not fully presented. (B,C) Images of microscopy inspection of the sample under low power (HE, ×100) and high power (HE, ×400) are also presented, which are characterized by irregular striped necrotic objects with inflammatory infiltration of multinucleated giant cells and the formation of foreign body granulomas. Calcareous corpuscles, which were characterized by basophilic vacuolated structures in the larva body, were indicated with black arrows. (D) Coronal section of the necrotic object (HE, ×100).