Cerebral hydatid disease with serpent sign, calcifications, and peripheral enhancement

A 44-year-old male with an unremarkable medical history was admitted to the hospital with episodes of headache in the left frontal region for 6 months. Magnetic resonance (MR) imaging of the brain was performed and revealed a mass in the left frontal lobe. The lesion demonstrated high-signal-intensity matrix associated with curvilinear low-signal-intensity regions on T2-weighted images and hypointense heterogeneous signals on T1-weighted images. The capsular wall of the lesion was isointense on T1-weighted images and hypointense on T2-weighted images. It revealed enhancement on postcontrast T1-weighted imaging, whereas the internal matrix did not enhance. Susceptibility-weighted imaging (SWI) demonstrated hypointense signal intensity areas in the lesion. The mass was completely hypointense on diffusion weighted image (DWI) (Fig. 1). A CT image of the thorax and abdomen was performed for screening but was normal. Surgery was performed. The mass was completely resected. No postoperative complications were noted, and the patient was discharged in good general condition. Histopathologic examination of the specimen demonstrated the outer layer of hydatid cyst wall consisting of variable inflammatory cells with sharp demarcation from the adjacent brain parenchyma. The PAS (periodic acid–Schiff) positive middle layer of the cyst wall was avascular, eosinophilic and laminated. There were calcified protoscolices within the disrupted brood capsule (Fig. 2). He was stable and well-improved in the follow-up period. …