A 12-year-old boy from a rural area presents with a first generalized seizure. CT shows a single 15 mm cystic lesion in the parietal cortex with an eccentric hyperdense nodule, no surrounding edema, and no enhancement. He is afebrile with no meningism. What is the most likely diagnosis?
- A Calcified stage neurocysticercosis
- B Colloidal vesicular stage neurocysticercosis
- C Viable vesicular stage neurocysticercosis ✓
- D Granulomatous stage tuberculoma
Correct answer: C. Viable vesicular stage neurocysticercosis
Explanation
Neurocysticercosis is the most common parasitic CNS infection worldwide and a leading cause of adult-onset epilepsy in endemic regions like India. In the viable vesicular stage, the live larva causes minimal host reaction: a thin-walled cyst showing the eccentric scolex as the dot-in-cyst sign, without edema or enhancement. The colloidal stage follows larval death and shows ring enhancement with edema, while calcified lesions are solid hyperdense foci. C tuberculoma is a solid enhancing lesion, not cystic.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.