Question
Cysticercus cellulosae in man.
Answer
Cysticercus cellulosae is the larval stage of the pork tapeworm Taenia solium, developing when a human ingests infective eggs (humans thereby acting as an accidental intermediate host), resulting in cysticercosis.
Formation: ingested eggs hatch, releasing oncospheres that disseminate via the bloodstream and encyst in various tissues — muscle, subcutaneous tissue, the eye, and, most importantly, the central nervous system (neurocysticercosis).
Structure: a small, fluid-filled cyst containing a single, invaginated scolex — distinct from the much larger hydatid cyst of Echinococcus granulosus, which contains numerous protoscolices rather than a single scolex.
Clinical significance: neurocysticercosis is a major cause of acquired epilepsy/seizures in endemic regions; can also cause raised intracranial pressure and focal neurological deficits, particularly when the cyst degenerates, provoking an intense inflammatory response.
Diagnosis: CT/MRI (characteristic cystic lesions, sometimes with visible scolex — “hole-with-dot” appearance); serology (ELISA, EITB).
Treatment: albendazole ± praziquantel combined with corticosteroids for viable neurocysticercosis with seizures; antiepileptics for seizure control; surgery for hydrocephalus/mass effect.