A biopsy to confirm the diagnosis and also to remove the majority of the lesions in the cauda equina was performed. 

Histology:

On the biopsy microsection, a tapeworm-like parasite was seen, surrounded by a pink serrated border, stained with PAS dye. Inside, there are structures of the digestive tract. Some foci of calcification, inflammatory cell infiltration, many eosinophils. No malignant cells were found.

Histopathological images are consistent with tapeworm parasites.

Treatment:

The patient was treated with antiparasitic drugs. 

Discussion:

Intraspinal forms of neurocysticercosis are rare with the incidence varying from 1% to 3%. These lesions are often accompanied by those in the brain due to cerebrospinal fluid dissemination.

Isolated spinal cysticercosis, like this case, is extremely rare. 

The majority of spinal cysticercosis is extramedullary intradural form. MRI features include cystic, diffuse arachnoiditis or a mixture of both. 

• cystic lesions: typically a well-defined border cyst. Scolex can be seen as a mural nodule that shows enhancement after contrast. 
• arachnoiditis (like this case): rare, probably from inflammatory reaction due to the rupture of the cysticercosis cyst into subarachnoid space. Lesions are diffuse with heterogeneous enhancement.

Differential diagnosis includes myxopapillary ependymoma (usually more circumscribed and more homogenous and enhancement), leptomeningeal carcinomatosis, arachnoiditis from other causes and schannomatosis (e.g. NF2).