L-PGDS is mainly produced in the choroid plexus, leptomeninges
, and oligodendrocytes, and then secreted into the CSF.
The presence of these two abnormalities represents a phenotypic marker for more profound melanotic infiltration of the leptomeninges
, which increases the risk of malignant transformation.
Gross brain examination revealed opaque leptomeninges
The painful asymmetric paraparesis in our patient was consistent with subacute painful meningoradiculitis seen in the early dissemination period of neuroborreliosis due to the presence of lymphocytic cell increase in the LP, polyradiculopathy in the EMG and contrast enhancement in leptomeninges
, and conus medullaris and cauda equina fibers in the lumbar MRI examination.
The dura, pia and arachnoid of the brain tissue and/or leptomeninges
that are defined as a bone defect with herniation continuing to the cranial cavity are clearly separated from the surrounding encephalocele (1).
Based on a review by Dispenzieri and Kyle, intracranial plasmacytomas or myelomas can be classified into four groups: (1) those extending from the skull pressing inward, (2) those growing from the dura mater or the leptomeninges
, (3) those arising from the mucous membranes of a nasopharyngeal plasmacytoma, and (4) intraparenchymal lesions without evidence of extension from any of these other three sites .
MCs are also present in the CNS, mainly located in the perivascular spaces and along the leptomeninges
Autopsy revealed a necrotizing infection in the leptomeninges
of the brain and spinal cord and numerous microabscesses of the liver.
For possibility of leptomeningeal metastasis, biopsy of the brain, and leptomeninges
Her initial CT brain with contrast was reported as multiple metastatic brain deposits in leptomeninges
, suprasellar, and fourth ventricle.
It is suspected that cancer cells may reach the leptomeninges
through hematogenous spread, direct invasion from parenchymal lesions, or spread along the perineurium from cranial or spinal nerves.
[4,5] The MRI show that temporal lobe abnormalities such as hyperintense signals on [T.sub.2]-weighted or fluid-attenuated inversion recovery (FLAIR) sequences, atrophic temporal-limbic structures on [T.sub.1]-weighted images, typically without contrast-enhancement in the brain parenchyma or leptomeninges
.  Limbic encephalitis is a rare paraneoplastic syndrome which is associated with cancer.