[Leptomeningeal gliomatosis with high levels of adenosine deaminase in the cerebrospinal fluid].

A 61-year-old man developed disturbance of consciousness for 2 weeks. He showed neck stiffness and hyporeflexia. Analysis of his cerebrospinal fluid (CSF) revealed pleocytosis and markedly reduced glucose contents. Adenosine deaminase (ADA) levels in the CSF were elevated (28.8 IU/l). Brain magnetic resonance imagings showed enhancement of the leptomeninges. Tuberculous meningitis was considered, but antituberculous drug was not effective. Repeated cytological analysis of the CSF demonstrated atypical cells with enlarged unevenly distributed nuclei and immunoreactive with glial fibrillary acidic protein. We diagnosed him as leptomeningeal gliomatosis. CSF ADA may be elevated in this rare disorder, and here we emphasize that repeated cytological analysis with immunohistochemical staining was useful for diagnosis.

Primary diffuse leptomeningeal gliomatosis: an autopsy case and review of the literature.

We report a case of primary diffuse leptomeningeal gliomatosis (PDLG) in a 76-year-old male presenting with confusion, dysarthria, diplopia, lumbal pain and headaches of recent onset. Neurological examination revealed nuchal rigidity and bilateral sixth cranial nerve palsy. The cerebrospinal fluid showed a marked hyperproteinorachia (4711 mg/L) and mild cytorachia (5-10 leucocytes/mm3) with a few atypical lymphoid cells. On admission, brain CT scan and MRI demonstrated diffuse and nodular leptomeningeal contrast enhancement predominant at the skull base and several osteolytic lesions in the right parietal bone. Extensive serological studies for infectious, autoimmune or neoplastic diseases were negative. The work-up diagnosis was neurosarcoidosis or multiple meningeal and osseous metastases of an unknown primary cancer. Surgical biopsy of the right parietal bone lesion showed only fibrous tissue with no evidence of tumour or inflammation. The patient was treated with high dose corticosteroids but its neurological status progressively worsened and he died of aspiration pneumonia 35 days after admission. Post-mortem examination revealed a PDLG, a rare fatal tumour with about 60 cases reported. PDGL is characterized by the diffusion of neoplastic glial cells throughout the leptomeninges without evidence of a primary intra-parenchymal lesion. Recognition of this rare brain tumour is important as recent reports suggest that radiotherapy and chemotherapy can improve patient survival.

Diagnostic value of immunocytochemistry in leptomeningeal tumor dissemination.

Differentiating chronic aseptic meningitis from leptomeningeal carcinomatosis or gliomatosis can be difficult, particularly when the differentiation is based solely on routine cytologic examination. The diagnosis of cerebrospinal fluid tumor dissemination in at-risk patients requires cytologic examination of cerebrospinal fluid and radiography of the leptomeninges. Routine cytologic examination alone has proven less than desirable, in most instances providing confirmation in as little as 50% of cases in the first lumbar puncture. This percentage increases to 85% to 90% after multiple lumbar punctures. We retrospectively reviewed 2 cases of leptomeningeal dissemination (one gliomatosis, the other carcinomatosis) with initial false-negative test results. However, after further examination of the cerebrospinal fluid by selected battery of immunocytochemical stains, both cases were identified as positive for malignancy (ie, false negatives). Immunocytochemistry can be useful in distinguishing chronic aseptic meningitis from leptomeningeal carcinomatosis or gliomatosis in patients at risk or when abnormal cells are seen on routine cerebrospinal fluid cytologic examination.