Invasion of the leptomeninges by tumour: the differential diagnosis from tuberculous meningitis

Spinal cord involvement in tuberculous meningitis

OBJECTIVES

To summarize the incidence and spectrum of spinal cord-related complications in patients of tuberculous meningitis.

SETTING

Reports from multiple countries were included.

METHODS

An extensive review of the literature, published in English, was carried out using Scopus, PubMed and Google Scholar databases.

RESULTS

Tuberculous meningitis frequently affects the spinal cord and nerve roots. Initial evidence of spinal cord involvement came from post-mortem examination. Subsequent advancement in neuroimaging like conventional lumbar myelography, computed tomographic myelography and gadolinium-enhanced magnetic resonance-myelography have contributed immensely. Spinal involvement manifests in several forms, like tuberculous radiculomyelitis, spinal tuberculoma, myelitis, syringomyelia, vertebral tuberculosis and very rarely spinal tuberculous abscess. Frequently, tuberculous spinal arachnoiditis develops paradoxically. Infrequently, spinal cord involvement may even be asymptomatic. Spinal cord and spinal nerve involvement is demonstrated by diffuse enhancement of cord parenchyma, nerve roots and meninges on contrast-enhanced magnetic resonance imaging. High cerebrospinal fluid protein content is often a risk factor for arachnoiditis. The most important differential diagnosis of tuberculous arachnoiditis is meningeal carcinomatosis. Anti-tuberculosis therapy is the main stay of treatment for tuberculous meningitis. Higher doses of corticosteroids have been found effective. Surgery should be considered only when pathological confirmation is needed or there is significant spinal cord compression. The outcome in these patients has been unpredictable. Some reports observed excellent recovery and some reported unfavorable outcomes after surgical decompression and debridement.

CONCLUSIONS

Tuberculous meningitis is frequently associated with disabling spinal cord and radicular complications. Available treatment options are far from satisfactory.

Diffuse spinal leptomeningeal metastases from prostatic cancer. A case report

A patient with a spinal form of diffuse metastatic leptomeningeal carcinoma from prostatic cancer is reported. The clinical manifestations and diagnosis are discussed, and the literature reviewed.

Routine investigations of the CSF with special reference to meningeal malignancy and infectious meningitis

Usefulness of cell count and concentrations of glucose and total protein in CSF are analysed with regard to the diagnosis of leptomeningeal metastasis from solid and hematological malignancy. A group of patients with pleiocytosis in CSF of non-neoplastic origin served as a reference group. It is concluded that these routine tests have limited value for the determination of the viral, bacterial or neoplastic etiology of meningeal disorders. The most important value of these tests appears to be the discriminating capacity of the finding of an increased number of polymorphonuclear leucocytes, regularly found in patients with acute bacterial meningitis.

Hypoglycorrhachia in leptomeningeal carcinomatosis. A pathophysiological study

We describe a patient with leptomeningeal carcinomatosis in whom no primary malignancy was found in spite of extensive laboratory investigations. The diagnosis was supported, however, by cytological and biochemical CSF examination. Of particular interest in this setting was the low level of glycorrhachia. In order to understand better the mechanism of hypoglycorrhachia, the patient was subjected to I.V. glucose loading; serial samples of blood and CSF were obtained to determine glucose and lactic acid levels. We found that: 1) The low CSF glucose concentration was not increased by I.V. infusion of sugar; 2) the high basal CSF lactic acid level was not further stimulated by I.V. glucose loading. These data suggest that hypoglycorrhachia was not due to an increased utilization of glucose by neoplastic cells that infiltrate the meninges but to abnormal transport of glucose from blood to CSF.

Leptomeningeal spread of breast cancer: report of case and review of the literature

Leptomeningeal metastasis--so-called "meningeal carcinomatosis"--of breast carcinoma has become a problem of some magnitude in recent years, in part a result of the increasing use of combination chemotherapy in the treatment of this disease. Early clinical diagnosis, based on the recognition of multifocal neurologic dysfunction, and aggressive therapy combining irradiation to severely symptomatic sites with intrathecal chemotherapy are considered primordial in order to improve the poor prognosis of the untreated lesion. This is especially true in view of the fact that meningeal metastasis often occurs as the sole site of recurrence in an otherwise asymptomatic patient. Hence, relief of neurologic symptoms can provide meaningful palliation and an occasional long-term survivor. If meningeal metastasis continues to increase in breast cancer patients, prophylactic CNS treatment may become a consideration.

Mucus-secreting 'signet-ring' cells in CSF revealing the site of primary cancer

A case is reported of leptomeningeal carcinomatosis in which identification of mucus-secreting 'signet-ring' carcinoma cells in the CSF allowed diagnosis of an otherwise asymptomatic gastric cancer. When lumbar puncture is performed, careful cytological examination of the CSF should be carried out in any undiagnosed patient with neurological symptoms and signs.

Diffuse involvement of the leptomeninges by tumour--a clinical and pathological study of 63 cases

The clinical and pathological features of 63 cases of post-mortem-proved diffuse infiltration of the leptomeninges by tumour are presented. A wide variety of tumours of the nervous system, both primary and secondary, was found to give rise to such involvement, with adenocarcinoma having a particular propensity to behave in this manner. Dysfunction of cranial and spinal nerves, a confusional state and headache were prominent clinical features. Examination of the cerebro-spinal fluid was found to be less useful diagnostically in cases of primary tumours of the nervous system with leptomeningeal involvement than in cases of diffuse infiltration of the meninges by carcinoma.

Meningeal carcinomatosis

An anatomopathologic study of 18 cases of pure meningeal carcinomatosis is presented. In five of these cases, the brain, spinal cord, choroid plexuses, cerebral vessels, and prevertebral soft tissues, including the lumbosacral nerve plexuses and ganglia, were examined microscopically in an attmept to determine the routes of tumor spread. Our results suggest that the malignant cells reach the cerebrospinal leptomeninges via perineural, endoneural, and perivascular lymphatics and sheaths through the intervertebral and possibly cranial foramina. Involvement of the choroid plexuses appears to be secondary to, rather than the avenue for, leptomeningeal carcinomatosis, with the tumor cells reaching the choroid plexuses via the perivascular sheaths of choroidal vessels. Leptomeningeal carcinomatosis was the only manifestation of metastatic spread beyond regional lymph nodes in about 40% of all reported cases in which this information is available. This implies that radiation or other forms of local therapy to the cerebrospinal leptomeninges may provide an effective means of palliation in many of these cases.

Primary leptomeningeal sarcomatosis. Clinicopathological report of six cases

6 autopsy cases of primary leptomeningeal sarcomatosis are presented as a distinct nosological entity with a variable clinical picture and morphology in 5 males and 1 female. The clinical course from onset of symptoms till death ran for only a few weeks in most cases. 2 infants showed brain tumor symptoms and signs. 2 patients of advanced age presented a polyradiculoneuritic syndrome and 2 young adults had spinal cord compression symptoms and a mixed clinical form. In almost all cases, clinical symptoms and signs were for most of the course confined to one part of the neuraxis. The CSF was distinctly abnormal in all cases, showing elevated protein, depressed glucose and pleocytosis of variable extent. CSF sediment was investigated in 3 cases in all of which malignant tumor cells were found so a diagnosis of malignant meningeal tumor was made during life. Electron microscopy of CSF cells in 1 case confirmed the primitive character of the tumor cells. Complete autopsies revealed absence of any neoplasm outside of the CNS. Gross meningeal involvement was visible in all cases. Histologically, 3 tumor types were distinguished: polymorphic cell sarcoma, an undifferentiated form, and fibrosarcomatosis. Clinical data are analyzed in order to distinguish the condition from other neoplasms or infectious, especially tuberculous meningeal infiltrations. CSF cytology studies are considered the most useful step in clinical diagnosis. Neuropathological features are reviewed with stress on differentiation from malignant lymphomas of the CNS, diffusely spreading medulloblastoma, meningeal melanoblastosis and gliomatosis. The origin of meningeal sarcomatosis cells is briefly discussed. The use of the term "meningeal meningiomatosis" for this condition is deprecated.

Meningeal carcinomatosis and blindness

The clinical syndrome of meningeal carcinomatosis includes headache, dementia, radiculopathy, and cranial nerve palsies. Blindness may be the first, or most prominent, symptom. When blindness occurs in adult life, meningeal carcinomatosis should be included in the differential diagnosis, even in the absence of other symptoms and in the absence of known malignancy. Although all pathophysiological mechanisms of the blindness in meningeal carcinomatosis have not yet been elucidated, optic nerve involvement by meningeal tumour-cuffing, by chronic papilloedema, and by direct tumour infiltration represent the likeliest causes. In the neuropathological analysis of such cases, the importance of analysing the intra-orbital portion of the optic nerves, in addition to the portions of the optic nerve and chiasm usually examined at routine necropsy, is emphasized. A case is described to illustrate this point, with the only pathological abnormality in the optic nerves being found within 6 mm of the retina.