Neuroimaging and cerebrospinal fluid cytology in the diagnosis of leptomeningeal metastasis

Abstract

The diagnosis of leptomeningeal metastasis is often difficult and usually requires the demonstration of malignant cells in the cerebrospinal fluid. Neuroimaging, however, may establish or support the diagnosis in some patients. Radiographic abnormalities consistent with or suggestive of leptomeningeal metastasis include leptomeningeal, subependymal, dural, or cranial nerve enhancement; superficial cerebral lesions; and communicating hydrocephalus. We evaluated 137 cancer patients with clinical symptoms suspicious for leptomeningeal metastasis with neuroimaging or cerebrospinal fluid cytology or both. Neuroimaging findings were abnormal in 70 of 128 tested patients; cytology was performed in 58 of these 70 and the results were positive in 37. Conversely, cytological findings were positive in 53 of 115 tested patients; neuroimaging was performed in 49 of these 53 and the findings were abnormal in 37 (26/29 solid tumors and 11/20 hematological tumors). Of the total series of 137 patients, leptomeningeal metastasis was diagnosed in 77; in 24 (31%) the diagnosis was made on the basis of clinical picture and abnormal neuroimaging alone. Neuroimaging is a valuable tool in the investigation of leptomeningeal metastasis in the cancer population, and the presence of typical clinical features together with appropriate neuroimaging abnormalities is adequate to make the diagnosis of leptomeningeal metastasis even if cerebrospinal fluid cytological results are negative.

Neoplastic Meningitis

“…Subependymal involvement of the ventricles often results in ventricular enhancement. Some changes, such as cranial nerve enhancement on cranial imaging and intradural extramedullary enhancing nodules on spinal MRI (most frequently seen in the cauda equina), can be considered diagnostic of NM in patients with cancer [47]. Lumbar puncture itself rarely can cause a meningeal reaction, leading to dural-arachnoidal enhancement, so imaging should be obtained preferably prior to the procedure [48].…”

“…MR-Gd still has a Ն30% incidence of false-negative results, so a normal study does not exclude the diagnosis of NM. On the other hand, in cases with a typical clinical presentation, abnormal MR-Gd alone is adequate to establish the diagnosis of NM [32, 42,46,47].…”

Laboratorial diagnosis of lymphocytic meningitis

“…Currently, the diagnosis generally is made after the onset of neurological manifestations and heralds a rapidly-fatal course for most patients. Immunocytochemistry techniques, immunophenotyping and biochemical or immunological markers can help in this diagnosis [56,57,66,[71][72][73][74][75][76][77][78]. The analysis of CSF biochemical and cellular characteristics, although not specific for the diagnosis of malignant involvement of the CNS, is important and can help with the diagnosis of CNS neoplasms, when associated with other clinical or biomarker characteristics.…”

Cerebrospinal fluid cytological and biochemical characteristics in the presence of CNS neoplasia

“…Currently, the diagnosis occurs generally after the onset of neurologic manifestations and heralds a rapidly fatal course for most patients 27 . Imunocytochemistry techniques, immunophenotipagem and biochemical or immunologic markers can help in this diagnosis 7,8,10,[27][28][29][30][31][32][33][34] . The analysis of CSF biochemical and cellular characteristics, although not specific for the diagnosis of malignant involvement of CNS, are important and can help for the diagnosis of CNS neoplasm when associated with other clinical or biomarker characteristics.…”