Cerebrospinal fluid (CSF) examination can be used to verify the presence of primary malignancies as well as cases of leptomeningeal carcinomatosis. Because of its importance, there have been several studies concerning the sensitivity of CSF cytology.
Current methods for detection of leptomeningeal disease is the combined use of cranio-spinal MRI, and cerebrospinal fluid cytology from a post-operative lumbar puncture. Low et al., hypothesized that CSF taken at the start of surgery, either from an external ventricular drain or neuroendoscope will have equal sensitivity for positive tumour cells, in comparison to lumbar puncture. Secondary hypotheses include positive correlation between CSF cytology and MRI findings of LMD. From a clinical perspective, the key aim of the study was for affected paediatric patients to avoid an additional procedure of a lumbar puncture, often performed under anaesthesia after neurosurgical intervention.
This is single-institution, retrospective study of paediatric patients diagnosed with malignant brain tumours. Its main aim was to compare cytological data from CSF collected at the time of surgery versus data from an interval lumbar puncture. In addition, MRI imaging of the same cohort of patients was examined for leptomeningeal disease and corroborated against CSF tumour cytology findings.
Thirty patients are recruited for this study. Data analysis demonstrates a statistically significant association between the intra-operative CSF and LP sampling. Furthermore, this results also show for significant correlation between evidence of leptomeningeal disease on MRI findings versus intra-operative CSF positivity for tumour cells.
Although this is a retrospective study with a limited population, the data concurs with potential to avoid an additional procedure for the pediatric patient diagnosed with a malignant brain tumor 1).
385 CSF cytology samples from 42 patients were collected from ventricular catheter and reservoir. CSF cytology of all patients was examined more than two times with immunocytochemistry for cytokeratin.
Primary neoplastic sites and histologic types of patients' metastatic cancer were diverse. The overall sensitivity for detecting malignancy was 41.3%. Even within short-term intervals, diagnoses frequently changed.
The results were inconsistent, with low sensitivity, when compared to the results of previous studies. However, CSF evaluation can still provide valuable diagnostic and prognostic information because adjuvant treatments are now routinely performed in patients with CNS metastasis. Negative CSF cytology results should not be ignored, and continuous CSF follow-up is essential for following the clinical course of patients with metastatic cancer involving the CNS 2).