Search

Incidence of both primary and secondary central nervous system (CNS) malignancies are increasing, yet detection and diagnosis of which remains challenging. Neurological examination, CSF cytology and neuroimaging each offer diagnostic value, however, individually, each method has relatively low sensitivity. CSF cytology is often routinely requested as part of the diagnostic work-up. Therefore, we reviewed the value of CSF cytology in predicting CNS neoplastic process.We systematically analysed 296 patients who had had CSF cytology. All consecutive patients over the last 2 years were included. The 12 patients positive for CSF cytology were also found to have concurrent; clinical findings (92%), radiological findings (92%), or both (83%). In no patient CNS malignancy was identified by CSF cytology alone. Additionally, only 7 of the 12 CSF positive cases were collected by means of lumbar puncture, the rest were carried out during neurosurgical procedures.We conclude that if there is neither clinical findings nor abnormal neuroimaging, assessing CSF cytology does not contribute towards diagnosis of CNS malignancy. Yield of CSF cytology is high when both clinical and radiological evidence are present. Where neuroimaging is normal but suspicion remains, the low sensitivity of the CSF-cytology would make it a weak corroborator to exclude malignancy.

Background The identification of central nervous system (CNS) involvement by malignancies, using cytological analysis of CSF, is crucial for the appropriate treatment of patients.1 The aim of this study was to identify CSF specimen characteristics that have the highest diagnostic yield. Methods We conducted a retrospective review of all CSF specimens submitted for cytological analysis at Cork University Hospital from January 2010 to December 2011. Results 598 CSF samples were obtained from 390 people. The difference in volume between the diagnostic categories of equivocal (29%), inadequate (17%), positive (5%) and negative (48%) was found to be statistically significant, p-value Discussion Conventional cytology has shown high specificity but low sensitivity, being positive in 45% to 94% of initial specimens.1 Our study shows that factors increasing the likelihood of a definite result include a sample volume greater than 3 ml, and repeating sampling.

Cerebrospinal Fluid (CSF) cytology is thought to be the gold standard for diagnosing neoplastic meningitis. The accuracy of this test is important since it may determine whether or not a patient is given intra-thecal chemotherapy. Previous studies indicate that >10.5ml of CSF should to be collected in order to achieve a false negative rate of ≤3% and European Guidelines on CSF analysis recommend that this be the minimum volume collected.275 consecutive CSF cytology samples from the West Midlands regional clinical neuroscience and haemo-oncology centre were audited to see how many met this standard.The median volume of CSF sent for cytology was 2 ml (IQR1 to 5 ml). In fact only 2 (10.5 ml, though a further 22 (8%) of samples were close at 10 to 10.5 ml.A re-evaluation is needed of the way in which neoplastic meningitis is diagnosed in the West Midlands. If newer techniques are sufficiently sensitive to allow an acceptable false positive rate with a lower volume of CSF, local guidelines should be drawn up which take this into account, otherwise the doctors collecting the samples need to be educated and monitored to ensure they meet the established standard.

Introduction CSF Cytology specificity and sensitivity is influenced by sample volume and time to fixation. A CSF volume of over 10 mls decreases the possibility of a false negative result and improves accuracy. 1 2 The diagnostic sensitivity of the test is also dependant on being performed on patients with a reasonable clinical suspicion of malignancy/leptomeningeal involvement. CSF analysis remains the most definitive test for detecting leptomeningeal metastasis. We audited the results of lumbar punctures performed on neurology patients on the planned investigation unit between May and July 2012. This showed that cytology was performed routinely on every CSF sample collected. Over 96% of the samples contained less than 10 mls with over 90% of the samples containing less than 3 mls. There were no malignant cells detected in all samples. 2 of the 49 samples had no clinical information. The results were presented at the local neurology departmental meeting and several interventions were instituted with appropriate induction of the junior doctors involved in taking the samples. CSF Cytology was only performed if there was history of malignancy, meningeal enhancement on MRI, or if it was specifically requested by the neurologist who reviewed the patient in clinic. It was recommended that at least 10 mls of CSF was collected for cytology samples. The sample was to be taken immediately to the lab after collection with appropriate clinical information included. After the interventions, the audit was repeated. Methods Data of the results of all lumbar punctures performed on the planned investigation unit between October 2012 and January 2013 were reviewed. Data was obtained through cerner (an electronic health record system). Further clinical information was also obtained from letters, discharge summaries and notes. All cytology samples were processed in the same lab using a standardised method. Results 49 successful lumbar punctures were performed during the three month period. CSF Cytology was requested and processed on 8 patients CSF. 100% of the samples contained over 3 mls of CSF. 75% of the samples had a volume over 10 mls. No malignant cells were detected on all samples. All of the requests had appropriate clinical information on the request form except one which had no clinical information. Conclusion Our results showed a significant improvement in sample volume sent to the lab. Also there was a reduction in unnecessary cytology samples being sent. CSF Cytology sample processing takes 1 hour to process and costs around £70 per sample. This resulted in a reduction of cost from around £3430 per three month period (May to July 2012) to around £560 per three months (October 2012 to January 2013). Information regarding CSF cytology sample collection and requesting should be included as part of the induction of junior doctors.

Introduction Leptomeningeal carcinomatosis is a rapidly progressive disease for which early diagnosis is vital. Cytological analysis of the cerebrospinal fluid (CSF) is the gold standard, however sensitivity is significantly impaired by inadequate volumes and delays in formulin fixation. Methods We developed and disseminated a CSF cytology guideline pack, including a fixative bottle, with education sessions. We retrospectively identified all cytology analysis for 6 months before and after the introduction of the pack to assess the impact of the intervention. Results We identified 83 and 66 patients before and after the introduction of the intervention respectively. After the intervention there was a significant increase in the median sample volume collected (4.2 ml and 6.7 ml respectively, p=0.0003) and the proportion with at least 10 ml collected (13 (16%) and 26 (39%), p=0.001) and the proportion fixed in formalin within 30 min (14 (17%) and 49 (74%), p=0.0001). There was also a trend towards a greater proportion of samples being suggestive or diagnostic of malignancy (9 (15%) vs 5 (6%) respectively, p=0.089). Moreover, if >6 ml was collected the OR of identifying malignant cells was 2.88 (p=0.01); if >10 ml was collected the OR was 3.87 (p=0.01). Conclusion In conclusion the introduction of a simple CSF cytology pack and education sessions resulted in significant improvements in both the volume and fixation of CSF samples and was associated with a trend towards an increase in diagnostic sensitivity, which is critical for appropriate treatment.