Improving Standards in Cerebrospinal Fluid Reporting: 21-Years Retrospective Review

Background : Diseases affecting the central nervous system and meninges can be detected by different modalities, and the choice of analysis(es) will depend on the clinical question. Morphological detection of malignant cells remains the gold standard for many types of malignant diseases. We wanted to investigate the distribution of samples with benign results, uncertain diagnoses, and malignant diagnoses in cerebrospinal fluid. Materials and methods : Spinal fluids received by the Department of Pathology, Oslo University Hospital, in the period January 1, 2000–December 31, 2021, were identified by searching the statistics program linked to the computer program used to report test results. Results : 9669 specimens from 6884 patients met the inclusion criteria. Age ranged from <1 year to 95 years, with a mean age of 44.3 years and 54% were male. 6429 (66.5%) specimens were without findings. 1609 (16.6%) of the specimens had inflammation, 345 (3.6%) were uncertain for malignancy, and 516 (5.3%) were malignant. 770 (8.0%) were considered unsuitable for further analysis. 85.9% of the malignant cases were lymphoproliferative neoplasms. Interpretation : Microscopic examination of spinal fluids is an important modality in the investigation and diagnosis of diseases of the meninges and central nervous system.