Specific findings in cerebrospinal fluid cytology

Objective To analysis one institution’s cerebrospinal fluid (CSF) cytology results from 3 922 specimens. Methods A retrospective study of 3 922 CSF cytology specimens generated between 1984 and 2003. The May-Grunwald- Giemsa’s stain was applied to routine cytology, while PAS or immunno-cytochemical stain for tumor markers were used in some specimens. Results A total of 3 922 CSF specimens were interpreted. Specific findings were identified in 55 specimen. Specific infectious organisms were identified in specimens: cryptococcus was the most common infectious agent observed ( n =5), and Fusarium was identified in a female with breast cancer. 49 cases were positive for malignant cells. Diagnosis included the metastatic carcinomas ( n =26), metastatic lymphoma/leukemia ( n =7), primary central nervous system neoplasms ( n =10), including primary CNS malignant lymphoma ( n =4), Germinoma ( n =4) and glioblastoma ( n =2) and also the malignant unclassified neoplasms ( n =6). Carcinoma cells showed positive staining for epithelial membrane antigen and /or cytokeratin immunostain. Lymphoma cells showed positive staining for CD34, LCA and (or) CD20. Conclusion Although specific findings in CSF cytology account for a small percent of the total specimens, they are of great significance in reaching final diagnoses. The most commonly identified infectious organisms were Cryptococcus. The most commonly identified malignancy was metastatic neoplasms. CNS fusarosis might be identified by CSF cytology.