CEREBROSPINAL-FLUID CYTOLOGY - AN 11-YEAR EXPERIENCE WITH 5951 SPECIMENS

Objective. - Cerebrospinal fluid (CSF) diagnoses encompass a wide spec trum of conditions. The authors review one institution's CSF cytology results over an Ii-year period. Design and Setting. - A retrospective study of 5951 CSF specimens generated between 1985 and 1995. Specimens from pediatric patients (< 19 years of age) from the same time period were separately identified. Results. - A total of 5561 adult and 390 pediatric CSF specimens were interpreted. A diagnosis of ''negative fo r malignant cells'' was assigned in 5171 (93%) of the adult cases and in 351 (90%) of the pediatric cases. Specific infectious organisms wer e identified in 26 adult specimens and one pediatric specimen. Cryptoc occus was the most common infectious agent observed (n = 23 adults), a nd Toxoplasma was the sole pediatric infectious agent. Two hundred sev enty-six (5%) adult cases and 31 (8%) pediatric cases were positive fo r malignant cells. Diagnoses ineluded metastatic tumors (adult, 140 [5 1%]; pediatric, 0); lymphoma/leukemia (adult, 112 [41%]; pediatric, 4 [13%]); malignant unclassified neoplasms (adult, 9 [3%]; pediatric, 0) ; and primary central nervous system neoplasms (adult, 12 [4%]; pediat ric, 27 [87%]). Medulloblastoma was the most common pediatric neoplasm (n = 21). There were 105 (2%) adult cases and 8 (2%) pediatric cases with atypical cells present. Atypical lymphoid cells were the most com mon type in adult cases (53%). Conclusions. - ln our experience, infec tious agents were rarely identified in pediatric CSF specimens. In adu lt specimens, the most commonly identified organisms was Cryptococcus. Primary central nervous system neoplasms accounted for a higher perce ntage of CSF specimens in the pediatric population than in the adult p opulation. The most commonly identified malignancy in adults was metas tatic neoplasms, and in children, medulloblastoma.