Cerebrospinal fluid cytology in patients with cancer : Minimizing false-negative results

✍ Scribed by Michael J. Glantz; Bernard F. Cole; Lisa K. Glantz; Janet Cobb; Pamela Mills; Andrew Lekos; Beverly C. Walters; Lawrence D. Recht

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 88 KB
• Volume: 82
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/(sici)1097-0142(19980215)82:4<733::aid-cncr17>3.0.co;2-z

✦ Synopsis

Background:

Detection of malignant cells on cytologic examination of the cerebrospinal fluid (csf) is the diagnostic gold standard for leptomeningeal carcinomatosis. the absence of cells is a primary endpoint for most therapeutic trials. unfortunately, false-negative results are common. practical strategies are necessary to remedy this problem.

Methods:

Four physician-dependent variables (csf sample volume, site of csf sampling, processing time, and frequency of csf sampling) were identified, and their contributions to the false-negative rate of csf cytology were evaluated prospectively in 39 patients with leptomeningeal carcinomatosis. retrospective data were analyzed to estimate the importance of these variables in daily practice.

Results:

False-negative csf cytology results correlated with small csf volume (p < 0.001), delayed processing (p < 0.001), not obtaining csf from a site of symptomatic or radiographically demonstrated disease (p = 0.02), and sampling fewer than two times (p < 0.001). in 1 year, 97% of csf specimens at the study institution were of inadequate volume; >25% were processed too slowly.

Conclusions:

False-negative csf cytology results are common, but can be minimized by: 1) withdrawing at least 10.5 ml of csf for cytologic analysis; 2) processing the csf specimen immediately; 3) obtaining csf from a site of known leptomeningeal disease; and 4) repeating this procedure once if the initial cytology is negative.