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Centrifugal cytology: A new technique for urine cytology
CENTRIFUGAL CYTOLOGY: A NEW TECHNIQUE FOR URINE CYTOLOGY M. BONDHUS, R. LEIF,
M.D.
A. NG, M.D.
PH.D.
D. BOBBITT, J. LOCKHART,
M. SILVERMAN,
C.T.
V. A. POLITANO,
M.D.
M.D. M.D.
D. HINDMAN
From the Departments of Urology and Pathology, University of Miami, School of Medicine, Jackson Memorial Hospital, and the Papanicolaou Cancer Research Institute, Miami, Florida
ABSTRACT-A new technique, centrifugal cytology, appears to have a high recovery rate of malignant cells from voided urine specimens resulting in a high probability of early disease detection and should be considered a good supplement to cytoscopic evaluation of high-risk populations.
Exfoliated urine cytology has proved to be a useful tool in the diagnosis and management of bladder carcinoma. However, like all diagnostic screening procedures, its usefulness is proportional to the probability of disease detection versus its cost. Because of the low incidence of positive specimens and the relative high cost of preparing urine cytology, large scale screening has not been advocated. A new technique, centrifugal cytology, developed by Doctor Robert Leif and co-workers,’ appears to be simple, relatively inexpensive, and has a nearly quantitative recovery of cells on a glass slide with minimal cell overlap resulting in a high probability of early disease detection The major innovation with this new technique is a higher recovery of abnormal ceils in a smaller area resulting in a rapid and highly sensitive screening procedure. All other current cytology centrifugation techniques used to trap cells are often complex, tedious, and result in distortion of cells, making accurate evaluation by the pathologist difficult. The purpose of this article is to show that centrifugal cytology is more efficacious than other standard commonly used cytologic centrifugation techniques. 432
Material and Methods The centrifugal cytology technique can be performed on freshly voided specimens or specimens stored in a 10% transport medium* for stabilization. After preliminary routine centrifugation, the samples are resuspended in Mucolexx* solution. The Leif Centrifugal Cytology Bucket Rotor1 consists of a sample chamber and a carrier unit shown in parts 1 and 2 of Figure 1. The samples are placed in the sample chamber (parts 3 and 4). Centrifugation at 1,500 r-pm for ten minutes is then performed. Following this, a syringe with a 21-gauge needle is inserted in the small hole of the sample chamber and the supernatant removed (part 5). The fixative (4% glutaraldehyde solution) is then added to the sample chamber (part 6) and recentrifuged at 1,500 rpm for fifteen minutes. The slide is then removed from the bucket and stained, using Papanicolaou stain protocol.2 To prove the diagnostic accuracy of centrifugal cytology, two types of studies were performed. The first compared cell recovery rate of centrifugal cytology to the cytocentrifuge ‘Lerner Laboratories Division of Shandon Scientific, Pittsburgh, Pennsylvania. ICoulter Electronics, Inc., Hialeah, Florida.
UROLOGY I NOVEMBER 1986 / VOLUMEXXVIII, NUMBER5
FIGURE1. Technique for centrifugal cytology: (1 and 2) sample chamber and carrier units. (3 and 4) Placement of samples in sample chamber. (5) Ajt er centrijugation, 21-gauge needle is inserted in small hole OJ chamber Supernatent is removed. (6) FOUT per cent glutaraldehyde solution is added (‘GOT fixation) ana recentrijugation is peTjormed. TABLE I. Cell Type
WBC
Centrifugal cytology/ cytocentrifuge
126
Ratio of corrected
FtBC Transitional 60
Squamous
Columnar
Histiocytes
Abnormal
Malignanl
35
31
161
56
40
90
which is another common and popular centrifugation technique. 3 This was done using fourteen paired urine specimens, calculating total cell counts and ratios of recovered cells after the split samples were corrected for differences in volume. The results were then compared as to the type of cells recovered and a ratio calculated for each type of cell. The second part of the study was performed using 73 known positive bladder cancer patients and 14 cystoscopically known negative patients (post-treatment patients). Calculation of false positive and false negative rates was then performed. A comparison study with cytocentrifuge technique using known positive bladder cancer patients was also performed.
and normal and abnormal bladder cells are alsc illustrated and show a significantly higher recovery for centrifugal cytology.4 Comment Considering the diagnostic accuracy as well as the simplicity and cost of centrifugal cytology, which in our institution is the same as other techniques, large scale screening, especially for high risk populations (smokers, chemical handlers, and patients with previous bladder tumors), should be considered feasible and a good supplement to cystoscopic evaluation. Department of Urology P.O. Box 016217 1475 N.W. 12th Avenue Miami, Florida 33101 (DR. LOCKHART)
Results Cell recovery rates comparing centrifugal cytology technique versus cytocentrifuge, using the ratio of the corrected mean cell counts of paired samples, is illustrated in Table I. The recovery was corrected both in terms of the number of cells applied to the two devices and the ratio of the area of the dispersions (14.4). The results show a marked superior recovery rate and ratio for centrifugal cytology especially with malignant cells. Recovery ratios for red blood cells (RBC), white blood cells (WBC),
UROLOGY
/ NOVEMBER 1986
/
VOLUME XXVIII,
mean cell counts
References 1. Leif RC, et al: Centrifugal cytology. IV. The preparation oi fixed stained dispersions of gynecological cells, Acta Cytol 19: 1% (1975). 2. Leif RC, Silverman MA, Bobbitt D, and Ng A: Centrifugal cytology: a new technique for cytodiagnosis, Lab Managemeni 17: 38 (1979). 3. watson P: A slide centrifuge: an apparatus for concentrating cells in suspensions onto a microscope slide, J Lab Clin Med 68: 494 (1966). 4. Leif RC: Leif Centrifugal Cytology Bucket: document num ber A 144624, FDA form 510K (1979).
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43:
M.D.
A. NG, M.D.
PH.D.
D. BOBBITT, J. LOCKHART,
M. SILVERMAN,
C.T.
V. A. POLITANO,
M.D.
M.D. M.D.
D. HINDMAN
From the Departments of Urology and Pathology, University of Miami, School of Medicine, Jackson Memorial Hospital, and the Papanicolaou Cancer Research Institute, Miami, Florida
ABSTRACT-A new technique, centrifugal cytology, appears to have a high recovery rate of malignant cells from voided urine specimens resulting in a high probability of early disease detection and should be considered a good supplement to cytoscopic evaluation of high-risk populations.
Exfoliated urine cytology has proved to be a useful tool in the diagnosis and management of bladder carcinoma. However, like all diagnostic screening procedures, its usefulness is proportional to the probability of disease detection versus its cost. Because of the low incidence of positive specimens and the relative high cost of preparing urine cytology, large scale screening has not been advocated. A new technique, centrifugal cytology, developed by Doctor Robert Leif and co-workers,’ appears to be simple, relatively inexpensive, and has a nearly quantitative recovery of cells on a glass slide with minimal cell overlap resulting in a high probability of early disease detection The major innovation with this new technique is a higher recovery of abnormal ceils in a smaller area resulting in a rapid and highly sensitive screening procedure. All other current cytology centrifugation techniques used to trap cells are often complex, tedious, and result in distortion of cells, making accurate evaluation by the pathologist difficult. The purpose of this article is to show that centrifugal cytology is more efficacious than other standard commonly used cytologic centrifugation techniques. 432
Material and Methods The centrifugal cytology technique can be performed on freshly voided specimens or specimens stored in a 10% transport medium* for stabilization. After preliminary routine centrifugation, the samples are resuspended in Mucolexx* solution. The Leif Centrifugal Cytology Bucket Rotor1 consists of a sample chamber and a carrier unit shown in parts 1 and 2 of Figure 1. The samples are placed in the sample chamber (parts 3 and 4). Centrifugation at 1,500 r-pm for ten minutes is then performed. Following this, a syringe with a 21-gauge needle is inserted in the small hole of the sample chamber and the supernatant removed (part 5). The fixative (4% glutaraldehyde solution) is then added to the sample chamber (part 6) and recentrifuged at 1,500 rpm for fifteen minutes. The slide is then removed from the bucket and stained, using Papanicolaou stain protocol.2 To prove the diagnostic accuracy of centrifugal cytology, two types of studies were performed. The first compared cell recovery rate of centrifugal cytology to the cytocentrifuge ‘Lerner Laboratories Division of Shandon Scientific, Pittsburgh, Pennsylvania. ICoulter Electronics, Inc., Hialeah, Florida.
UROLOGY I NOVEMBER 1986 / VOLUMEXXVIII, NUMBER5
FIGURE1. Technique for centrifugal cytology: (1 and 2) sample chamber and carrier units. (3 and 4) Placement of samples in sample chamber. (5) Ajt er centrijugation, 21-gauge needle is inserted in small hole OJ chamber Supernatent is removed. (6) FOUT per cent glutaraldehyde solution is added (‘GOT fixation) ana recentrijugation is peTjormed. TABLE I. Cell Type
WBC
Centrifugal cytology/ cytocentrifuge
126
Ratio of corrected
FtBC Transitional 60
Squamous
Columnar
Histiocytes
Abnormal
Malignanl
35
31
161
56
40
90
which is another common and popular centrifugation technique. 3 This was done using fourteen paired urine specimens, calculating total cell counts and ratios of recovered cells after the split samples were corrected for differences in volume. The results were then compared as to the type of cells recovered and a ratio calculated for each type of cell. The second part of the study was performed using 73 known positive bladder cancer patients and 14 cystoscopically known negative patients (post-treatment patients). Calculation of false positive and false negative rates was then performed. A comparison study with cytocentrifuge technique using known positive bladder cancer patients was also performed.
and normal and abnormal bladder cells are alsc illustrated and show a significantly higher recovery for centrifugal cytology.4 Comment Considering the diagnostic accuracy as well as the simplicity and cost of centrifugal cytology, which in our institution is the same as other techniques, large scale screening, especially for high risk populations (smokers, chemical handlers, and patients with previous bladder tumors), should be considered feasible and a good supplement to cystoscopic evaluation. Department of Urology P.O. Box 016217 1475 N.W. 12th Avenue Miami, Florida 33101 (DR. LOCKHART)
Results Cell recovery rates comparing centrifugal cytology technique versus cytocentrifuge, using the ratio of the corrected mean cell counts of paired samples, is illustrated in Table I. The recovery was corrected both in terms of the number of cells applied to the two devices and the ratio of the area of the dispersions (14.4). The results show a marked superior recovery rate and ratio for centrifugal cytology especially with malignant cells. Recovery ratios for red blood cells (RBC), white blood cells (WBC),
UROLOGY
/ NOVEMBER 1986
/
VOLUME XXVIII,
mean cell counts
References 1. Leif RC, et al: Centrifugal cytology. IV. The preparation oi fixed stained dispersions of gynecological cells, Acta Cytol 19: 1% (1975). 2. Leif RC, Silverman MA, Bobbitt D, and Ng A: Centrifugal cytology: a new technique for cytodiagnosis, Lab Managemeni 17: 38 (1979). 3. watson P: A slide centrifuge: an apparatus for concentrating cells in suspensions onto a microscope slide, J Lab Clin Med 68: 494 (1966). 4. Leif RC: Leif Centrifugal Cytology Bucket: document num ber A 144624, FDA form 510K (1979).
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