Alcoholic carbowax prefixation and formal alcohol fixation : A new technique for urine cytology

To compare the cellular yield and sensitivity of cancer detection by urine cytology using alcoholic carbowax as a prefixative and formal alcohol as a final fixative with the conventional centrifugation-and-smearing method. Four hundred seventeen voided urine specimens were examined. Each specimen was divided into two equal portions. One portion was centrifuged and wet fixed (CS). The other was treated with alcoholic carbowax as a prefixative and then fixed in formal alcohol (CW). The smears were studied for cellular yield, morphology, cancer detection rate and typing. The CW method yielded significantly more cells with excellent morphology. It detected 25 more abnormal cases out of a total of 86, including 5 more transitional cell carcinomas, as compared to the CS method. This finding was statistically significant (P < .0000003). The CW method is simple and enhances cellular yield and the cancer detection rate as compared to the conventional centrifuge-and-smear technique.