An evaluation of automated flow cytometry (FCM) in detection of carcinoma in situ of the urinary bladder.

Among a series of more than 500 urologic patients studied by automated flow cytometry (FCM), there were 123 who proved to have carcinoma in situ of the urinary bladder. Eighty had flat carcinoma in situ and 43 had papilloma with foci of carcinoma in situ or diffuse noninvasive papillary carcinoma. Of those with papillary carcinomas and papilloma with carcinoma in situ, 88% were positive by FCM, as were 98% of the cases of flat carcinoma in situ. The overall false negative rate was 6%. A statistically significant (P less than 0.02) difference in the proportion of cases with aneuploidy was found in papillary CIS (42%) compared with flat CIS (86%). The presence of aneuploidy (cell populations with DNA content other than normal diploid (2c) or tetraploid amount (3.9c-4.1c) as opposed to tetraploidy is thought to imply a more aggressive, less well differentiated tumor.