The accuracy of urinary cytology in daily practice

Abstract

Background: Most studies of urinary cytology have been research analyses designed to test the method itself, and many claim that the high diagnostic yields in these studies cannot be achieved in daily practice. The authors examined the clinical and pathologic records in three hospital pathology practice settings--academic, community, and cancer referral settings--to determine the diagnostic yield of urinary cytology under daily clinical conditions.

Methods: Records of consecutive urinary cytology specimens from 1672 patients reported from the years 1990-1994 were reviewed and correlated with histologic and clinical information. Initial analyses were based on the records themselves, without review of pathologic specimens. Subsequently, a subset of specimens was reviewed to determine reasons for noncorrelations.

Results: Results confirmed that the diagnostic sensitivity and specificity of urinary cytology for high grade transitional cell neoplasms, as reported in the daily practice of pathology, are very high (79% and >95%, respectively). Disaggregated cells from low grade transitional cell neoplasms usually lack recognizable features of neoplasia, and attempts to classify such lesions cytologically result in low diagnostic yield, with an overall sensitivity of 26%. Of these 1672 patients, 707 had insufficient clinical information for analysis, despite diligent and persistent efforts to acquire it.

Conclusions: The diagnostic yield of consultations based on urinary cytology in the daily practice of pathology is high, regardless of whether the practice setting is referral-based or community-based. The available information indicates that in approximately 79% of patients with high grade transitional cell neoplasms, the neoplasms can be detected using urinary cytology. Conversely, a negative result is predictive of no cancer in more than 90% of cases. Sensitivity for detecting low grade urothelial lesions is low; however, most of these are easily detected cystoscopically. The authors' inability to acquire sufficient information to determine diagnostic yield in a large percentage of their cases was disturbing to them. Not only did this deficiency render their analyses incomplete, but lack of easily accessible follow-up and the apparent low priority for quality assurance activities among pathologists in all types of practice settings is likely to significantly reduce the feedback required for pathologists to acquire and maintain expertise in this very difficult area.