Improving the Predictability of Indeterminate Results of Urinary Cytologic Samples: An Outcomes and Cytomorphologic Study
Christopher J VandenBussche, Srividya Sathiyamoorthy, Hui Guan, Dorothy Rosenthal. The Johns Hopkins Hospital, Baltimore, MD
Background: In most cytopathology laboratories, urinary tract (UT) samples are second only to Pap tests in annual volume. We previously designed a template in order to standardize our UT diagnostic categories to enable our clinicians to uniformly manage their patients. We have also examined the common cytomorphological features found in the category “atypical urothelial cells, suspicious for high grade urinary carcinoma (AUC-H)” that proved most predictive of high-grade urothelial carcinoma (HGUC). These features are utilized in the current study, a training exercise, in an attempt to improve the predictive value of this clinically frustrating category.
Design: The hospital laboratory information system was searched for cytology specimens that were diagnosed as “Atypical urothelial cells of undetermined significance” (AUC-US) from July 1, 2007 to June 30, 2009. 160 specimens from 118 patients were identified and classified by clinical indication (surveillance for neoplasia or hematuria). 123 specimens with subsequent biopsy or longitudinal follow-up were selected for preliminary review. A junior and senior pathologist, blinded to outcome, separately evaluated each of the AUC-US specimens for individual cytologic criteria found to be most predictive of HGUC in specimens diagnosed as AUC-H. The predictions were then matched with the follow-up biopsy or clinical outcomes, which were tracked over the 18 months following the July 2009 cutoff for inclusion in the study.
Results: For surveillance patients (n = 67), 48% had benign follow-up, 17% had LGUC, and 30% had HGUC. The sensitivity and specificity of the criteria in these patients were 86% and 59%. For patients with hematuria (n = 56), 11% were diagnosed with nephrolithiasis, and 10% were diagnosed with HGUC; the remainder of the samples were considered benign. In this patient group, the sensitivity and specificity of the criteria (57% and 41%) were both poor.
Conclusions: Patients with urine specimens classified as AUC-US at our institution are less likely to be subsequently diagnosed with HGUC. We have defined cytologic criteria which predict the risk of HGUC on follow-up with a high sensitivity (86%) and acceptable specificity (59%) in surveillance patients. These criteria from our “training set” will be further refined following the examination of our remaining AUCUS specimens, which will serve as our “test set”. Reclassifying specimens meeting these criteria into a category with a higher level of suspicion for HGUC (ASC-H) may help guide clinicians to provide more appropriate follow-up to these patients.
Tuesday, March 20, 2012 9:30 AM
Poster Session III # 76, Tuesday Morning