Significance of tissue fragments in voided urine specimens

OBJECTIVE: To determine the diagnostic significance of STUDY DESIGN: We reviewed all the voided urine specimens collected and proc essed by the Millipore (R) filter technique (Bedford, Massachusetts, U.S.A. ) at our institution between January 1, 1997, and December 31, 1998, and th e corresponding biopsies obtained within 120 days after urine examination. The type and number of tissue fragments were correlated with the histologic diagnosis and clinical features; the results were compared to those from a recently published study. RESULTS: Of the 2,553 voided urine specimens examined, 174 (7%) had corresp onding biopsies. Cell groups (tissue fragments) consisting of either flat s heets or three-dimensional structures were significantly move common (57%) (chi (2) P < .005) in urine specimens with biopsies revealing urothelial ma lignancies than in negative biopsies (6%). Three-dimensional groups were al so statistically move common in cases with invasive transitional cell carci noma. Proper identification of tissue fragments teas highly significant and correlated with urothelial neoplastic changes. CONCLUSION: The results of the present investigation using the Millipore<(R )> filter technique for voided urine cytology processing, differed from tho se of a recently published study that employed cytocentrifugation. Tissue f ragments, to be differentiated from groups, clumps or clusters that often r esult from centrifugation and other concentration artifacts, were strongly associated with urothelial neoplasia, uncommonly with nonneoplastic disease processes affecting the urinary tract but always with urothelial disease.