Urine cytology case: high‑grade urothelial features
A shared cytology case showed classic high-grade urothelial carcinoma morphology in voided urine—marked nuclear hyperchromasia and high N/C ratio—highlighting key diagnostic hallmarks for hematuria workups. The slide post is a practical refresher for urinary cytology pattern recognition. (x.com)
The Paris System requires objective thresholds to call high‑grade urothelial carcinoma on cytology: at least 5–10 abnormal cells (10 cells for upper‑tract specimens), a high N/C cutoff (~≥0.7), irregular nuclear membranes, moderate hyperchromasia, and coarse/clumped chromatin. (acsjournals.onlinelibrary.wiley.com) Voided specimens show markedly variable cellularity; published adequacy guidance recommends ~30 mL and collection after several hours without voiding to improve yield, while Cytospin‑prepared voided urines have lower cellularity and sensitivity compared with instrumented bladder washings. (pathologyoutlines.com) Reported diagnostic performance for urine cytology in detecting high‑grade disease varies widely—sensitivity in the literature ranges from roughly the mid‑30s percent up to ~79% depending on specimen type and criteria, while specificity is consistently high (≈95–99%) across series. (pathologyoutlines.com) When morphology raises concern but clinical context is equivocal, reflex molecular/ancillary testing is commonly used: UroVysion FISH (probes for chromosomes 3, 7, 17 and 9p21) increases sensitivity versus cytology alone and is recommended to adjudicate atypical cases in some centers. (oncology.testcatalog.org) A cytology call suspicious or positive for high‑grade urothelial carcinoma on a voided urine specimen typically prompts expedited urologic workup including cystoscopy and, when indicated by risk factors, CT urography or upper‑tract evaluation per contemporary hematuria guidelines. (auanet.org)
