Urinalysis Case Study - Urothelial Cells
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What are urothelial cells?
Urothelial cells – also termed “transitional epithelial” cells or “urothelial” cells – line portions of the urinary tract from the renal pelvis to the bladder in females, and the renal pelvis to the upper urethra in males. Urothelial cell morphology is dependent upon its position in the cell layers: the cells making up the base (basal) layer are cuboidal; the middle, proliferative layer is comprised of polyhedral (many-sided) cells and the inside surface of the bladder is formed by large “umbrella” cells that appear domed when the bladder is relaxed, but can stretch to accommodate the bladder filling.
Few urothelial cells are a normal finding in urine, but may be increased following urine catheterization or cystoscopy. When urothelial cells are present in clusters or contain large, irregular nuclei, it may be an indication of the presence of a urothelial carcinoma. In this case, cytology testing is recommended.
Morphology/Features:
- 20-30 µL
- Round, polyhedral or caudate appearance
- Finely granular
- Round or oval nuclei with distinct borders
Resources:
Color Atlas of the Urinary Sediment, College of American Pathologists, Northfield, IL.
Atlas of Urinary Sediment, Sysmex Corporation, Kobe, Japan.
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