Specimen collection for Cytology of urine

Specimen collection technique:

  • Voided urine
  • Ileal conduit urine
  • Catheter urine
  • Bladder washing
  • Upper urinary tract brush cytology

Voided urine

  • It is the most common sample type
  • Voided urine undergoes degeneration very quickly hence preservative are used to reduce cellular degeneration and stopping bacterial growth.
  • Voided urine should be obtained 3 to 4 hours after the patient has last urinated.
  • First morning voided urine specimens should be avoided because stagnant cells in the low acid-base balance (pH) and hypertonic environment undergo degenerative changes, making cytologic assessment difficult.
  • The minimum amount of urine necessary to ensure adequate cellularity is unknown, but it may be as high as 25 to 100 mL.
  • In women, voided urine can be contaminated by vaginal cells, so to ensure the adequacy of the sample, a midstream (“clean catch”) specimen is recommended.

Ileal conduit urine

• This specimen type is useful for follow up of patient who have been treated for bladder cancer.
• An ileal conduit is a urinary diversion that is constructed from a section of ileum when a patient has had their bladder removed during surgery for bladder cancer.
•These patients’ urine samples include a wide range of appearances, including a considerable number of degenerating interstitial epithelial cells, macrophages, inflammatory cells, and mucus..

Catheter urine

  • A urinary catheter is short plastic tubing that is inserted into the bladder to allow urine to drain freely into a bag.
  • Catheterization carries a risk of urinary tract infection
  • Urine from an indwelling catheter is often a pooled sample that has been at room temperature for many hours, and cellular degeneration can be noticeable.

Bladder washing

  • Bladder washing is not a common source of urine sample as the procedure is invasive.
  • It involves injecting 50-100 ml of saline through a catheter and aspirating fluid before collection.
  • The benefits of bladder washings over voided urine include higher cellular preservation, greater cellularity, and a lower risk of background particle contamination.

Upper urinary tract brush cytology

  • Direct washings, brushings, or biopsies of a ureter or renal pelvis lesion should be done when an upper urinary tract malignancy is suspected.
  • A fine brush is passed into the ureter under endoscopy and X-ray guidance. The brush is pushed back and forth to dislodge the cell after it has been passed into the suspicious area.
  • These cells adhere to bristle of brush and can be spread onto a slide.

Leave a Comment