Biopsy of the Kidneys, Bladder, and Prostate

Renal biopsy

Indications for diagnostic biopsy include unexplained nephritic syndrome or nephrotic syndrome or acute kidney injury or concern for renal malignancy. Biopsy is occasionally done to assess response to treatment. Relative contraindications include bleeding diathesis and uncontrolled hypertension. Mild preoperative sedation with a benzodiazepine may be needed. Anticoagulants and antiplatelet agents should be withheld prior to the procedure.

Biopsies are performed with the patient lying face down on the examination table for biopsy of a native kidney or supine for biopsy of a transplanted kidney. The skin over the site is cleaned and anaesthetized. A biopsy needle is inserted through the skin into the kidney often under ultrasound or CT guidance and typically 2 to 3 samples are taken. After the biopsy, pressure is applied to the site to minimize bleeding. Complications are rare but may include renal bleeding requiring transfusion or radiologic or surgical intervention.

Bladder biopsy

Bladder biopsy is indicated to diagnose certain disorders (eg, bladder cancer, sometimes interstitial cystitis or schistosomiasis) and occasionally to assess response to treatment. Contraindications include bleeding diathesis and acute tuberculous cystitis. Preoperative antibiotics are necessary only if active urinary tract infection (UTI) is present. Anticoagulants and antiplatelet agents should be held prior to the procedure.

The biopsy instrument is inserted into the bladder through a cystoscope; rigid or flexible instruments can be used. Procedures with rigid cystoscopes that have better optics and larger channels allow for biopsy of larger tissue samples but need to be performed under regional or general anesthesia. Those with flexible cystoscopes are less invasive, can be done in the outpatient setting under local anesthesia, and are frequently used for initial diagnosis and ongoing monitoring. The biopsy site is cauterized to prevent bleeding. Based on the extent of the biopsy, a drainage catheter may be left in place to facilitate healing and drainage of clots. Complications include excessive bleeding, urinary retention, UTI, and bladder perforation.

Prostate biopsy

Prostate biopsy is usually done to diagnose prostate cancer. Contraindications include bleeding diathesis, acute prostatitis, and UTIs. Patient preparation includes stopping aspirin, antiplatelet medications, and anticoagulants appropriately before biopsy; preoperative antibiotics; and an enema to clear the rectum. With the patient in a lateral or lithotomy position, the prostate is located by palpation or, preferably, transrectal ultrasound in which an ultrasound probe inserted in the rectum provides images to help guide placement of the biopsy needle. The needle typically is inserted through the ultrasound probe or may, alternatively, be inserted through the perineum. Multiple samples (10 to 20) are usually taken. When available, a multiparametric MRI image can be digitally combined (fused) with the ultrasound image to better identify lesions that need to be biopsied. Multiparametric MRI results are scored according to the MRI PI-RADS system in which the malignant potential of a lesion is expressed on a scale of 1 (low risk) to 5 (highest risk) of identifying an aggressive cancer (. Patient preparation includes stopping aspirin, antiplatelet medications, and anticoagulants appropriately before biopsy; preoperative antibiotics; and an enema to clear the rectum. With the patient in a lateral or lithotomy position, the prostate is located by palpation or, preferably, transrectal ultrasound in which an ultrasound probe inserted in the rectum provides images to help guide placement of the biopsy needle. The needle typically is inserted through the ultrasound probe or may, alternatively, be inserted through the perineum. Multiple samples (10 to 20) are usually taken. When available, a multiparametric MRI image can be digitally combined (fused) with the ultrasound image to better identify lesions that need to be biopsied. Multiparametric MRI results are scored according to the MRI PI-RADS system in which the malignant potential of a lesion is expressed on a scale of 1 (low risk) to 5 (highest risk) of identifying an aggressive cancer (1, 2).

Overlying structures (perineum or rectum) are anesthetized, a spring-loaded biopsy needle is inserted into the prostate, and tissue cores are obtained. Complications include the following:

• Urosepsis

• Hemorrhage (including hematuria and rectal bleeding)

• Urinary retention

• Hematuria

• Hematospermia (often for 3 to 6 months after biopsy)

Urine cytology

Urine cytology is sometimes useful in diagnosing cancers of the kidneys and urinary tract. For individuals at high risk—for example, people who smoke, people who work with petrochemicals, and people with painless bleeding—urine cytology may be used to screen for cancer. For patients who have had a bladder or kidney tumor removed, the technique may be used for follow-up evaluation. The sensitivity of urine cytology varies with histologic grade of a tumor, but specificity is high, suggesting that a positive result is a reliable indicator of cancer in the urinary tract. Analysis for tumor markers increases the sensitivity of the test and can help in risk stratification and treatment planning (3).

References

1. 1. Barentsz JO, Richenberg J, Clements R, et al. ESUR prostate MR guidelines 2012. Eur Radiol. 2012;22(4):746-757. doi:10.1007/s00330-011-2377-y

2. 2. American College of Radiology® Committee on PI-RADS®. PI-RADS 2019 v2.1. Available at: https://www.acr.org/-/media/ACR/Files/RADS/PI-RADS/PIRADS-V2-1.pdf. American College of Radiology. Accessed on January 12, 2026.

3. 3. Sullivan PS, Chan JB, Levin MR, Rao J. Urine cytology and adjunct markers for detection and surveillance of bladder cancer. Am J Transl Res. 2010;2(4):412-440.