Prostatic Urethral Calculus

32 year old male with sudden dysuria • Xray of the Week

Figure 1. A. Axial, B. Sagittal, C. Coronal CT abdomen-pelvis. What is the abnormality?

Figure 2. A. Axial, B. Sagittal, C. Coronal CT abdomen-pelvis showing large calculus in the prostatic urethra (red arrows).

Discussion:

Prostatic urethra calculi are uncommon accounting for less than 1% of all urinary stone disease. Usually seen in males over 50 years of age, the most common site of urethral calculi is the posterior urethra; however, calculi can be seen along the entire length of the urethra [1, 2]. Primary urethral calculi originate within the urethra and are usually the result of urinary stagnation and infection in poorly draining intra-urethral and paraurethral cavities such as abscesses, diverticula, and mucosal ulcerations [1, 2]. Urethral strictures may also lead to stagnation and primary urethral calculi formation [1]. Secondary calculi are those that originate in the upper urinary tract or bladder and are much more common than primary urethral calculi. While primary urethral calculi are often asymptomatic, secondary calculi often produce sudden obstruction resulting in dysuria, hematuria, or incontinence [1-3].

Urethral calculi may be seen as an incidental finding on radiographs or CT scan. They may also be visualized on transabdominal or transrectal ultrasound. Retrograde urethrogram can be utilized to define the anatomy when a urethral stricture or diverticulum is suspected [2]. In this case, CT scan was performed due to the patient’s symptoms and it revealed the large calculus in the prostatic urethra (Figs. 1,2).

Treatment is dependent upon the size, shape, and location of the calculus and by the status of the urethra. Smaller calculi can often be treated with transurethral endoscopic techniques including laser and pneumatic lithotripsy. If the stone is large and immobile, it may require open surgery via a perineal or a suprapubic approach [1].

References:

1. Demir, O., et al., The giant calculus within the prostatic urethra. Urol Res, 2011. 39(4): p. 319-21 DOI: 10.1007/s00240-010-0350-x. Retrieved from https://link.springer.com/article/10.1007%2Fs00240-010-0350-x

2. Friedman, P.S., L. Solis-Cohen, and S.M. Joffe, Urethral Calculus: Its Roentgen Evaluation. Radiology, 1954. 62(2): p. 248-250 DOI: 10.1148/62.2.248. Retrieved from https://pubs.rsna.org/doi/abs/10.1148/62.2.248

3. Kamal, B.A., et al., Urethral calculi: presentation and management. BJU Int, 2004. 93 PubMed: https://pubmed.ncbi.nlm.nih.gov/15008727/ doi:10.1111/j.1464-410x.2003.04660.x

Shama Jaswal is an International Medical Graduate, currently doing research at Mallinckrodt Institute of Radiology (MIR), Saint Louis. She aims at pursuing Diagnostic Radiology residency and poses a keen interest in research alongside academics. At MIR, she has been fortunate to work on various oncology projects including the project in which they studied how the difference in fat metabolism in both sexes can affect the cancer survival and outcome, and how this study can further improve prognosis through treatment modification. Shama is both an accomplished sprinter and singer having won several national competitions in in each discipline in India. She also has a strong passion for cooking and gardening.

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Kevin M. Rice, MD is the president of Global Radiology CME

Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.

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