Urinary bladder calculus
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Synopsis
Bladder calculi, or cystoliths, once a common cause of urologic pathology, have become increasingly rare in the United States over the last few decades. This condition is distinct from nephrolithiasis or kidney stones, which are now much more common than bladder calculi.The decreased incidence of bladder calculi is largely because the 2 conditions principally associated with bladder stones, urinary stasis (most commonly due to benign prostatic hyperplasia [BPH]) and urinary tract infections (UTIs), are now more easily and frequently treated. BPH, once only effectively treated with surgery, is now frequently effectively and more easily treated with a combination of alpha blockers, 5-alpha reductase inhibitors, or transurethral resection. Consequently, the number of men suffering from chronic urinary retention has significantly decreased. Urinary stasis in the setting of neurogenic bladder is also a common etiology of bladder stone formation.
When urine is chronically retained in the bladder, any nidus, such as a small fragment of a stone passed from the ureter or a foreign body such as a ureteral stent or Foley catheter, can serve as a site for the precipitation and deposition of uric acid. In most retrospective studies of bladder stone composition, nearly all stones (as many as 80%) are entirely composed of uric acid, and most of the remainder contain a substantial portion of uric acid. Interestingly, neither gout or hyperuricemia appear to be contributory factors in the formation of bladder calculi. This is qualitatively different than nephrolithiasis, which in the United States is primarily due to calcium oxalate or calcium phosphate stones.
Infrequently, stones may be formed from calcium oxalate, calcium phosphate, ammonium urate, cystine, or struvite (calcium-ammonium-magnesium phosphate or "triple phosphate"). Stones composed of struvite are almost always associated with chronic UTI and colonization with Proteus. An additional provoking factor in bladder stone formation is thought to be any condition that causes urothelial inflammation such as UTI and bacteriuria or urothelial dysplasia.
Demographically, patients with bladder stones are most frequently men over the age of 45, although patients with neurogenic bladder frequently develop stones at any age.
Bladder stones, particularly large and nonobstructive stones, do not frequently cause symptoms. Larger stones are thought to be less able to move significantly within the bladder and cause injury to the bladder wall and seem to be less prone to lodge in the bladder infundibulum / neck and cause acute obstruction. When patients do present with symptoms, they may be nonspecific and include suprapubic discomfort, hematuria, dysuria, urinary frequency, urinary hesitancy or poor urine stream, penile pain in male patients, or cloudy urine.
Codes
ICD10CM:N21.0 – Calculus in bladder
SNOMEDCT:
70650003 – Urinary bladder stone
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
Intravesicular filling defect on imaging:- Blood clot – On CT, stones will typically have a much higher Hounsfield Unit (HU) value ( > 100 HU) while blood clot is typically 50-75 HU.
- Urothelial cell tumor (see urothelial carcinoma) – While a pedunculated tumor (on a stalk) may exhibit some motion with patient repositioning, the tumor will not be as freely mobile as would be a stone on ultrasound. Similarly, a tumor will present with a lower radiographic attenuation on CT than a bladder stone.
- Fungal ball – Presents with comparatively low HU value on CT.
- Loin pain-hematuria syndrome
- Ectopic pregnancy – Beta human chorionic gonadotropin (beta-hCG) should be checked in any woman who has a possibility of pregnancy.
- Testicular tumors (see testicular cancer)
- Ovarian torsion or rupture
- Mesenteric ischemia – Hematuria is not a feature of this disease.
- Herpes zoster – Overlying skin changes will be apparent. Pain is typically burning in quality, constant, and remains in a dermatomal distribution.
Best Tests
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Management Pearls
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Therapy
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Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.Subscription Required
References
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Last Reviewed:08/16/2018
Last Updated:08/15/2019
Last Updated:08/15/2019
Patient Information for Urinary bladder calculus Overview
Urinary bladder calculus is a condition in which a mineralized mass, or bladder stone, develops in your bladder. The bladder is the organ where urine collects prior to urination. These stones generally appear when your bladder is not able to completely empty after urination, causing the formation of crystals. This can happen with certain underlying conditions like spinal cord injury, enlarged prostate, urinary infection, or a bladder defect. Bladder stones can also occur at the site of an indwelling urinary catheter, after pelvic radiation treatment, or from small kidney stones entering the urinary bladder.Some bladder stones pass on their own while others are too large and require treatment from a medical professional.
Who’s At Risk
95% of bladder stones occur in men. Other risk factors for bladder stones include:- Enlarged prostate or other bladder obstruction
- Damaged nerves to the bladder (stroke, spinal cord injury)
In developing countries, children are at risk due to:
- Dehydration
- Infection
- Diet deficient in protein
Signs & Symptoms
The symptoms of urinary bladder calculus are:- Pain in the lower abdomen
- Pain or feeling of discomfort in the penis
- Painful urination
- Disrupted urination (difficulty starting, poor urine stream, incomplete urination)
- Bloody or dark-colored urine
Self-Care Guidelines
If you have an enlarged prostate, getting this treated will reduce your chance of developing urinary bladder calculus.Drinking more water can help dilute mineral concentration and prevent the development of bladder stones.
When to Seek Medical Care
Contact your health care provider when you have symptoms of a bladder stone.Treatments
- Bladder stones need to be removed to prevent the complete obstruction of urine outflow, which can make you very sick. If the stone is small, your health care provider may recommend drinking a lot of fluid to help the stone pass on its own.
- Certain medications may dissolve the stone.
- If the stone is large, a procedure called cystolitholapaxy may be recommended. A tube is inserted through your urethra so that the stone can be broken into smaller pieces using ultrasound, laser, or another mechanism.
- If the stone is too large for this procedure, your health care provider may have to surgically remove the stone by minimally invasive means (endoscope) or by making an incision in your bladder (open surgery).
Urinary bladder calculus