A 35-year-old man arrived at a hospital in Athens with a fever, a long history of painful urination, and a stop-start urine stream. His serum creatinine was 2 mg/dl, above the normal range for an adult man. His urea was elevated at 80 mg/dl. An ultrasound showed both ureters swollen with backed-up urine.
An X-ray explained why. His bladder held two stones, and the larger one measured 60 by 45 by 30 millimeters and weighed 310 grams, roughly 11 ounces. It occupied the bladder cavity and dammed urine back into both kidneys.
The case, published July 13 in the European Journal of Case Reports in Internal Medicine, is unusual on several counts at once. But the detail his doctors flagged as new is the reason the stone formed in the first place.
A Stone That Should Not Have Been There
Bladder stones account for only about 5 percent of urinary tract stones, and giant ones, defined as measuring more than 4 centimeters and weighing more than 100 grams, are rare anywhere.
In wealthy countries, they show up almost exclusively in older men. The reason is mechanical: an enlarged prostate, a narrowed urethra or a neurogenic bladder prevents complete emptying; urine sits, minerals precipitate, and a stone slowly builds. Benign prostate enlargement and urethral stricture are uncommon in a man in his thirties. Most patients also have a single stone, while multiple stones are described in up to 30 percent of cases.
This patient had none of the usual anatomical explanations. What he had was a history of intravenous opioid use.
Giant stones do get reported, but the pattern is consistent. A 2014 report from Tabriz, Iran described an 826-gram stone measuring 110 millimeters across in another 35-year-old man, and the authors flagged the absence of any obstruction or foreign body as the case's most unusual feature. A 2025 report of a two-pound stone described a 32-year-old man with urinary retention, blood in the urine, and painful urination. In both, the question of why the stone formed went largely unanswered.
How Opioids Keep the Bladder from Emptying
Opioids interfere with urination through several routes at once, and the effect is well documented even if the downstream consequence in this case is not.
The drugs carry anticholinergic properties that interrupt the micturition reflex and raise tone in the bladder sphincter, so the bladder does not fully empty. Morphine can also bind spinal receptors and cause the bladder muscle to relax outright. Animal work cited in the report points to mu and delta opioid receptors in the central nervous system as key players in the centrally mediated suppression of bladder motility.
The mechanism is the same one behind urinary retention from antidepressants, anticholinergics, alpha agonists, and antipsychotics. What changes with chronic opioid use is duration. Residual urine stays in the bladder day after day for years, and that stagnation is the condition stones need. Recreational drug use carries a broader set of urological complications that vary by substance.
The authors write that "Hidden predisposing factors such as chronic substance abuse may result in chronic urinary retention" and stone formation. They state that no case report published to date involved chronic substance abuse as the underlying pathology.
The Slow Damage Nobody Was Watching
Bladder stones grow quietly. Symptoms are chronic and vague, and they can be dismissed or endured for a long time before anyone investigates.
By the time this man reached the hospital, urine backflow had produced bilateral hydronephrosis, swelling of both kidneys, and measurable loss of kidney function. His urine culture grew Providencia stuartii at 100,000 colony-forming units per milliliter, and he had an ulcer on his left elbow. The authors note that severe kidney impairment from bladder stones is uncommon because the stones are usually not big enough to obstruct both sides.
Treatment came in two stages. He received piperacillin-tazobactam guided by the culture sensitivities, then went to open cystolithotomy under general anesthesia. Both stones came out with no complications. His creatinine fell progressively back to normal, and his urination normalized.
What This Case Changes for Younger Patients
The clinical lesson the authors draw is about the questions doctors ask. A young man with signs of urinary tract infection and unexplained kidney impairment is not an obvious candidate for imaging that looks for a stone this size.
They recommend that the initial workup for young men with urinary symptoms include plain X-ray and ultrasound, along with urinalysis, creatinine, calcium, uric acid, sodium and potassium. Where no anatomical cause turns up, they argue that a careful substance use history is essential rather than optional.
The evidence class here is worth stating plainly. This is a single patient. It cannot establish how often opioid use leads to bladder stones or quantify the risk to anyone else, and the connection between opioid related retention and this particular stone remains the treating team's interpretation. Anyone taking prescribed opioids who notices difficulty emptying the bladder, a weak or interrupted stream, or repeated urinary infections should raise it with a clinician rather than wait for the symptoms to resolve on their own.
Key Questions Answered
What counts as a giant bladder stone? A bladder stone measuring more than 40 millimeters across and weighing more than 100 grams. The larger stone removed in this case measured 60 by 45 by 30 millimeters and weighed 310 grams.
Why is the opioid link considered new? The authors report that no previously published case of giant bladder calculi identified chronic substance abuse as the underlying pathology. Opioid related urinary retention is well documented, but stone formation as a downstream consequence had not been described this way.
How do opioids cause urinary retention? They interrupt the reflex that triggers urination and increase tone in the bladder sphincter through anticholinergic effects. Morphine can also act on spinal receptors to relax the bladder muscle. The result is incomplete emptying and stagnant urine.
How did the stone damage his kidneys? It obstructed urine outflow, causing urine to back up into both kidneys. That produced bilateral hydronephrosis and reduced kidney function, reflected in a serum creatinine of 2 mg/dl on admission.
How was it treated? Antibiotics for the accompanying infection, followed by open cystolithotomy, a surgical opening of the bladder. Both stones were removed without complications, and his kidney function returned to normal afterward.
Does one case mean opioid users should be screened? It does not establish a general risk. This is a single patient report. The authors suggest taking a substance use history in young patients with bladder stones and no other explanation, which is a clinical recommendation rather than a screening policy.
