Baseball-Sized Bladder Stone Found Inside Woman

A bladder stone the size of a baseball—and with growth rings inside it just like a tree trunk—was spotted inside a 72-year-old woman. The woman, who has been paralyzed from the chest down for 30 years, went to the hospital in China after she started peeing blood, according to a case report in the New England Journal of Medicine. The doctors suspected a bladder stone; however, upon investigating using ultrasound, found that the stone was an enormous oval, measuring about 2.4 inches by 3.1 inches by 3.5 inches. For comparison, the average baseball is about 2.9 inches across. "An abdominal ultrasound had identified a bladder stone," the doctors wrote in the case report. "Physical examination was notable for mild tenderness and a palpable mass." The woman was also discovered to have several bladder diverticula, which are small pockets or pouches in the bladder wall.

They develop when urine becomes concentrated, causing minerals like calcium oxalate and uric acid to crystallize and clump together, forming a ball of hard material inside the bladder. If the bladder doesn't fully empty, leftover urine can become concentrated, promoting stone formation. This can also happen if urine is caught in bladder diverticula. Additionally, catheters can act as a base for stones to form, and repeated urinary tract infections (UTIs) can lead to the formation of struvite bladder stones. Due to this patient's paraplegia, she did not have total control of her bladder, meaning that she had a long-term catheter in her urethra that allowed her to pee. These circumstances and her bladder diverticula are all risk factors for bladder stones, the doctors explained. The woman's urine was also found to contain high levels of white blood cells or pus, blood and nitrites, indicating the presence of a urinary tract infection (UTI), as well as E. coli and Morganella morganii bacteria. Computed tomography of the stone revealed that it was layered, and appeared to have rings like the inside of a tree trunk. "Some bladder stones form tree ring–like layers owing to episodic variations in mineral deposition and urine composition over time," the doctors wrote. The doctors first treated the woman's UTI using antibiotics, before using a laser to break down the stone. With such a treatment, the small fragments can either pass naturally through the urine or be removed with special tools during the procedure. "At 1 month of follow-up, the patient's symptoms had resolved," the doctors said. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about bladder stones? Let us know via science@newsweek.com.

Reference

Li, Z., & Li, Z. (2025). Bladder Stone. New England Journal of Medicine, 392(2). https://doi.org/10.1056/nejmicm2411456