Diagnostic dilemma: A man's bladder looked like a Christmas tree

The patient: A 30-year-old man in Nigeria

The symptoms: The man went to the urology unit of a hospital after urine had been leaking out of small holes in his perineum — the skin between the penis and anus — for about two weeks. This condition is known as "watering can" perineum. The man had a history of various urinary problems, such as a poor stream, discharge from the urethra, urine dribbling, and a burning sensation while peeing.

What happened next: Because the man had a poor urinary stream — meaning his urine didn't flow as quickly or forcefully as usual — the doctors had to drain his full bladder before they could explore the cause of the leakage in his perineum.

The doctors attempted to insert a catheter through the urethra and into the bladder, creating a tunnel for urine to flow into a bag. However, as they tried to push the tube, they hit a wall. Something was blocking the catheter's path.

The doctors instead made an incision in his abdomen and inserted a catheter into the bladder that way, bypassing the urethra altogether. Once urine began to flow, they tested it for signs of infection and found Staphylococcus aureus bacteria. These bugs are an uncommon cause of urinary tract infections and usually appear only when there is a physical abnormality blocking urine flow, which allows this species to remain in the bladder and thrive.

The doctors referred the patient to the radiology department to get scans of his bladder and search for signs of such physical abnormalities. To visualize the bladder in X-ray scans, the radiologists administered an X-ray-sensitive dye through the abdominal catheter. This revealed that the bladder had inflated at its base, leaving a pointy tip.

The diagnosis: This condition is known as a "Christmas tree" or "pinecone" bladder, owing to its appearance.

The X-rays confirmed that urine had been blocked from leaving the organ. Yet a closer inspection of the bladder revealed no issues with the organ itself, such as an obstructing mass or bladder stones. This led the doctors to wonder if an obstruction was located elsewhere.

Further X-ray imaging revealed that the urethra had narrowed significantly about halfway up its length, cutting off urine flow. This condition is called a urethral stricture and has a multitude of causes.

Often, it arises following a pelvic injury or physical trauma, such as from falling onto a bicycle's crossbar. It can also stem from sexually transmitted bacterial infections or appear if a tumor presses against the tube. Sometimes, the condition has no identifiable cause. (The exact reason for this man's condition wasn't noted in the report of his case.)

The treatment: The doctors treated the man's staph infection with antibiotics and performed an operation to restore the urethra's channel. Surgery can offer some respite from the condition, but urethral strictures often reoccur, the doctors noted in the report.

What makes the case unique: A urethral stricture is an unusual cause of Christmas tree bladder. Normally, a bottleneck in the urethra slows urine flow, leading to some degree of distension in the bladder, but not so much that the organ would widen at the base into a tree-like shape.

The "Christmas tree" swelling is usually caused by a problem with the nerves that control bladder contractions, thus preventing it from emptying properly. Often, this occurs following nerve damage from a spinal cord injury, stroke or neurodegenerative disease, such as multiple sclerosis. Alternatively, it can arise if the neck of the bladder becomes constricted or choked, such as by an inflamed prostate in men.