Teaching Case

A 78-year-old man presented for an elective computed tomography (CT) of his abdomen and pelvis to investigate a progressively enlarging intraabdominal mass over a 15-year period. He had no significant past medical history. Examination elicited a protrusion in the epigastric region with an apparent umbilical hernia. Laboratory workup revealed deranged renal function. No prior imaging was performed over the 15 years.

A contrast-enhanced CT scan of the abdomen and pelvis revealed a grossly distended bladder measuring 21.3cm x 26.8cm x 30.2cm. The upper part of the bladder wall was trabeculated, suggestive of bladder outflow obstruction with corresponding bilateral hydronephrosis. The para-aortic and left iliac lymph nodes were enlarged, measuring 2.1cm and 3.2cm, respectively.

Magnetic resonance imaging (MRI) of the abdomen showed an enlarged prostate measuring 5.9cm x 6cm x 6.3cm with a volume of 122ml. A low signal intensity focus was visualised within the left transitional zone extending to the apex of the peripheral gland with restricted diffusion. Breach of the capsule and extension into the adjacent levator ani was seen. As seen in the CT scan, the MRI scan also showed extensive pelvic and para-aortic lymphadenopathy associated with bilateral hydroureteronephrosis.

Following the CT scan, our patient was admitted under the urology team who inserted a urinary catheter into the patient’s bladder, which drained 16000 ml of urine. Retrospective review of blood tests showed a prostate-specific antigen (PSA) of 407 µg/litre (normal range <4 µg/l).

Chronically distended bladder is an uncommon presentation with many causes, including diabetes, benign prostatic hyperplasia, neurogenic disease and malignancy. The largest reported volume in literature to date has been 11000 ml [1].

Typically, patients present with non-specific urinary tract symptoms. Our patient disclosed passing small amounts of urine daily with overnight dribbling and worsening abdominal distention. Unfortunately, our patient was diagnosed with locally advanced prostatic carcinoma.

In 2018, prostate carcinoma accounted for the second most frequent cancer in men globally, with more than a million new diagnoses and leading to 358,989 deaths [2].

Prostate cancer in early stages is often asymptomatic and advances slowly. Common issues include difficulty passing urine, nocturia and increased urinary frequency. However, progressive abdominal distention due to enlarged bladder is an extremely rare presentation.

Treatment of giant urinary bladder includes decompression of the urinary bladder by catheter insertion and treating the underlying cause. Following this, any compressive symptoms normally resolve with extended bladder drainage.

Our patient has been managed conservatively with androgen deprivation therapy and a long-term urinary catheter. His PSA level has dropped to 1.07 µg/l, and he no longer has any lower urinary tract symptoms.

Learning points

• Giant urinary bladder is a rare progressive condition with non-specific presentation, such as gradual abdominal distension and difficulty passing urine.
• Management of giant urinary bladder includes urinary catheterisation and treatment of the underlying cause.

Written informed patient consent for publication has been obtained.