Case Study - July 2008

The is a pelvic CT of a 66-year-old man with urinary sepsis whilst undergoing chemotherapy for bowel cancer. He had a low anterior resection and is know to have a pre-sacral collection discharging into the rectum. His chemotherapy has been put “on hold” pending treatment of this abnormality.
- What is the differential diagnosis?
- What investigation is now most appropriate?
- What issues decide the best treatment and its timing?
Reveal Answer
Open answer There is no fixed answer to this question, however your response should be similar to the one below:
There is crescentic calcification on the right side of the bladder, lying in a dependent position.
- The differential diagnosis includes a bladder calculus, a contrast leak from the abscess-related fistula or calcification on a catheter remnant
- Ultrasound may confirm the presence of a foreign body in the bladder (see below) but cystoscopy would be diagnostic
- The prime consideration is the need to start chemotherapy but the size of the calculus will also determine whether it should be removed endoscopically or by open surgery
Cystoscopy confirmed a bladder stone. The calculus had formed on the remnant of a catheter balloon, presumably left during the patient's earlier treatment.