Case Study - May 2011

A 72 year old man presents with acute renal failure and uraemic symptoms. His creatinine on admission is 790 micromol/litre and his potassium is 7.6. He has a past history of prostatic carcinoma for which he had external beam radiotherapy and is currently on a LHRH analogue with a stable PSA of 1.89ng/ml. He is haemodynamically stable and his examination reveals no abnormality. He goes on to have a CT KUB (and subsequent nephrostogram).
- What do these images show?
- What should his immediate management be?
- What should we do next?
- What are the possible causes of the appearances in the CT?
Reveal Answer
Open answer There is no fixed answer to this question, however your response should be similar to the one below:
- There is an obstructed left kidney due to a 3cm mass outside the renal pelvis/PUJ and an atrophic/shrunken right kidney. The nephrostogram looks like PUJ obstruction with multiple filling defects in the renal pelvis (which turn out to be blood clots).
- He needs urgent resuscitation according to ALS protocols. His immediate management (after ABC) should include an ECG looking for tented T waves. He should be put in a high care environment such as A+E Resus, HDU or ITU with cardiac monitoring. 10% Calcium gluconate 10mls should be administered via a large bore cannula and an actrapid infusion given. Having decompressed his system with a nephrostomy, the electrolytes should then be checked in 2 hours and discussed with the renal team as appropriate with view to dialysis if potassium remains high.
- Ideally discussed in a MDT setting. The mass could be biopsied percutaneously (as was done in this scenario) or an open biopsy could be performed. Para-aortic lymph nodes could be testicular in origin so one should send testicular tumour markers and undertake an USS scrotum if any doubt (normal in this case). The ultimate treatment may include surgical excision, radiotherapy or chemotherapy depending on the primary cause.
- Cancer – Lymphoma, testicular, intra-abdominal malignancy. Infection – TB, HIV. Inflammatory – para-aortitis (eg Abdominal Aortic Aneurysm). Sarcoid.
This gentleman’s histology was actually small cell neuroendrocrine carcinoma of uncertain origin.