Tuesday, May 16, 2006

Nephrology Cases #10: Cancer and Kidney Failure

A 65 year old man with previously normal renal function has a few days of poor appetite and is found to have a creatinine of 4 and widespread lymphadenopathy suspicious for lymphoma or leukemia. A urinalysis shows no proteinuria or hematuria. His renal function worsens despite intravenous fluids. What are the top four possible causes of his kidney failure? (Answers in comments.)

7 comments:

Unknown said...

1. Acute tubular necrosis due to decreased intake.
2. Urinary tract obstruction due to retroperitoneal lymphadenopathy.
3. Lymphomatous infiltration of the kidneys.
4. Spontaneous tumor lysis syndrome and uric acid nephropathy.

The Medicine Man said...

Does spontaneous tumor lysis syndrome really belong in the top four?

John

Unknown said...

I think so, particularly because this case actually turned out to be spontaneous tumor lysis syndrome. His uric acid was 20, and he responded well to rasburicase.

(I'm open to other suggestions for the top four.)

The Medicine Man said...

OK, I'll take your word for it. The cases of tumor lysis syndrome I've seen have occurred in leukemias and lymphomas after chemo was started.

I just thought that spontaneous TLS was rare.

John

Unknown said...

That's very fair. I'll add that there wasn't any hematuria or proteinuria, which reduces the likelihood of other causes, like bilateral renal vein thrombosis and minimal change disease with acute renal failure. Thanks.

Anonymous said...

Since the negative proteinuria is determined by U/A, not quantitative protein assessment why no cast nephropathy from myeloma? Patient was elderly.

Unknown said...

Joel,

Radiographically, the presentation seemed more consistent with lymphoma/leukemia than myeloma, as plasmacytomas tend to be more solitary, but anything is possible...