of Week Home
1 March 2012 - Case of the Week #235
All cases are archived on our website. To view them sorted by number, diagnosis or category, visit our Home Page and click on the Case of the Week button on the left hand side. To subscribe or unsubscribe to the Case of the Week or our other email lists, click here.
Thanks to Dr. Saroona Haroon, The Aga Khan University Hospital (Pakistan), for contributing this case. To contribute a Case of the Week, follow the guidelines on our Case of the Week page.
(1) We have a Special offer thru 4/30/2012 for our Jobs page. Post a Pathologist/PhD Job ad for the regular price of $800, and receive one FREE posting for a Job-Other ad (normally $500), if sent to us within 2 business days.
(2) We have added links for free CME from Cleveland Clinic to our CME page, which has a link on the left side of the Home page.
(3) The second half of the Lymphoma and plasma cell neoplasms chapter (T/NK cell disorders, Hodgkin's lymphoma, post-transplant, other) was recently updated based on a review by Dragos C. Luca, M.D., Children's Hospitals & Clinics of Minnesota. The balance of this chapter was updated in early 2011.
Case of the Week #235
A 52 year old Asian man, hypertensive for 7 years, presented with slowly increasing serum creatinine levels, currently 3.1 mg/dl, and current renal failure. Urine showed microscopic hematuria. His past medical history included a heart valve replacement due to valvular heart disease at age 30 years. As the etiology of the increasing creatinine was unknown, a renal biopsy was obtained.
What is your diagnosis?
Renal hemosiderosis, secondary to hemolytic anemia (heart valve complication)
The diagnosis was confirmed by an iron stain:
Renal hemosiderosis due to hemolytic anemia is a rare cause of renal failure (Am J Pathol 1966;48:409, Indian J Pathol Microbiol 2011;54:379). Hemosiderosis is defined as the histologic equivalent of secondary iron overload, usually due to hemosiderin, which may be focal. Hemosiderin is a golden yellow to brown granular cellular pigment due to hemoglobin breakdown. Typically, free serum hemoglobin is bound to haptoglobin, but in severe cases, the free hemoglobin is filtered by the kidney and deposited in the proximal convoluted tubules, which may cause renal failure.
Renal hemosiderosis is caused by recurrent intravascular hemolysis, and may be due to hemolytic anemia, paroxysmal nocturnal hemoglobinuria (PNH) and mechanical hemolysis from prosthetic cardiac valves. In this case, the hemolysis was attribute to chronic mechanical damage due to shearing of red blood cells by the prosthetic valve. Correction of a dysfunctional valve may be therapeutic (Arch Mal Coeur Vaiss 1993;86:111).
Nat Pernick, M.D., President
and Liz Parker, B.A., Associate Medical Editor
30100 Telegraph Road, Suite 408
Bingham Farms, Michigan (USA) 48025
Alternate email: NatPernick@gmail.com