4.1.4 Myoglobinuric/hemoglobinuric ATN

Definition: Acute renal failure due to hemoglobinuria and /or myoglobinuria.

In addition to the features described under “Hemodynamic ATN”, brownish casts best seen in the HE stained sections are present in distal tubules and collecting ducts. The nephron segments proximal to the casts often show prominent dilatation. Specific antibodies against hemoglobin or myoglobin can identify the chemical nature of the brownish material. The pigmented casts often contain also Tamm-Horsfall protein.  Very few brownish casts may also be present in other forms of ATN, but in hemoglobinuric or myoglobinuric ATN the casts are often massive and compact. This type of ATN may be found in myolysis e.g.severe trauma, any form of hemolysis e.g. after snake bites and a variety of drugs e.g. statins.