Introduction
Introduction
36 year old female patient presenting to the hospital complaining of nausea and vomiting. She is found to have acute kidney injury and a serum creatinine of 679µmol/L (normal 53-106). The patient is anuric.
A renal biopsy is performed.
The PAS and trichrome stains reveal the following histological findings.
Go to Question 1
Discussion
Discussion Case 12
Question #1: The patient has an acute kidney injury secondary to narcotics prescription for pain related to metastatic breast carcinoma. The intake of this medication led to rhabdomyolysis and subsequent myoglobinuria which induced acute tubular injury. The first two photomicrographs highlight the tubular casts containing myoglobin and although, the brown pigmentation characteristic of myoglobin casts is not noted in this case, however, the casts have a granular appearance and globules-like formation, and on the trichrome stains are bright red as has been described in the literature. The tubules show evidence of acute tubular injury with flattening and focal loss of the epithelial tubular cells, as well as regenerative changes highlighted by the mitotic activity in the tubules.
Question #2: The third photomicrograph further support the diagnosis, as immunohistochemistry positivity staining, is based on an antigen- antibody reaction taking place on the slide. In this case the antibody coupled with the chromogen is the anti-myoglobin and the tubular casts contain myoglobin, hence, the brown coloration noted on the photomicrograph.
