Diagnose This (March 30, 2020)

What is the name of this rare finding typically seen in the outer medulla?

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The light microscopic image of a PAS stain reveals tubular epithelial cells with PAS positive glycogen accumulation which after diastase digestion would be PAS pale, consistent with the Armanni-Ebstein lesion.

The Armanni-Ebstein lesion, described initially in the 1800s, is typically seen in poorly controlled diabetics and patients with diabetic ketoacidosis as in our case where the patient was previously diagnosed with type 1 diabetes. However, this change is somewhat non-specific as it has also been reported in other metabolic derangements such as alcoholic ketoacidosis and Fanconi syndrome (see references). By location, this change predominately affects the terminal straight portion of the proximal convoluted tubule and thus is typically located at the corticomedullary junction involving the outer medulla and partially, the inner cortex. Interestingly, the name “Armanni-Ebstein lesion” has also been used in insulin-dependent diabetics to describe subnuclear, PAS-pale vacuolization of proximal tubules that are not restricted to the outer medulla which show positive staining for neutral lipids.

References:

1. Zhou C, Yool AJ, Nolan J, et al. Armanni-Ebstein lesion: a need for clarification. J Forensic Sci. 2013; 58: S94-8.
2. Parai JL, Kodikara S, Milroy CM, et al. Alcoholism and the Armanni-Ebstein lesion. Forensic Sci Med Pathol. 2012; 8: 19-22