Diagnose This (August 17, 2020)

What is your diagnosis for this patient with nephrotic syndrome?

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The electron photomicrograph demonstrates numerous subepithelial deposits along the glomerular basement membrane characteristic of a Membranous Glomerulopathy. Subsequent staining with an immunoperoxidase stain for Phospholipase A2 receptor (PLA2R) was strongly and diffusely positive in this case consistent with a primary Membranous GN. By light microscopy, the classic findings include thickened glomerular basement membranes and pinholes (or bubbles) and spikes that can be seen along the capillary loops with the Jones silver stain. However, it should be noted that the degree, or severity, of these findings can be extremely variable from case to case and early cases may show no light microscopic changes. Importantly, serologic assays are available for the detection of anti-PLA2R antibodies in the blood and can be used not only for diagnosis but also for monitoring therapeutic response, as well as identifying and predicting recurrence.

References:
Larsen CP, Messias NC, et al. Determination of primary versus secondary membranous glomerulopathy utilizing phospholipase A2 receptor staining in renal biopsies. Mod Pathol. 2013 May;26(5):709-15.

Bomback AS. Management of Membranous Nephropathy in the PLA2R Era. Clin J Am Soc Nephrol 13: 784–786, 2018.