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Currently filtering by tag: IgA nephropathy

Medullary Angiitis

The attached photomicrographs show the classic histopathology of renal medullary angiitis, a lesion involving the vasa recta of the medulla. The characteristic morphologic findings on renal biopsy include interstitial hemorrhage with associated polymorphonuclear leukocyte infiltration and karyorrhectic debris. Differentiation from acute tubulointerstitial nephritis is essential considering the very disparate etiologies, treatment, and prognosis. Medullary angiitis is most commonly seen in association with ANCA-associated disease but it has also been described in IgA nephropathy as well as in patients on antibiotics in the setting of infection (see ref below). It is an important lesson to recognize as it may be the only...

IgA Nephropathy

Figure 1 shows a renal biopsy from a 29-year-old man with no significant past medical history, who was found to have microscopic hematuria and non-nephrotic range proteinuria. The glomeruli show minimal mesangial matrix expansion and segmental hypercellularity. No crescents are identified. The surrounding tubules appear normal. Figure 2 shows dominant IgA mesangial deposits, consistent with IgA nephropathy. Remember that IgA deposits often persist and are seen in repeat biopsies even in patients who receive immunosuppressive therapy. Also, note the recent recommendation to include the presence or absence of crescents in the Oxford classification score (