Relapse of Membranous Nephropathy Following Adrenalectomy for Cushing Syndrome: A Case Report.

Hypercortisolemia in Cushing syndrome (CS) may exert a protective effect against the membranous nephropathy (MN) activity. We report the case of a 59-year-old woman who was diagnosed with stage I MN by renal biopsy 10 years earlier, and achieved complete remission after one year of glucocorticoid therapy. After adrenalectomy for CS (preoperative cortisol level, 18.3 μg/dL), her proteinuria increased. A repeat renal biopsy revealed progression to stage III MN (cortisol level, 0.3 μg/dL). Glucocorticoid and calcineurin inhibitor administration resulted in complete remission. The temporal association between cortisol withdrawal, adrenal insufficiency, and MN progression highlights the need for careful monitoring of rebound immune activation after hypercortisolemia correction.