Myasthenia gravis with membranous nephropathy, successfully treated with extended total thymectomy

A 46-year-old woman showed proteinuria and hematuria after left blepharoptosis, and revealed a histopathology of membranous nephropathy (MN) at renal biopsy. She was diagnosed as having myasthenia gravis (MG) because of a positive edrophonium test and anti-acetylcholine receptor (AchR) antibodies in serum. We found a decrease in anti-AchR antibodies after extended total thymectomy, in parallel with an improvement in both urinary findings and myasthenic symptoms. In this case, MG preceded MN and the thymectomy was effective for both diseases, suggesting that the thymus might play an important role in the pathogenesis of MN.