Nephrotic syndrome due to membranous nephropathy associated with metastatic prostate cancer: rapid remission after initial endocrine therapy.

A case of severe nephrotic syndrome (urinary protein excretion 12.9 g/day) due to membranous nephropathy associated with untreated prostate cancer and multiple bone metastases is described. A combination of initial endocrine treatment and steroid therapy resulted in normalization of prostate-specific antigen levels followed by a rapid decrease of urinary protein excretion within 4 months. No proteinuria was subsequently detected. Seven months after the initiation of therapy, the patient remained well with complete clinical remission from the nephrotic syndrome. This rapid achievement of remission may have been due to tumor shrinkage by androgen ablation in addition to steroid therapy of the membranous nephropathy. The nephrotic syndrome is a rare complication of prostate cancer, and, to the best of our knowledge, no previous cases have been reported of membranous nephropathy as one of the first disease manifestations.