Membranous nephropathy resolving with treatment of bronchial carcinoid tumor

The nephrotic syndrome and membranous nephropathy is well recognized in association with solid tumors, although less is understood of the process that links them. We report a 27-year-old man presenting with the nephrotic syndrome and stage I membranous glomerulonephritis on biopsy. A bilar mass with regional lymphadenopathy was found simultaneously, the histology of which was shown to be an infiltrative atypical bronchial carcinoid tumor. The neoplasm was successfully treated with combined chemotherapy and radiotherapy, and over this period his nephrotic-range proteinuria resolved. As has been described with other malignancies, membranous nephropathy associated with a bronchial carcinoid tumor may resolve with treatment of the underlying condition.