A 40-year-old woman has been followed up for 19 years by the endocrinology clinic with the diagnoses of Addison disease and primary hypothyroidism. During the most recent visit of the patient, she complained about fatigue and malaise with pretibial edema. In albumin analysis: 2.2 gr/dL and 5.8 g/day proteinuria were detected. In terms of nephrotic syndrome etiology, renal biopsy was performed and it was considered as minimal change disease. The dose of 7.5 mg/day methyl prednisolone was potentiated to a dose of 1 mg/kg/day. During her control, the proteinuria did not regress and 150 mg/day cyclophosphamide was added to the treatment. During the control, her proteinuria regressed from 5.8 r/day to 1.95 mg/day.