Minimal change nephrotic syndrome associated with malignant thymoma: case report and literature review

We report on a patient with nephrotic syndrome with myasthenia gravis and malignant thymoma status post thymectomy and radiotherapy. This 44-year-old woman underwent a thymectomy and localized radiotherapy for invasive thymoma in 1991. She also took azathioprine and pyridostigmine regularly for the control of her symptoms of myasthenia gravis following thymectomy. Neither evidence of recurrence of myasthenia gravis, nor enlargement of residual thymoma was noted following treatment in 1991. Unfortunately, this patient developed a pronounced nephrotic syndrome in 1999, a renal biopsy revealing a minimal-change glomerulonephritis as being present. The patient entered remission subsequent to steroid and cyclosporin therapy, whereas many previously-reported cases of a similar nature either died or remained with a persistent proteinuria. Herein, we review the literature pertaining to examples of nephrotic syndrome for those patients diagnosed with malignant thymoma, and discuss the possible mechanisms for this association, and emphasize the need for the aggressive treatment of the condition, recommending the early use of steroids and cyclosporins.