An elderly-onset neuroblastoma concomitant with minimal change nephrotic syndrome: the first autopsy case report.

Background Neuroblastoma is a well-known embryonal cancer; however, adult-onset neuroblastomas are rare. The systemic symptoms are related to catecholamine excretion or intraabdominal mass effects. Only two cases of neuroblastoma with nephrotic syndrome have previously been reported. We herein present the first autopsy case of neuroblastoma in an older individual associated with minimal change nephrotic syndrome. Case presentation A 63-year-old man was admitted to our hospital for investigation of general fatigue. His renal function was normal and his urine was negative for protein. A computed tomography scan showed a renal tumor and intraabdominal lymph node swelling. Approximately 4 months after admission, he suddenly developed acute renal failure and severe proteinuria, and hemodialysis was instituted. A computed tomography scan revealed an increase in the size of the renal tumor and lymph nodes. He died 1 month later and an autopsy was performed. The tumor exhibited diffuse proliferation of tumor cells with scant cytoplasm, namely small blue cell tumor with rosette formation. As a result of immunohistochemical study, a neuroblastoma was diagnosed. Despite the patient's severe renal failure, most glomeruli showed no remarkable changes. The tubular epithelium exhibited detachment and vacuolation. Electron microscopic study of the glomeruli showed diffuse effacement of the foot processes. These features indicate a diagnosis of minimal change nephrotic syndrome with acute tubular injury. Conclusions Minimal change nephrotic syndrome is the most common renal manifestation associated with lymphoproliferative malignancies. We here present an extremely rare case of adult-onset neuroblastoma with minimal change nephrotic syndrome.