Corticosteroids Therapy for Paraneoplastic Nephrotic Syndrome
Paraneoplastic syndromes are disorders associated with clinical signs and symptoms caused by substances produced by malignant disease and are not directly related to the physical effects of a primary or metastatic tumor.1 We describe a patient who presented with paraneoplastc nephrotic syndrome due to squamous cell carcinoma of the lung. The complications and successes in managing the patient's disease have been discussed. Our literature review indicates timely screening for lung cancer to prevent potentially fatal complications.2
A 57-year-old Asian man who had a history of hypertension, chronic renal insufficiency status after nephrectomy, pericarditis, myocardial infarction, and over 35 years of smoking presented to our facility with shortness of breath on exertion and peripheral edema. Chest x-ray and computed tomography results were positive for loculated pleural effusion, left anterior mediastinal mass, and left upper thoracic pleural-based mass. Initial laboratory reports were positive for high-grade proteinuria, 6.7 g; elevated blood urea nitrogen, 74; and elevated serum creatinine, 5.58. Working diagnosis of acute minimal change disease due to lung cancer was made. Because of the risk of potentially fatal hemorrhage, biopsy was not performed, but steroids were started. Dexamethasone 6 mg intravenous was given on the first day followed by 4 mg intravenous push for 2 days in preparation for chemotherapy. The peripheral edema responded well to Lasix, and the patient reached his baseline ambulation. Creatinine improved from 5.58 to 3.25. He was transferred to the surgical unit. Video-assisted thoracoscopic surgery was performed and biopsy was assessed. The tumor cells from pleural effusion, pleura, and mediastinum showed positive results for cytokeratin AE1-AE3 and p63 consistent with squamous cell carcinoma. However, he developed pneumothorax and was transferred to the critical care unit. Chest tube was placed with improvement in clinical status. Emergent dialysis was performed because of worsening renal function. Care was deescalated from ICU to medical floor. Oncology was consulted, and the patient obtained 2 cycles of chemotherapy in the hospital with continuation of therapy as an outpatient.
Though rare, nephrotic syndrome as first presentation of lung cancer has been reported in the literature further validating the need for chest computed tomography to evaluate for lung cancer.3 Management with steroids and diuresis is recommended as they usually have minimal change disease. Patients with paraneoplastic nephrotic syndrome should be aggressively treated despite their overall poor general condition for early surgical intervention of tumor.