Lymphatic tumor emboli of perirenal fat in patient with nephrotic syndrome receiving renal biopsy, ultimately revealed gastric adenocarcinoma with membranous glomerulonephritis

Paraneoplastic glomerular diseases and malignancies

Paraneoplastic glomerulopathies are rare manifestations of neoplastic disease to be distinguished from iatrogenic renal damage. Solid tumors are preferentially associated with membranous nephropathy, whereas Hodgkin's lymphomas are associated with minimal change disease. The most common neoplasia associated with paraneoplastic glomerular disease are carcinomas of the lung and of the gastrointestinal tract. Nephrotic syndrome is the most frequent presentation of paraneoplastic glomerulopathy and the most critical glomerular disease regarding prognosis and patient care. Renal biopsy is recommended in patients with glomerular proteinuria or nephrotic syndrome and cancer, depending on life expectancy and therapeutic options. The primary treatment must be directed at the cancer in all cases. Symptomatic treatment of the nephrotic syndrome with diuretics and ACE inhibitors is justified. Prevention of nephrotic syndrome complications, i.e. thromboses and infections, should also be addressed and systematic regular renal follow-up is warranted. All treatments should be regularly reviewed to avoid toxicity, associated renal function loss or low albumin levels for patients receiving albumin-binding drugs. Epidemiologic studies have low evidence-based value. There is no widely accepted experimental model of the association of glomerulopathy and cancer. Thus, epidemiologic and mechanistic studies are needed to determine the true prevalence of paraneoplastic glomerulopathies and investigate new pathophysiologic approaches.

Nephrotic syndrome as a complication of intravesical BCG treatment of transitional cell carcinoma of urinary bladder

Nephrotic syndrome can be associated with various neoplasms, especially solid tumors and lymphomas. This patient presented with painless hematuria of transitional cell carcinoma of urinary bladder, underwent transurethral resection, but developed recurrence 16 months later. Repeat resection was done and intravesical Bacillus Calmette-Guerin (BCG) injections were started. After six months, the patient developed hypertension and nephrotic syndrome with a biopsy revealing membranous glomerulonephritis, though there was no radiological evidence of tumor. This is the first case of nephrotic syndrome with intravesical BCG instillation in a bladder carcinoma patient.