Nephrotic syndrome as a possible indicator of colonic cancer: A case report

The concept of paraneoplastic syndromes encompasses a spectrum of indirect clinical manifestations caused by secretion of bioactive products by malignant cells. Paraneoplastic glomerulopathy represent a distinct clinical entity where nephrotic syndrome can arise as a manifestation of underlying malignancies, particularly solid tumors. Membranous nephropathy is notably associated with such malignancies, highlighting the intricate relationship between nephrotic syndrome and cancer. The present study reports the case of a 44-year-old Caucasian male, smoker (22 pack-years) and chronic ethanol consumer who presented in the Emergency County Hospital of Craiova in March 2018 with abdominal distension, genital and leg edema and no prior medical history. Laboratory tests revealed inflammatory syndrome (erythrocyte sedimentation rate=110 mm/h, fibrinogen, 150 mg/dl, high levels of C reactive protein=6.87 mg/dl), as well as hypoproteinemia (total protein levels=3.90 g/l), hypertriglyceridemia=213 mg/dl, hypercholesterolemia=475 mg/dl, total urinary protein excretion of 12,500 mg/24 h and normal levels of urea (38 mg/dl) and creatinine (0.90 mg/dl). After meeting the diagnostic criteria for nephrotic syndrome (edema, proteinuria, hypoalbuminemia, and hyperlipidemia, it was investigated whether the syndrome was primary or secondary in origin. Notably, an unexplained inflammatory syndrome in conjunction with elevated tumor marker levels (carbohydrate antigen 19-9, 82.47 U/ml; Carcinoembryonic antigen-CEA=9.46 ng/ml) prompted a thorough imagistic investigation, using computer tomography. A polyp was discovered during colonoscopy, prompting a biopsy. The presence of adenocarcinoma was confirmed by histopathological analysis. The only clinical manifestation of the colonic malignancy was the symptomatic presentation of nephrotic syndrome, which led to early detection of the underlying cancer. Paraneoplastic nephropathy connects kidney disease with systemic cancer, showing that renal symptoms may aid in diagnosing hidden malignancies. Nephrotic syndrome, especially membranous nephropathy, is associated with various solid tumors. The present case demonstrated that paraneoplastic syndrome, though rare, may lead to early cancer detection. Ongoing research is essential for improving understanding, targeted therapy and patient management.