Background: Nephrotic syndrome associated with neoplastic diseases occurs in 10.9% of cases; the occurrence of nephrotic syndrome associated with ovarian tumors, however, is rare. Cancer antigen 125 (CA-125) is a high-molecular mass glycoprotein of 220 kDa, produced by epithelial ovarian tumors and by mesothelial cells. Radioimmunoassay for serum CA-125 determination has been proposed for monitoring the efficacy of therapy and for early detection of recurrence. Elevated serum CA-125 levels have been demonstrated in a number of benign gynecologic as well as benign and malignant nongynecologic conditions.
Case Report: A patient with nephrotic syndrome associated with renal amyloid involvement and considerable increase in CA-125 in serum is herein described. Thus far in the literature there is no data about such an increase of the level of CA-125 in nephrotic syndrome.
Conclusions: Clinical usage of the tumor marker is being limited to its low specificity. An increase in CA-125 among patients with fluid in body cavities should be interpreted very carefully.

Keywords: nephrotic syndrome, CA-125, neoplastic disease, Amyloid, ovarian tumor