Paraneoplastic Nephrotic Syndrome in a Teenager with Ovarian Teratoma: Successful Treatment with Tumor Resection and Ovarian Tissue Preservation

Nephrotic syndrome is typically associated with primary glomerular diseases but can occasionally manifest as a paraneoplastic phenomenon.We present the case of a 14-year-old girl who developed nephrotic syndrome accompanied by significantly elevated CA 19-9 levels.She was subsequently found to have a 7 cm mature ovarian teratoma.Despite a non-diagnostic renal biopsy, imaging studies and tumor marker analyses guided the decision to surgically remove the tumor while preserving ovarian tissue.Postoperatively, her nephrotic syndrome resolved completely, and CA 19-9 levels normalized within a month.This case underscores the importance of considering paraneoplastic causes in unexplained nephrotic syndrome and highlights the critical role of timely diagnosis and a multidisciplinary approach in achieving full recovery.