Lipoprotein-X: A Case of Falsely Elevated LDL Hypercholesterolemia

Lipoprotein-X is an extremely rare cause of severe hyperlipidemia. We present a case of a 26-year-old man with primary sclerosing cholangitis who developed lipoprotein X-induced pseudohyponatremia with severe hyponatremia. In this case report, we also discuss the diagnostic approach and the treatment for lipoprotein X. (Level of Difficulty: Advanced.).