A Case of Familial Hypercholesterolemia and Cerebrotendinous Xanthomatosis With Multiple Giant Xanthomas

A 56-year-old woman was referred to our hospital for evaluation of multiple infectious giant xanthomas on her upper and lower limbs. She was initially diagnosed with heterozygous familial hypercholesterolemia with a proprotein convertase subtilisin/kexin type 9 (PCSK9) mutation and was administered a PCSK9 inhibitor. However, the infectious state of the giant xanthomas did not improve, despite good control of the patient's low-density lipoprotein cholesterol levels. After further investigation, the patient was diagnosed with cerebrotendinous xanthomatosis. After initiation of treatment with chenodeoxycholic acid in addition to a PCSK9 inhibitor, the xanthoma ulcer gradually improved and eventually healed.