Diffuse xanthomas in a patient with primary biliary cholangitis and lipoprotein X

PBC: primary biliary cholangitis INTRODUCTION Cutaneous xanthomas are common cutaneous lesions that arise from localized deposits of lipid in the dermis. Their presence often represents an underlying disorder of lipid metabolism. The morphology of cutaneous xanthomas can suggest a particular lipid disorder. For example, the presence of tuberous, tendinous, and plane xanthomas can be associated with primary type II and III hyperlipidemia. Less commonly, xanthomas occur in the setting of secondary dyslipidemia, such as cholestasis in primary biliary cholangitis (PBC). PBC is an autoimmune disease of the biliary tree, which causes progressive destruction of the small intrahepatic bile ducts, resulting in cirrhosis. Dyslipidemia is seen in 75% of patients with PBC and arises in part due to accumulation of an abnormal lipoprotein called lipoprotein X, which carries large quantities of cholesterol in the blood. As a result, patients may present with similar patterns of xanthomas as those seen in type II or III hyperlipidemia. Herein, we present a case of diffuse and multiple types of xanthomas arising in association with lipoprotein X in PBC. Our case demonstrates a constellation of xanthomas that can be seen in cases of lipoprotein X-associated dyslipidemia and reminds us to consider this unique pathophysiology in our workup for xanthomas.