Ectopic xanthomas in familial (type II) hypercholesterolemia

Xanthomas ordinarily occur in the skin and tendons of patients with severe hyperlipidemia. These xanthomas include xanthelasma, tuberous xanthoma, tendon xanthoma and eruptive xanthoma. Two patients with hypercholesterolemia are now described with xanthomas found in other locations, one deep in the mediastinum and one in the muscles of the buttock. These masses simulated the occurrence of neoplastic tumors but on pathological and chemical examination proved to be typical xanthomata. Ectopic xanthomas should be considered in the differential diagnosis of masses in patients with familial hypercholesterolemia.