Tendon xanthomas: Not always familial hypercholesterolemia.

Tendon xanthoma are most commonly associated with Familial Hypercholesterolemia, but the differential diagnosis includes sitosterolemia and cerebrotendinous xanthomatosis (CTX). The case presented here is of a 48-year old male with large tendon xanthomas attributable to CTX. CTX is a rare, recessive disorder caused by mutations in the CYP27A1 gene. The resultant defect in bile acid synthesis leads to cholestanol deposition in different tissues in the body, including tendons. CTX is associated with neurologic symptoms and a reduced life expectancy. Treatment consists of bile acid supplementation in combination with a statin. When patients present with tendon xanthomas and FH is ruled out, clinicians should consider CTX as a possible diagnosis.