Bilateral Achilles tendon enlargement.

Cerebrotendinous xanthomatosis is a rare, autosomal-recessive, lipid-storage disease with accumulation of cholestanol in most tissues, particularly within the Achilles tendons. It has been characterized both clinically and biochemically, and recently from the molecular biological aspect as well. Juvenile cataract, childhood diarrhea, mental retardation, cerebellar ataxia, and tendon xanthomas are the most prominent features of this disease. Bilateral symmetrical firm masses of Achilles tendons may be the first symptom the patient recognizes because it can jeopardize his or her ability to walk. However, the treatment strategies for tendon tumors vary. In a recent case, we diagnosed the disease properly, according to the clinical manifestations and the radiological and laboratory examinations. The genetic mutation was characterized by analyzing sterol 27-hydroxylase from the patient's family (located on nucleotide 599) and led to a nonsense mutation. It is a unique type of mutation that has never been reported to our knowledge. Tendon lesions are characterized by the loss of muscle fibers and accumulation of lipid products. To help the patient regain the strength of the Achilles tendon and walking abilities, a large area of tendon tumor was excised, followed by reconstruction with a tibialis posterior allograft, which is the second strongest tendon in the foot and ankle. Although the use of this type of graft is uncommon, the final result was satisfactory. At the 10-month follow-up examination, the patient could walk easily without pain. This case report suggests that the surgical procedure will provide an alternative for the repair of large-area degenerative Achilles tendons.