ESPE Abstracts

Background: Diffuse or multifocal infantile hepatic hemangiomas cause consumptive hypothyroidism due to overexpression of type 3 deiodinase in the endothelium of vascular tumor. Because type 3 deiodinase converts of T₄ to reverse T₃ and of T₃ toT₂, a use of levothyroxine alone may not maintain normal levels both fT₃ and fT₄. T₃ therapy in this order has scarcely been reported. We here present a Japanese case with multifocal infantile hemangiomas, whose fT₃ and fT₄ levels were low and normal respectively. The low level of fT₃ improved with liothyronine alone.

Case report: He was referred to our hospital because of jaundice at the age of 2 months. He showed no signs of hypothyroidism except jaundice. On physical examination, the liver was palpable 3 cm below the right costal margin. Abdominal ultrasonography showed multifocal hemangiomas in both lobes of the liver. Blood tests at this time were as follows: serum total bilirubin 6.4 mg/dl, serum direct bilirubin 0.2 mg/dl, TSH 17.7 μU/ml, fT₃ 1.96 pg/dl, fT₄ 1.48 ng/dl. We diagnosed him as having hypothyroidism due to hepatic hemangiomas. Propranolol (2 mg/kg per day) and liothyronine (0.1 μg/kg per day) were started. We used liothyronine alone for hypothyroidism because only fT₃ was decreased. The thyroid hormone requirement was gradually reduced and the treatment was discontinued at the age of 5 months. At the age of 8 months, His growth and neurological development were normal for age and he was euthyroid.

Conclusion: A use of liothyronine alone can be useful in some patients with hypothyroidism caused by infantile hepatic hemangiomas, especially when their fT₃ level is low, compared to fT₄ level.