Advantages of monitoring rT3 and dividing LT3 dose in the treatment of consumptive hypothyroidism associated with infantile hepatic hemangioma

Abstract

Abstract Objectives In consumptive hypothyroidism associated with infantile hepatic hemangiomas (IHH), elevated reverse triiodothyronine (rT3) is known due to elevated D3. This report shows that rT3 is a new indicator of IHH progression and that three divided doses of LT3 per day were more effective than a single dose. Case presentation A 23 day-old boy was diagnosed with diffuse IHH and severe hypothyroidism with high rT3. Propranolol and LT4 were administered. Hemangiomas gradually diminished and rT3 decreased, but the thyroid-stimulating hormone remained elevated, and free triiodothyronine (fT3) did not normalize after 2 weeks of treatment. Liothyronine (LT3) was started as a single dose and then divided into three doses after 1 week, which stabilized thyroid function. Conclusions rT3 levels were less variable and decreased in conjunction with tumor shrinkage; thus, rT3 is an indicator of therapeutic outcomes for IHH. LT3 administered in divided doses aided in managing IHH-associated hypothyroidism.