Difficult treatment of consumptive hypothyroidism in a child with massive parotid hemangioma.

Consumptive hypothyroidism is a rare condition related to massive infantile hemangiomas producing an excess of the thyroid-hormone-inactivating enzyme type 3 iodothyronine deiodinase. We report the first case of consumptive hypothyroidism secondary to a large parotid hemangioma, highlighting the difficulties in selecting an adequate therapeutic strategy. The affected child was initially referred to our center for congenital hypothyroidism with a hypoplastic thyroid gland. L-Thyroxine (L-T4) replacement therapy was started at seven days of life. In the following weeks, the hemangioma rapidly increased in volume and the child developed severe hypothyroidism refractory to high doses of L-T4 therapy. The concentration of reverse triiodothyronine was elevated, suggesting that the underlying cause was an excessive conversion of thyroid hormones by high type 3 iodothyronine deiodinase levels in the tumor. Corticosteroid treatment showed only partial benefit. Introduction of propranolol instead led to normalization of thyroid hormones along with a dramatic involution of the hemangioma.