Thyroid “Vise” in an Infant With Neonatal Graves’ Disease

Abstract

On the rare occasion when neonatal goiter is the cause of airway compromise, it typically presents with a palpable neck mass. In the setting of maternal Graves' disease (GD), fetal and neonatal goiters are most commonly caused by maternal treatment with antithyroid medication, and the goiter resolves within days of initiation of thyroxine replacement in the neonate. We describe an atypical presentation of a patient with severe neonatal GD born to a euthyroid mother at 35 weeks' gestational age with respiratory compromise, symptoms of hyperthyroidism, and a nonpalpable thyroid gland. The mother had a history of GD treated with radioactive iodine ablation; during the pregnancy she was treated with levothyroxine throughout and propylthiouracil beginning at 5 months' gestation, for fetal tachycardia. Laboratory testing after birth confirmed neonatal GD. The patient was treated with methimazole, Lugol' s solution, and levothyroxine, and the patient remained euthyroid from day of life 10. After multiple extubation attempts failed, the patient was found on visualization studies to have a large, predominantly posterior, "vise-like" goiter encasing the larynx and upper trachea. The patient was successfully extubated, and all medications were discontinued on day of life 60. The patient remained euthyroid 1 month after discontinuation of treatment. The patient' s atypical presentation illustrates the need for early neck imaging in patients with neonatal GD and respiratory distress, especially when the thyroid gland is not palpable. Treatment options for resolving a goiter due to neonatal GD are not clear.

Management of Neonates Born to Mothers With Graves’ Disease

“…A range from 0.2 to 1 mg/kg per day divided in 1 to 3 doses, with a typical dose of 0.2 to 0.5 mg/kg per day, has been reported. 14,59,64,66,71,73 For full-term newborns, we therefore recommend initiating MMI at 0.625 mg twice daily (0.4 mg/kg per day for a 3-kg newborn). The infant should be assessed clinically and biochemically on a weekly base until stable, then every 1 to 2 weeks with titration of MMI dose as tolerated.…”

“…6,9,35,38 MMI dose should be decreased and eventually discontinued when fT4 levels are within the reference range. Alternatively, the addition of levothyroxine to MMI treatment has been practiced, 9,14,59 although recent guidelines recommend against this "block and replace" practice. 73 The decision to discontinue treatment should be based on clinical status and ongoing normal thyroid hormone levels.…”

“…Findings include goiter with occasional tracheal compression, low birth weight, stare, periorbital edema, retraction of the eyelid, hyperthermia, irritability, diarrhea, feeding difficulties, poor weight gain, tachycardia, heart failure, hypertension, hepatomegaly, splenomegaly, cholestasis, thrombocytopenia, and hyperviscosity. 6,11,[14][15][16][17] Signs and symptoms of neonatal hyperthyroidism are nonspecific and also could be attributed to congenital viral infections or sepsis. 18 The diagnosis of neonatal hyperthyroidism can therefore be overlooked, resulting in preventable morbidity and mortality, with mortality rates up to 20% reported.…”

Case 3: Respiratory Distress and Tachycardia in a Preterm Neonate

“…Given the infant's persistent tachycardia, thyroid disease is considered and evaluated. The thyrotropin level is decreased at 0.01 mIU/mL (normal, 0.34-5.66 mIU/mL) and the levels of total triidothyronine (total T 3 ) and free thyroxine (fT 4 e392 NeoReviews Index of Suspicion in the Nursery 1.2-2.7 nmol/L] and 5.83 ng/dL [75 pmol/L; normal 0.52-1.21 ng/dL, 6.7-15.5 pmol/L], respectively). Although his mother again denies medical problems, the team suspects neonatal Graves disease and starts methimazole and propranolol.…”