(216) Goiter in a Newborn with Congenital Hypothyroidism

Introduction: Congenital hypothyroidism rarely causes a clinically significant neck mass in newborns. Here, we present the case of a newborn with hypothyroidism born with a significantly enlarged goiter and discuss relevant considerations for imaging as well as medical and surgical management.

Methods: Case report and literature review.

Results: Our patient was prenatally found to have a 6.0 x 3.4 x 5.8 cm midline neck mass at 28-week anatomy ultrasound with subsequent cordocentesis demonstrating elevated thyroid-stimulating hormone (TSH, 361 µIU/mL). She was born via Caesarean section at 38 weeks, intubated upon birth for airway protection, and given a dose of levothyroxine. Ensuing magnetic resonance imaging (MRI) revealed a 5.5 x 4.4 x 7.6 cm congenital goiter and laboratory studies confirmed the diagnosis of primary hypothyroidism. She was noted to be euthyroid by day-of-life 3 and daily levothyroxine therapy was initiated on day-of-life 9. Serial ultrasounds showed that the goiter decreased in volume by 38% and 62% at two weeks and one month, respectively.

Conclusions: Congenital hypothyroidism occurs in 1:2¬-4,000 newborns, however over 95% present without any clinical manifestations at birth. Congenital goiter can be caused by a variety of disorders, including transplacental transfer of maternal antibodies, genetic disorders, or iodine imbalance. Initial testing should include measurement of serum TSH and thyroxine (T4), which guide the selection of diagnostic antibody tests. Ultrasound or MRI can be performed to confirm diagnosis. Prompt treatment with thyroid hormone replacement is necessary to ensure normal growth and neurodevelopmental outcome. We show that goiter size may dramatically decrease with medical therapy alone. Surgical management should be considered only for those with persistent compressive symptoms despite optimal medical management.