A newborn with a massive goiter

A full-term female newborn was admitted to the Neonatal Intensive Care Unit for management of a huge anterior cervical mass. An emergency caesarean section was performed at 42 weeks of gestation because of fetal asphyxia, pelvic presentation, and suspected fetal anomalies (cardiomegaly and tumour of thymus). Birth weight was 3,700 g and Apgar scores were 3 and 6 at 1 and 5 minutes, respectively. Due to severe respiratory distress, the newborn required immediate intubation.

Examination revealed a midline tumour in the neck region, which was soft, mobile, noncystic, without associated inflammatory signs and no bruits audible (Figure 1). The remainder of the examination was normal. Neck ultrasonography (Figure 2) and computed tomography (Figure 3) revealed diffuse thyroid gland enlargement (RL 35×35× 50, LL 40× 40× 45 and isthmus 15 mm). Thyroid function testing revealed an elevated thyroid-stimulating hormone (TSH) 44.84 µIU/mL (normal range 0.35 to 4.94 µIU/mL), low FT4< 5.15 pmol/L (9 to 19 pmol/L) and markedly elevated thyroglobulin >500 µg/L (1.4 to 78 µg/L). The anti-thyroid peroxidase antibody assay was negative. Hearing tests were normal. All these findings confirmed the diagnosis of primary hypothyroidism likely due to dyshormonogenesis, and she was placed on L-thyroxine (15 µg/kg/day) on day 4.

Figure 1.

Newborn with massive anterior neck mass.

Figure 2.

Neck ultrasound.

Figure 3.

CT of thyroid in newborn showing diffuse and massive thyroid enlargement.

A thyroid scan was not performed because the newborn was ventilator dependent, but open thyroid biopsy specimen confirmed thyroid dyshormogenesis. To facilitate thyroid gland shrinkage, we added Lugol’s iodine solution two drops tid for 10 days (8 to 17 days of life). The goiter decreased by 0.5 cm per lobe after 3 days of treatment. TSH levels dropped to 1.67 µIU/ml on the 14th day of life and by the third week of life the goiter was approximately 25% of its original size. She was extubated on the 22nd day of life.

The child was discharged on the 40th day of life and has continued to receive L-thyroxine replacement. During follow-up over next 24 months, her thyroid gland size decreased to almost normal size.

DISCUSSION

Congenital goiter is a rare cause of neonatal neck mass with a incidence of about 1:40,000 deliveries (1). Goiter is seen in 10 to 15% of fetuses with congenital hypothyroidism (CH) (2,3). Large masses can have major fetal and perinatal effects due to the compression and distortion of surrounding cervical structures, most particularly the upper respiratory tract interfering with postnatal oxygenation (4,5). Our patient had severe respiratory distress due to a large goiter, requiring early intubation. Iodine therapy was added to try to achieve a faster reduction in thyroid gland size to avoid the need for prolonged ventilation. We noticed a definite reduction of the goiter size after 3 days and discontinued iodine after 10 days to avoid rebound thyroid enlargement. The goiter continued to decrease and we were able to extubate the child by day 22 of life. In the following months, the size of the thyroid gland normalized with normalization of TSH and free T4 concentrations.

In our case, goiter and CH were not recognized during pregnancy. The neck mass was described as tumour of the thymus and that led to delay in diagnosis and initiation of therapy. At the same time, the enormous goiter was a life threatening condition for the newborn. We started treatment on the fourth day of the newborn’s life and achieved normal level of TSH after 10 days, L-thyroxine dose adjustments were adjusted aiming that FT4 is in high range. Despite this effective treatment, significant reduction of goiter and thyroid gland size, the child has mild neurological delay (6).

The effect of Lugol’s iodine in reducing the goiter size in this newborn is uncertain given the lack of similar children not receiving Lugols. We offer two comments. First, it was our distinct observation that the significant decrease in thyroid volume, observed after both therapies were started, was greater than one would expect from thyroxine replacement alone and, second, that there have been no side effects of this therapy. The putative mechanism of action of the iodine is in blocking the organification of iodine through inhibition of the enzyme thyroid peroxidase (Wolf-Chaikoff effect), thereby protecting the thyroid from further enlargement (7). Since the thyroid is able to overcome the synthetic block induced by the iodine after about 10 days of treatment, this is felt to be the maximum duration of administration that should be contemplated.

CH should be considered in any child with an anterior neck mass on intrauterine ultrasound or postnatal examination. From our experience, iodine treatment added to LT4 should be seriously considered before any invasive approaches are contemplated.

Potential Conflicts of Interest:

All authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.