Rebecca J Perry

Ultrasound of the thyroid gland in the newborn: normative data

Objective: To establish reference ranges for thyroid length, breadth, depth, and volume in healthy term Scottish infants. Design: Prospective observational study of 100 (49 male) neonates. Length, breadth, and depth were measured, and the volume of each lobe was calculated using the formula for a prolate ellipsoid (volume = length × breadth × depth × π/6). Results: All measurements showed gaussian distribution, with no significant differences between the right and the left lobes. Values (mean (SD) range) were: length (cm), 1.94 (0.24) 0.9–2.5; breadth (cm), 0.88 (0.16) 0.5–1.4; depth (cm), 0.96 (0.17) 0.6–2.0; volume (ml), 0.81 (0.24) 0.3–1.7; combined volume (ml), 1.62 (0.41) 0.7–3.3. Although there was no difference in mean volume between right and left lobes, there was considerable variation (−0.8 to + 0.7 ml) between the two lobes in individual babies. Conclusions: Both lobes should be measured to give a combined volume. Our findings provide a reference against which thyroid hypoplasia or goitre can be evaluated.

Combined ultrasound and isotope scanning is more informative in the diagnosis of congenital hypothyroidism than single scanning

Background: Thyroid imaging is helpful in confirming the diagnosis of congenital hypothyroidism and in establishing the aetiology. Although isotope scanning is the standard method of imaging, ultrasound assessment may be complementary. Aim: To determine the strengths and weaknesses of thyroid ultrasound and isotope scanning in neonates with thyroid stimulating hormone (TSH) elevation. Methods: Babies from the West of Scotland with raised capillary TSH (>15 mU/l) on neonatal screening between January 1999 and 2004 were recruited. Thyroid dimensions were measured using ultrasonography, and volumes were calculated. Isotope scanning was carried out with a pinhole collimator after an intravenous injection of 99m-technetium pertechnetate. Results: 40 infants (29 female) underwent scanning at a median of 17 days (range 12 days to 15 months). The final diagnosis was athyreosis (n = 11), ectopia (n = 12), hypoplasia (n = 8; 3 cases of hemi-agenesis), dyshormonogenesis (n = 5), transient hypothyroidism (n = 2), transient hyperthyrotropinaemia (n = 1) and uncertain status with gland in situ (n = 1). 6 infants had discordant scans with no isotope uptake but visualisation of thyroid tissue on ultrasound. This was attributed to TSH suppression from thyroxine (n = 3); maternal blocking antibodies (n = 1); cystic degeneration of the thyroid (n = 1); and possible TSH receptor defect (n = 1). Conclusions: Isotope scanning was superior to ultrasound in the detection of ectopic tissue. However, ultrasound detected tissue that was not visualised on isotope scanning, and showed abnormalities of thyroid volume and morphology. We would therefore advocate dual scanning in newborns with TSH elevation as each modality provides different information.

Cushing's syndrome, growth impairment, and occult adrenal suppression associated with intranasal steroids

We have previously described iatrogenic Cushings syndrome secondary to intranasal steroids. This report further highlights the potential deleterious effects of intranasal steroids. Nine cases (including the original two cases) are reviewed to show the varied clinical manifestations of adrenal suppression caused by intranasal steroids. Four presented with Cushings syndrome, three with growth failure, while two asymptomatic patients were discovered in the course of pituitary function testing. Four children had dysmorphic syndromes—Downs, Treacher–Collins, CHARGE association, and campomelic dysplasia—reflecting the vulnerability of such children to ENT problems, together with the difficulty of interpreting steroid induced growth failure in this context. Adrenal suppression was seen not only with betamethasone but also with budesonide, beclomethasone and flunisolide nasal preparations. A careful enquiry as to the use of intranasal steroids should be routine in children presenting with unexplained growth failure or Cushings syndrome. Particular vigilance/awareness is required in children with dysmorphic syndromes.

Effect of oxandrolone and timing of pubertal induction on final height in Turner’s syndrome: randomised, double blind, placebo controlled trial

Objective To examine the effect of oxandrolone and the timing of pubertal induction on final height in girls with Turner’s syndrome receiving a standard dose of growth hormone. Design Randomised, double blind, placebo controlled trial. Setting 36 paediatric endocrinology departments in UK hospitals. Participants Girls with Turner’s syndrome aged 7-13 years at recruitment, receiving recombinant growth hormone therapy (10 mg/m2/week). Interventions Participants were randomised to oxandrolone (0.05 mg/kg/day, maximum 2.5 mg/day) or placebo from 9 years of age. Those with evidence of ovarian failure at 12 years were further randomised to oral ethinylestradiol (year 1, 2 µg daily; year 2, 4 μg daily; year 3, 4 months each of 6, 8, and 10 μg daily) or placebo; participants who received placebo and those recruited after the age of 12.25 years started ethinylestradiol at age 14. Main outcome measure Final height. Results 106 participants were recruited, of whom 14 withdrew and 82/92 reached final height. Both oxandrolone and late pubertal induction increased final height: by 4.6 (95% confidence interval 1.9 to 7.2) cm (P=0.001, n=82) for oxandrolone and 3.8 (0.0 to 7.5) cm (P=0.05, n=48) for late pubertal induction with ethinylestradiol. In the 48 children who were randomised twice, the effects on final height (compared with placebo and early induction of puberty) of oxandrolone alone, late induction alone, and oxandrolone plus late induction were similar, averaging 7.1 (3.4 to 10.8) cm (P<0.001). No cases of virilisation were reported. Conclusion Oxandrolone had a positive effect on final height in girls with Turner’s syndrome treated with growth hormone, as did late pubertal induction with ethinylestradiol at age 14 years. However, these effects were not additive, so using both had no advantage. Oxandrolone could, therefore, be offered as an alternative to late pubertal induction for increasing final height in Turner’s syndrome. Trial registration Current Controlled Trials ISRCTN50343149.

Heterogeneous tissue in the thyroid fossa on ultrasound in infants with proven thyroid ectopia on isotope scan: a diagnostic trap

BackgroundThyroid imaging is of proven help in establishing a diagnosis of congenital hypothyroidism in infants. US often shows tissue in the thyroid fossa when radionuclide scintigraphy reveals only ectopic uptake.ObjectiveOur hypothesis was that the use of US alone could lead to the mistaken diagnosis of normal or dysplastic thyroid in cases of scintigraphy-proven thyroid ectopia.Materials and methodsWe undertook a detailed retrospective review and analysis of imaging and concurrent biochemistry in infants with thyroid ectopia, confirmed by radionuclide scintigraphy.ResultsEighteen infants had thyroid ectopia; ten of the original US reports had suggested that cervical thyroid tissue was present. Review showed bilateral tissue in the thyroid fossa in all that was non-thyroidal in nature since, apart from showing no radionuclide uptake, it exhibited some or all of the following typical features: hyperechogenicity, heterogeneity, small size, poor vascularity, and anechoic and/or hypoechoic cysts. Also, extension of the tissue both around and behind the large cervical blood vessels was a universal finding.ConclusionConsiderable experience is required to interpret neonatal thyroid US. We caution against diagnosing a dysplastic/hypoplastic thyroid gland in situ on the basis of US alone, particularly if the tissue exhibits any of the non-thyroidal features described.

Safety and Efficacy of Oxandrolone in Growth Hormone-Treated Girls with Turner Syndrome: Evidence from Recent Studies and Recommendations for Use

There has been no consensus regarding the efficacy and safety of oxandrolone (Ox) in addition to growth hormone (GH) in girls with Turner syndrome (TS), the optimal age of starting this treatment, or the optimal dose. This collaborative venture between Dutch, UK and US centers is intended to give a summary of the data from three recently published randomized, placebo-controlled, double-blind studies on the effects of Ox. The published papers from these studies were reviewed within the group of authors to reach consensus about the recommendations. The addition of Ox to GH treatment leads to an increase in adult height, on average 2.3-4.6 cm. If Ox dosages <0.06 mg/kg/day are used, side effects are modest. The most relevant safety concerns are virilization (including clitoromegaly and voice deepening) and a transient delay of breast development. We advise monitoring signs of virilization breast development and possibly blood lipids during Ox treatment, in addition to regular follow-up assessments for TS. In girls with TS who are severely short for age, in whom very short adult stature is anticipated, or in whom the growth rate is modest despite good compliance with GH, adjunctive treatment with Ox at a dosage of 0.03-0.05 mg/kg/day starting from the age of 8-10 years onwards can be considered.

Hypoechoic thyroid nodules on ultrasound 4 years after prenatal exposure to radioiodine: resolution with thyroxine therapy

We describe an infant inadvertently exposed to radioiodine at 17 weeks gestation. His mother had received 400 MBq of 131I for hyperthyroidism (total T4 178 nmol/L, thyroid stimulating hormone (TSH) <0.1 mU/L, 4‐h 131I uptake 16%). Following cordocentesis at 27 weeks (free T4 12.7 pmol/L, TSH 35.4 mU/L) intra‐amniotic thyroxine was withheld and a male infant was born at 39 weeks gestation, birthweight 3520 g. Cord TSH was low (0.1 mU/L), total T4 151 nmol/L on day 4, the mother having received no medication during pregnancy. Postnatal follow‐up showed mild TSH elevation (11.0–19.4 mU/L) but normal free T4 (9–12.7 pmol/L) during the first 2 years of life following which the child was discharged still untreated. On recall at 4.3 years, TSH elevation persisted (15.4 mU/L) and ultrasound showed several hypoechoic thyroid nodules within the left lobe that disappeared after thyroxine treatment.