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.

We describe a case of the Schinzel-Giedion syndrome, where increasing ventriculomegaly, intraventricular bands, and subependymal pseudocysts were shown by ultrasound of the head. Subsequent neuropathology confirmed the hydrocephalus.The Schinzel-Giedion syndrome is a rare form of lethal dwarfism. 1-3 Apart from physical abnormalities, these infants show gross neurological dysfunction. We report a further case, detailing the appearance of the brain on ultrasound and at necropsy. Case reportThis was the first pregnancy of an unmarried, healthy, 18 year old woman. The parents were unrelated. The mother was unsure of the date of her last menstrual period. At booking for antenatal care, the fetus was 34 to 35 weeks' gestation by ultrasound scan and there was polyhydramnios. Ten days later a baby girl of unusual appearance was born in good condition.The infant was markedly dysmorphic (fig 1). The facies were coarse with full cheeks and plentiful facial hair. The skull was brachycephalic with widely spaced sutures and a prominent forehead. The eyes were also widely spaced with periorbital oedema and a mongoloid slant. There was a snub nose with anteverted nostrils and a short philtrum. The ears were abnormally shaped and low set. The neck was very short. There were hypoplastic nipples, but otherwise the chest, heart, and abdominal exaiination was normal. A deep interlabial sulcus was noted, continuous with the fold of the buttock. Her limbs were short with very small hands and feet. There were bilateral simian creases. Head circumference at 31 cm and weight at 2100 g were on the third centile. Length at 39 cm was markedly below the third certile. The estimated gestation was 36 weeks by appearance, agreeing with the antenatal scan.Apart from initial hypoglycaemia (lowest blood sugar 1 1 mmol/l at 10 hours) routine haematology and biochemistry were normal. Chromosome analysis showed a normal female karyotype by Giemsa banding. Head ultrasound showed moderate dilatation of the third and lateral ventricles. The lateral ventricles also contained echogenic bands and there were large Department of Paediatrics, Dumfries and Galloway Royal Infirmary, Dumfries DGI 4AP.

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True gigantism is rare in early childhood and is usually due to excess GH secretion from a pituitary adenoma. We report a case in which the endocrine abnormality is secondary to an optic glioma. Careful endocrine evaluation has shown that GH peak amplitude was not increased but rather there was failure of GH levels to suppress to baseline and a lack of pulsatility. There is no evidence of a direct secretory role for the tumour and we postulate that the tumour is affecting GH secretion through an effect on somatostatin tone. Specific tumour therapy is not indicated for this patient in the absence of mass effect or visual disturbance. The GH excess is being treated with somatostatin analogue (Octreotide) and as he has developed precocious puberty he is also receiving long acting GnRH analogue (Zoladex). This boy appears likely to have neurofibromatosis type 1 (NF1) which raises the question of subtle GH excess in NF1 patients with tall stature.