Stefanos Michalacos

Evolution of sonographic appearance of the thyroid gland in children with Hashimoto's thyroiditis.

BACKGROUND Although thyroid ultrasound is a valuable tool for the diagnosis and follow-up of patients with Hashimotos thyroiditis (HT), classical sonographic findings are not always present. AIM To calculate the time needed for children with HT and normal ultrasound at diagnosis to develop characteristic sonographic findings. PATIENTS AND METHODS 105 children (23 male and 82 female) with HT (mean age 9.4 +/- 2.9 years) were studied. Physical examination and measurements of TSH and fT4 levels were performed at diagnosis, at 3-month intervals for the first year, and twice yearly thereafter. Thyroid ultrasound was performed at diagnosis and twice yearly thereafter. The median follow-up duration was 18 months (range: 6-61 months). RESULTS The time needed for 30%, 50%, and 70% of children to demonstrate an abnormal thyroid sonographic pattern was 4, 7, and 14 months, respectively. Important factors accelerating sonographic changes were goiter (p = 0.023), hypothyroidism (p = 0.0255), and seropositivity for both thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg) autoantibodies (p = 0.0005). CONCLUSION Sonographic findings of HT are present in 37% of children at diagnosis. Fifty percent of children with normal initial thyroid US will develop changes within 7 months; however, characteristic findings may not develop for over 4 years.

Testicular microlithiasis in siblings: clinical implications

Testicular microlithiasis is a relatively uncommon condition in children. It is characterized by the presence of microcalcifications within the testicular parenchyma. Although it is a benign finding, underlying diseases and other conditions must be ruled out because testicular microlithiasis has been found in association with both benign and malignant lesions in the testes and other tissues. We present two brothers with testicular microlithiasis, and highlight the prevalence, natural history, associated malignant conditions and follow-up recommendations of children diagnosed with testicular microlithiasis.

Malignant Insulinoma in Childhood

Pancreatic tumors constitute a rare surgical problem in infancy and childhood. Insulinomas are rare in all age groups with an estimated incidence of one per 250,000 person-years and even rarer in childhood. We report a 10 year-old girl with malignant insulinoma. The presenting symptom was hypoglycemic attacks. Laboratory investigation demonstrated that the hypoglycemia was due to hyperinsulinism. MRI of the abdomen revealed a mass at the tail of the pancreas. Distal pancreatectomy with splenectomy was performed. Histological examination showed malignant insulinoma with peripancreatic lymph node metastases. One month later abdominal MRI revealed the existence of multiple small metastatic foci in the liver, which were confirmed by In111 octreoscan. Treatment with octreotide was started and the disease is stable after 12 months of therapy.

Cortisol response to adrenocorticotropin testing in non-classical congenital adrenal hyperplasia (NCCAH).

Abstract Background: The adequacy of cortisol response in non-classical congenital adrenal hyperplasia (NCCAH) has not been fully elucidated. The aim was to evaluate cortisol response to adrenocorticotropin (ACTH) stimulation test in children and adolescents with NCCAH and heterozygotes for CYP21A2 gene mutations. Methods: One hundred and forty-six children and adolescents, mean age 7.9 (0.7–17.5) years with clinical hyperandrogenism, were evaluated retrospectively. Thirty-one subjects had NCCAH, 30 were heterozygotes for CYP21A2 gene mutations, while 85 showed normal response to ACTH test. Results: Baseline cortisol levels did not differ among NCCAH, heterozygotes, and normal responders: 15.75 (5.83–59.6) μg/dL vs. 14.67 (5.43–40.89) μg/dL vs. 14.04 (2.97–34.8) μg/dL, p=0.721. However, NCCAH patients had lower peak cortisol compared to heterozygotes and control group: 28.34 (12.25–84.40) vs. 35.22 (17.47–52.37) μg/dL vs. 34.92 (19.91–46.68) μg/dL, respectively, p=0.000. Peak cortisol was <18 μg/dL in 7/31 NCCAH patients and in one heterozygote. Conclusions: A percentage of 21.2% NCCAH patients showed inadequate cortisol response to ACTH stimulation. In these subjects, the discontinuation of treatment on completion of growth deserves consideration.

Ectopic Intrathyroidal Thymus in Childhood: A Sonographic Finding Leading to Misdiagnosis.

Background: During gestation, the primordial thymus migrates from the pharynx to the anterior mediastinum, thus thymic tissue can remain at any point along this path. Intrathyroidal thymic remnants are rare, and their sonographic patterns have only recently been described. This retrospective study presents the sonographic appearance of ectopic intrathyroidal thymus and emphasizes the role of sonography in order to avoid misdiagnosis. Methods: The population consisted of 42 children, 3.5-14 years old, who had a thyroid sonogram performed due to a positive family history or symptoms indicative of thyroid disease, and ectopic intrathyroidal thymus was recognized. Results: In all patients, the same pattern was revealed: a fusiform intrathyroidal lesion, with no mass effect, homogeneously hypoechoic, with diffuse bright internal echoes. The similarity to the characteristic sonographic pattern of the normal mediastinal thymus was crucial for the diagnosis of ectopic intrathyroidal thymic tissue. In 8 cases, a normal elongated thymus was found connected to the thyroid with an accessory lobe embedded in the lower thyroid pole. The above sonographic appearances mimicked a thyroid nodule. Conclusions: Awareness of the sonographic patterns of the ectopic intrathyroidal thymus is mandatory to avoid misdiagnosis. In most cases, further investigation is unnecessary, but sonographic follow-up should be recommended.