ESPE Abstracts

Background: Thyroid nodules in children are less common than in adult but are about two-to three-fold at risk of being malignant compared to adults. Plummer's adenoma is a very rare occurrence in pediatrics; there is no literature evidence of this diagnosis in Prader-Willi Syndrome (PWS).

Case Presentation: A 9-year-old boy, followed at our Pediatric Endocrinology Outpatients Clinic for PWS (maternal uniparental disomy), diagnosed in neonatal period, presented with the appearance of a rapidly growing palpable mass at the left anterior cervical site in the thyroid lodge. Familiar history was negative for thyroid diseases. The patients, in therapy with recombinant human growth hormone (rhGH) since the age of 1-year-old, had regular growth in height and weight: height 130 cm (+0,05 DS), weight 36.7 kg (+1,48 DS), BMI 21.75 (+1,67 DS); regular growth rate (7.6 cm/year). The child was prepubescent in accordance with the Tanner Stage. Thyroid biochemical assessment, initially within normal limits, over about 2 months shifted toward a subclinical hyperthyroidism: TSH (0.005 uIU/mL; normal value 0.27-4.2), free triiodothyronine (fT3 5.79 pg/mL; n.v. 2.0-4.4), free thyroxine (fT4 20.4 pmol/L; n.v. 12.0-22.0); anti-thyroglobulin (AbTg), anti-perossidase (AbTPO) and TSH receptor (TRAB) antibodies were negative. Thyroid ultrasound documented the presence of a nodule of the left lobe (longitudinal diameters, LD 18 mm) with disomogeneous structure and microcalcifications, with evidence of vascular signs. Fine needle aspiration biopsy (FNAB) was suggesting for non-malignant lesion/adenomatousus struma (TIR 2). A scintigraphic examination was carried out that documented a defined focal uptake of iodine-123 in the nodule with suppressed uptake in the rest of the gland. Due the clinical presentation associated with the laboratory and instrumental findings, patient underwent left hemi-thyroidectomy surgery. The anatomo-pathological examination reported an hyperfunctioning follicular adenoma, confirming the diagnosis of Plummer’s adenoma.

Conclusion: Plummer’s Adenoma is a rare cause of hyperthyroidism in pediatric population. Surgery is the only therapeutic option in children with less than 10-year-old. Our case describes the first evidence of isolated follicular adenoma in children with PWS. Further evidence are necessary to asses a possible correlation between these two conditions and the existence of potential risk factors.