Endocrine Abstracts

Objective: Pendred syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss, goiter, and a partial defect in iodide organification. Pendred syndrome is caused by mutations in the SLC26A4 gene. Here, we report a patient with pendred syndrome and papillary thyroid carcinoma.

Case report: A 19-year-old man admitted to our clinic with swelling in his neck. Congenital hypothyroidism was diagnosed at the age of one. His twin brother and his sister had been diagnosed as congenital hypothyroidism when they were one year old. In physical examination, a visible goiter was present and the thyroid was enlarged with multiple palpable nodules. In laboratory examination serum TSH was 2.1 μIU/ml (0.4 to 4.0), free T4 was 0.87 ng/dl (0.85–1.78), free T3 was 4.21 pg/ml (1.57–4.71) and Thyroglobulin was >300 ng/ml (0–55). Ultrasonographically, there were multiple nodules in thyroid. Thyroid scintigraphy showed hypoactive nodular goitre. Perchlorate discharge test revealed increased uptake and washout. Increased discharge pointed to an organification defect as in Pendred syndrome. Fine needle aspiration biopsies were benign. Sensorineural hearing loss was not detected. Bilateral total thyroidectomy was performed because of cosmetic complaints and enlarged multinodular goitre. Postoperative histopatology was reported as papillary thyroid carcinoma of 13 mm. There was no capsular or vascular invasion. After surgery 100 mCI radioactive iodine was given to the patient and also L-thyroxin was started.

Conclusion: Goiter is the most frequent symptom of Pendred syndrome and associated with an insufficient thyroid hormone synthesis caused by a defect in iodide organification. Pendrin expression has been studied in various human benign and malign thyroid neoplasms. Thyroid carcinoma can be seen in patients with Pendred syndrome. Recurrence of benign thyroid nodules after thyroidectomy in these patients is common. Therefore, if surgical management is considered for any reason in these patients, total/near total thyroidectomy should be preferred.