ESPE Abstracts

Background: Cervico-facial hydatid cyst is rare. It has a high incidence rate in regions with a mild climate such as Mediterranean countries, Middle East, South America, New Zealand, Australia and Southeast Asia. Hydatid cyst develops most often in the liver and lungs in human beings. The incidence of hydatid cysts in the thyroid gland is rare and it accounts for 1% of echinococcosis locations. Primary hydatid cyst of thyroid gland is an exceptional localization even in echinococcal disease is endemic.

Methods: A 12-year-old male presented with left neck swelling. His medical history and other physical examination findings were unremarkable. The results of blood tests; complete blood count, blood biochemistry and thyroid function tests were normal. Ultrasonography showed one cystic lesions 2.6x3.5x3.7cm in diameter in the left lobe of the thyroid gland and the right lobe was normal. In addition, computerized tomography of the neck described it is as circumscribed, well-defined cystic lesion in the left thyroid lobe without calcification and contrast enhancement. He was scheduled for surgery as a case of left thyroid lobe cyst. He underwent a left thyroid lobectomy.

Results: The postoperative gross examination showed a thick fibrous wall separated the cysts from the surrounding thyroid parenchyma with presence of multiple daughter cystic lesion seen within Left thyroidectomy specimen. Furthermore, the histopathological examination, reported the presence of daughter hydatid cysts of Echinococcus granulosa infection within thyroid tissue. Furthermore, the radiological investigations failed to identify any other evidence of systemic hydatidosis. In addition, the patient was demonstrated in the first month after operation, laboratory evidence of subclinical hypothyroidism with TSH 8 then 10.6 uIU/mL with normal free T4. He started treatment with Levothyroxin tablet. After nine months of follow-up post-operation, he was documented a normal thyroid function and a repeated examination showed no recurrence of the hydatid disease.

Conclusion: hydatid cyst in the thyroid gland is rare. It should be included in the differential diagnosis of cystic lesions of the thyroid gland, especially in endemic regions. Positive diagnosis can be difficult during preoperative period. Exclusively surgical treatment is indicated, ideally for total cystic resection without rupture and the macroscopic aspects with histopathological examination is needed to confirm the diagnosis. Our case represents the first reported patient with primary hydatid cyst of the thyroid gland in a Libyan child.