Primary hydatid cyst of the thyroid glands: two case reports and a review of the literature

INTRODUCTION: Although hydatid cyst remains one of the prevalent parasitic infections in humans, hydatid cyst of the thyroid is extremely rare, even in endemic areas. Here we present two cases of thyroid hydatid cysts. CASE PRESENTATION: A 35 and a 50 year-old Iranian female with a positive history of animal contact were presented with a neck lump without any compressive symptoms. A physical exam revealed neck masses that elevated with swallowing. Thyroid gland ultrasonography showed cystic thyroid lesions, and fine needle aspiration (FNA) suggested a thyroid hydatic cyst. Thyroid lobectomy and isthmectomy were done for the first patient, and near-total thyroidectomy was done for the other. The pathology report confirmed the diagnosis of a hydatid cyst. None of the patients had hydatid cysts in other sites. Patients were discharged without an antiparasitic drug, and no recurrence was detected at the six-month follow-up. CONCLUSION: It is necessary to consider hydatid cysts in the differential diagnosis of cystic lesions of the thyroid gland in endemic areas, especially in people with a positive history of animal contact.