Hydatid cyst of the parotid gland.

Primary hydatid cyst of the parotid gland is extremely rare, even in the endemic areas. A 23-year-old woman presented with slowly progressive swelling in the right periauricular region. Computed tomography (CT) scan of the head and neck revealed a round, well-demarcated water-density mass in the right parotid gland. At the operation, the cystic mass replacing most of the superficial part of right parotid gland was demonstrated. Superficial parotidectomy was carried out. Histopathological examination confirmed the diagnosis of hydatid disease. CT scan is a valuable imaging method for diagnosis of parotid cystic lesions; however, other acquired and congenital cystic lesions of parotid gland may have similar appearance and should be differentiated. Where the incidence of the disease is high, hydatid cyst of parotid gland should be considered in the differential diagnosis of lesions causing swelling of the parotid area.