Unusual Location of Primary Hydatid Cyst: Soft Tissue Mass in the Supraclavicular Region of the Neck

Cystic hydatid disease is a zoonosis caused by Echinococcus granulosus. It may affect any organ and tissue in the body, in particular the liver and Lung. Musculoskeletal or soft tissue hydatidosis accounts for about 0,5%-5% of all echinococcal infections in endemic areas and is almost secondary to the hepatic or pulmonary disease (Karaman et al., 2011; Dirican et al., 2008; Kouskos et al., 2007). Case Presentation. We report an unusual case of primary subcutaneous hydatidosis in the left supraclavicular region of the neck. A 53-year-old female patient was admitted with three-month history of pain and gradually growing mass located in the left supraclavicular region. Physical examination revealed a moderately hard, painful, and erythematous mass. The blood cell count was normal. Computed tomography demonstrated, a multilocular cystic lesion with thin borders and thin wall. The mass is binocular and extends to the scapula. CT showed no involvement of the lung. From these signs, the patient was diagnosed as having abscess (bacterial infection or tuberculosis). The diagnosis of Echinococcus granulosus infection was made per operatively after visualization of the cyst wall and the daughter cysts. Following irrigation of cystic cavity with hypertonic saline solution, the cyst wall was excised along with a portion of surrounding tissue. Histopathological examination of the specimen confirmed the hydatid origin. Hemagglutination tests for Echinococcus and ELISA were negative. Ultrasound of the abdomen was normal. The patient received albendazole (400 mg/day) for 8 weeks postoperatively. No sign of recurrence could be detected by physical examination and imaging (CT) at 4-month followup. Conclusion. The case illustrates that echinococcal disease should be considered in the differential diagnosis of every cystic mass in every anatomic location, especially when it occurs in endemic areas.