Primary subcutaneous hydatid cyst over thoracic spine: a case report and review of the literature.

Hydatid disease is a public health problem in endemic areas. Although it is most commonly present in the liver and lung, it rarely affects other tissues. A 62-year-old female patient was admitted to our outpatient clinic with a palpable, moderately mobile mass over the thoracic spine. On MRI, a cystic lesion, hypointense and hyperintense on T1- and T2-weighted scans, respectively, was detected. During surgery, a well capsulated cyst was excised en bloc. On histological examination, a hydatid cyst was diagnosed. Her postoperative serological test was positive. Her whole body was scanned for any other organ involvement, but scans were all negative. She was treated with albendazol. After 3 months, the test result was negative, and there were no local or systemic recurrences. Primary subcutaneous tissue involvement is a rarely reported entity in the literature. To the best of our knowledge, this is the first case report of a primary subcutaneous hydatid cyst detected over the thoracic spine.