An exceptional localization of hydatidosis

A 48-years-old woman, presenting a huge mass of the posterior surface of the thigh, fixed on the deep and superficial planes, evolving for 1 year. The patient has no particular pathological history, and no other signs were noted, including neither weight's loss nor general deterioration. The patient doesn't have any inguinal adenopathy or abdominal masses on the clinical examination, but she complains paresthesia in the popliteal sciatic nerve's territory. A biological report showed a hypereosinophyly, and MRI was performed, showing a septated cystic mass measuring 24 cm of the major axis, compressing the great sciatic nerve.