Echinococcosis in an Unusual Site: A Rare Case Report of a Primary Hydatid Cyst in the Thigh

Background: Hydatid disease, caused by the Echinococcus granulosus parasite, primarily affects the liver and lungs. Muscular involvement is extremely rare. A primary hydatid cyst in the thigh is an unusual and rare presentation, as hydatid disease typically affects the liver (70%) and lungs (20%), with muscle involvement being extremely uncommon (0.5–5%). This report presents a case of a primary hydatid cyst in the thigh. Case Presentation: A 30-year-old male patient presented with a swelling in the anterior thigh, which had been gradually enlarging. The patient reported no pain, fever, or trauma. On the basis of local examination, suspected of small cystic swelling, patient was planned for excision. Intra-operatively the swelling was diagnosed as a case of hydatid cyst with multiple cysts in the thigh. This case report marks the significance of preoperative radiological investigations in patients with rare clinical presentation of hydatid disease. Conclusion: Primary hydatid cyst of the thigh is rare but should be considered in differential diagnoses of soft tissue masses, especially in endemic areas.