LAUSR

A hydatid cyst (HC) is a parasitic infection caused by the larva form of Echinococcus. It is endemically present in regions where animal husbandry is prevalent, such as the Middle East, Mediterranean countries, Eastern Europe, South America, Australia, and Turkey. HC is most frequently localized in the liver in humans (75%), followed by the lungs (15%). However, it can rarely be localized in atypical sites such as intramuscular areas or in the subcutaneous tissue and breast. A 47-year-old female patient consulted a physician regarding pain in her left hip and leg that was ongoing for 2 months. Computerized tomography (CT) revealed a mass lesion in the patient with solid and cystic components, 177 mm 3 90 mm 3 78 mm in size, that extended from the anterior part of the kidney to the left inguinal area (Figure 1A). The patient had no known concomitant disease. The lesion had no association with intra-abdominal organs. Upon radiological suspicion of sarcoma in the foreground, a lesion with a thickened wall, starting from the anterior segment of the left kidney and extending to the left inguinal area, with extension in the left iliopsoas trace, sporadic necrotized appearance, and Fluorodeoxyglucose involvement (SUVmax:11.9), was observed with positron emission tomography/computerized tomography (PET/CT) (Figure 1B). A Ultrasound-guided fine-needle aspiration (FNA) and core needle biopsy was performed during the same procedure. FNA was part of the routine diagnostic work up on this case which was suspected to be a sarcomatous lesion of muscular origin at the forefront, accompanied by PET/CT findings. Inflammatory cells were detected on a necrotic background at the core biopsy. Papanicolaou-stained FNA smears were composed of mostly individual and rarely grouped intact protoscoleces (Figures 2 and 3) and hooklets (Figures 4 and 5) on a background composed of inflammatory cells and degenerated and necrotic cell debris. The