Imaging Findings of Solitary Cysticercosis in the Intermuscular Area of the Thigh

Cysticercosis is a disease caused by encysted larvae of the tapeworm Taenia solium. The purpose of this case is to characterize the US and MR imaging features of solitary intermuscuar cysticercosis involving the thigh and to correlate the imaging features with pathologic findings. A patient, female, 54-years old, was hospitalized to treat a mass in the right thigh without trauma history. The overlaying skin was normal. Ultrasonography showed a cystic mass of 2.8 cm in size located in the intermuscular area of the medial aspect of the right thigh. Lesion contained tubular, folded, worm-like structure, which is suggestive of scolex. MRI findings revealed high signal intensity mass on T2-weighted image, showing hypointense on T1-weighted image and irregular thin peripheral enhancement in the medial aspect of the right thigh between gracilis and adductor muscle groups. Sagittal T2-weighted image demonstrated a tubular, hypointense structure located within the lesion corresponding to the worm-like structure seen on ultrasound. Cysticercosis should be kept as a differential diagnosis for any case of focal myositis or subcutaneous swellings. Although it is difficult to diagnose solitary soft tissue cysticercosis, if characteristic scolex can be demonstrated with any imaging modality, the diagnosis of cysticercosis can be easier.