Multiparametric US and MRI Features of Femoral Myxoid Liposarcoma—Case Report and Literature Review

Background/Objectives: Myxoid liposarcoma (MLS) is a malignant soft-tissue tumor and the second-most common subtype of liposarcoma, often occurring in the lower limbs of middle-aged patients. Case Presentation: A 38-year-old male patient presented to the ultrasound outpatient clinic with a large mass in the right femoral region. It has been present for 15 years and mostly stable in size. Over the last two years, it has been slowly increasing in size, more rapidly in the previous 10 months, and has started to limit his range of motion. After multiparametric ultrasound and magnetic resonance imaging evaluation, the proposed diagnosis was myxoid liposarcoma. Following imaging workup, the patient was referred to the tertiary sarcoma center, where a biopsy was performed, and pathohistological diagnosis was low-grade myxoid liposarcoma. Contrast-enhanced computed tomography (CT) evaluation of the thorax, abdomen, and pelvis showed no signs of dissemination, and CT angiography showed no signs of vessel infiltration. Plastic surgery and vascular surgery specialists performed the extirpation of the mass with the partial resection of the adjacent sartorius muscle and the complete resection of the great saphenous vein. Subsequent pathohistological analysis of the mass and local lymph nodes showed clear surgical margins and no lymphatic or vascular invasion. The patient is currently under regular surveillance by an oncology specialist and awaiting adjuvant radiotherapy. Conclusions: A multidisciplinary approach is essential in the management of patients with MLS, as it provides a tailored, individualized assessment from diagnosis through treatment to ensure the best possible outcome.