Alveolar Soft Part Sarcoma: Imaging Evaluation.

This case report concerns a 16-year-old boy who developed pain in his right thigh after a soccer game. Imaging studies revealed a pathologic transtrochanteric fracture of the right femur, accompanied by a large expansive intramuscular lesion centered in the deep planes of the adductor musculature. Main imaging findings included intense enhancement and vascularization of the lesion, along with peripheral and central flow voids, the latter described as characteristic of this subtype of soft tissue sarcoma. Alveolar soft part sarcoma is a rare and distinctive sarcoma with an indolent clinical course that typically occurs in young patients and predominantly affects the deep tissues of the lower limbs. · Soft tissue sarcomas are a rare group of malignancies, often found in the extremities. Suspicious features include larger size, deeper location, heterogeneous enhancement, and progressive growth.. · Alveolar soft part sarcoma (ASPS), a rare subtype primarily seen in children, is characterized by high T1 signal intensity, intense contrast enhancement, and more than five central and peripheral flow voids that are highly indicative of this condition.. · Magnetic resonance imaging (MRI) is the preferred modality for evaluating these lesions. Advanced MRI techniques, such as diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC), enhance diagnostic confidence, particularly in postoperative evaluations..