Alveolar rhabdomyosarcoma is a malignant tumor of the primitive mesenchyme that occurs in adolescents and young adults. It is associated with a t(2;13) translocation. Patients typically present with a rapidly growing painless mass. Nodal metastasis are known to occur with rhabdomyosarcoma, so sentinel lymph node biopsy should be considered as part of treatment. On MRI, alveolar rhabdomyosarcoma appears like many soft tissue tumors, demonstrating hypointensity on T1-weighted images and hyperintensity on T2-weighted images. Histologically, it is characterized by cellular aggregates of poorly differentiated round cells and multinucleated giant cells that are surrounded by dense fibrous septae.