MR Imaging of Uncommon Soft Tissue Tumors in the Foot: A Pictorial Essay

neoplastic soft tissue masses. Although it contains a relatively small amount of somatic soft tissue elements, the foot is rich in tendons, fasciae, retinaculae, and synovium (1). In the Armed Forces Institute of Pathology series[LKH1], 8% of benign soft-tissue tumors and 5% of malignant soft-tissue tumors occurred in the foot and ankle, suggesting an unexpectedly high incidence on a tissue volume basis. In general, benign tumors occur at least 10 times more frequently than malignant soft tissue tumors. In one series of soft-tissue tumors of the foot and ankle, 87% of lesions were benign (2). Of all the imaging modalities, MRI demonstrates superior soft tissue characterization and is now considered the gold-standard imaging technique in their investigation. Lately, we have encountered rare benign masses and malignant soft tissue tumors of the foot. The presented cases include benign masses such as granuloma annulare, angiomyoma, neural fibrolipoma, and giant cell tumor of tendon sheath, as well as malignant tumors such as melanoma, synovial sarcoma, rhabdomyosarcoma and extraskeletal myxoid chondrosarcoma. There are few published English reports addressing the MR appearance of these masses. This pictorial essay shows MR features of uncommon soft tissue tumors of the foot with associated clinicopathologic findings.