Presentation of an intermetatarsal ganglion.

Ganglia have occurred in almost all areas of the foot, but most often associated with capsular or tendinous structures. They are fluid-filled masses which often present themselves radiographically as increases in soft tissue density. Ganglia exhibit high intensity magnetic resonance imaging and must be clinically and pathologically differentiated from other masses, such as, but not limited to, neuromas, granulomas, and neurilemomas. The authors present a rare occurrence of an intermetatarsal ganglionic cyst associated with the third dorsal interossei muscle, which was large enough to cause bony deformation of the adjacent metatarsals. It is unusual for ganglia to cause alterations in bone unless they are intraosseus in nature. Bone deformation and invasion are usually associated with aggressive tumors.