Intraosseous ganglia of the foot.

The purpose of this article is to review the English language medical literature involving intraosseous ganglia and to report the rare finding of a histologically proven intraosseous ganglion found in the calcaneus. Intraosseous ganglia are rare lesions of bone seen in the metaphyses or epiphyses of long bones. The lesion is more common in the lower extremity; however, very few have been reported in the foot. The lesion is usually in close proximity to a joint, but rarely has any communication with it. The intact intraosseous ganglion is smooth and round in shape, with an opalescent color indistinguishable from soft tissue ganglia. The contents of the cyst are of a gelatinous consistency and have mucoid centers with a yellowish color. Patients commonly present with intermittent pain that increases with activity. Radiographically, the lesion appears as a well-defined circular to oval radiolucent defect surrounded by a thin rim of sclerotic bone. Bone lesions with a similar radiographic appearance (giant cell tumors, aneurysmal bone cyst, and enchondromas) must be differentiated from intraosseous ganglia. Curretage of the cyst followed by packing of the defect with bone graft is the treatment most often used.