Rheumatoid pseudocyst (geode) of the femoral neck without apparent joint involvement.

Typically, rheumatoid cysts are associated with obvious joint involvement and are located in the subchondral portion of the adjacent joint. Giant pseudocysts (geodes) are uncommon and are characteristically associated with extensive joint destruction. The patient described in this report had a giant pseudocyst of the femoral neck but no joint involvement. To the best of my knowledge, this is the first report of such a manifestation of a giant pseudocyst. As such, it posed a somewhat difficult diagnostic problem.