Subchondral metastasis: report of five cases.

Subchondral metastasis is a rare occurrence and poses a diagnostic dilemma as initial films may show a lytic lesion in the subchondral region often misinterpreted as being benign. We present five cases of subchondral metastasis as well as a review of the literature. In our cases, we present subchondral metastasis in the elbow, shoulder, and hip joints. All patients had pain over the affected joint and most presented with a lytic lesion in the subchondral bone. Three patients have died since presentation and two are doing well at last follow up visit. Subchondral metastasis is a rare entity, but it should be included in the differential of a lytic lesion in the subchondral bone.