Evaluation of the patient with carcinoma of unknown origin metastatic to bone.

Metastatic carcinoma to bone of uncertain primary origin is a common clinical diagnostic scenario. I present a simple and effective staging system to identify primary malignancies. The role of clinical history, physical examination, laboratory studies, and limited radiographic studies are critical to the success of this diagnostic strategy. Needle or open biopsy frequently is needed yet usually is more effective as a confirmatory study for carcinoma or to rule out primary bone sarcomas. Patients who present with a displaced pathologic fracture require an urgent diagnostic and treatment plan that does not compromise future treatment options and provides durable skeletal reconstruction.