Case of an ivory vertebra.

The differential diagnosis of an osteoblastic vertebral lesion (ivory vertebra) includes metastatic prostate cancer, lung cancer, lymphoma, osteosarcoma and Paget's disease. We report a case of a man who was initially diagnosed with Paget's disease on vertebral biopsy. He failed to respond to conventional bisphosphate therapy. The review of the original biopsy specimen showed metastatic carcinoid tumor involving the bone marrow. The various features of carcinoid tumors metastasizing to the skeleton are briefly reviewed.