The most common carcinomas to metastasize to the skeleton are prostate, breast, lung, thyroid, kidney, and bladder. The malignant cells travel via the bloodstream to the bone. Carcinomatous metastases from the thyroid, kidney, and lower bowel are predominatly osteolytic in nature, causing resorption of bone. Other tumors, such as the prostate and malignant carcinoid tumors, produce a more osteoblastic response, causing the lesion to be more dense than the surrounding tissue. Metastatic carcinoma from the breast can cause both osteolytic and osteoblastic lesions.
Treatment is usually palliative.