Bone lesions in malignant diseases--I. Current concepts of major pathogenetic mechanisms and forms.

Bones are among the major parts of the body that are targeted in neoplastic diseases. Bone lesions increasing in number and size and diffuse osteoporosis are found in 30-80% of cancer patients. All literature data about the pathogenetic factors of osteolytic and osteosclerotic bone lesions are classified into four groups: 1. Directly connected with the neoplastic tumour mass. 2. Humoral interaction between the tumour cells and bone cells. 3. Systemic effects and complications of the neoplastic process. 4. Extracancerous factors. We discuss here the basic pathogenetic forms of bone lesions in neoplasias: 1. Local osteolysis in the area of neoplastic infiltration. 2. Humorally activated demineralisation with hypercalcemia. 3. Light chain osteomalacia. 4. Hypophosphatemic osteomalacia. We consider the major current biochemical markers of bone remodelling and their use in diagnosing and monitoring bone disease in neoplastic conditions.