What are the most common primary neoplasms that metastasize to osseous structures?
The most common primary cancers that metastasize to osseous structures include prostate, breast, and lung cancers, followed by kidney and thyroid cancers and are remembered by the mnemonic PB (lead) KetTLe. The axial skeleton is more frequently involved than the appendicular skeleton because of the presence of red bone marrow. For this reason, it is also rare to have metastases distal to the elbow or knee, but if metastases are seen in these locations, one should consider lung carcinoma as the potential primary tumor. Lytic osseous metastases must have destroyed 30% to 50% of the bone to be seen on radiographs. Sclerotic osseous metastases appear radiodense. Nuclear medicine bone scans are more sensitive than radiographs for the detection of osseous metastatic disease. Common sites for osseous metastatic disease are the vertebrae, pelvis, proximal femurs, and skull.
