Metastases to bones

Metastatic tumors involving the bones may derive from a number of visceral primary sites, and they can assume several histological appearances. In selected instances, diagnostic confusion with some primary bone tumors may eventuate, necessitating the use of adjunctive pathologic studies to reach a final interpretation. This review considers metastatic osseous neoplasms in the small-cell, large-polygonal-cell, and spindle-cell-pleomorphic microscopic categories. The use of immunohistology and molecular analysis to study such tumors is discussed.