58-year-old female, 3 years after mastectomy now presenting with fracture of femur neck. Resection.
- Infiltration of bone marrow spaces by neoplastic epithelial collections in the form of nests, strands and glandular formation. Cytokeratin positive.
- Destruction of bone structure: clusters of bone marrow fibrosis and new bone formation representing reparative processes, but in generall the destruction process appears to be osteolytic.
Bone metastases are predominantly osteolytic and destructive; even if microscopically there is evidence of new bone formation. Osteoblastic metastases are rare: an important and and typical example is carcinoma of the prostate.