Histology Course S IX 13 Department of Pathology, University of Zurich Histology Course

S IX 13 invasive ductal carcinoma of the breast, bone metastases   IHC: LU-5  
  ICD-10: C79.5; ICD-O: 8500/6

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.