Histology from a bone biopsy from proximal femur is given below of a 50 year old with bone pain. What is your diagnosis?
High-Yield Explanation
Ref. Robbins Pathology. 9th edition. Page. 1191
Paget Disease
Diagnostic features are increased osteoclastic and osteoblastic activity with supportive radiologic findings
Acute: primarily woven bone; focal mosaic pattern of lamellar bone, resembles jigsaw puzzle with prominent irregular cement lines; osteoclasts present at surface of bone but don’t tunnel; in osteolytic phase, osteoclasts may have up to 100 nuclei
Chronic: thick trabeculae and thicker bones; fine fibrosis of marrow (Osteosclerotic stage)
The picture is also known as mosaic pattern of bone