Which histologic feature is most characteristic of Paget disease of bone?

Which histologic feature is most characteristic of Paget disease of bone?

• A. Uniform lamellar bone without cement lines
• B. Osteoid deposition by osteoblasts
• C. Subperiosteal new bone formation with epithelioid infiltration
• D. Haphazardly oriented cement lines creating a mosaic pattern

Answer: (D)

Paget disease of bone reflects abnormal remodeling with cycles of rapid resorption followed by disorganized bone formation. The key histologic feature is lamellar bone arranged in irregular, haphazard packets separated by prominent cement lines, producing a mosaic or “jigsaw puzzle” appearance. This interlocking mosaic pattern is what distinguishes Paget disease from normal bone or other conditions. Uniform lamellar bone lacks this irregular organization, osteoid deposition without mineralization points to other disorders, and subperiosteal new bone with inflammatory infiltrates suggests osteomyelitis rather than the mosaic remodeling characteristic of Paget disease.

Paget disease of bone reflects abnormal remodeling with cycles of rapid resorption followed by disorganized bone formation. The key histologic feature is lamellar bone arranged in irregular, haphazard packets separated by prominent cement lines, producing a mosaic or “jigsaw puzzle” appearance. This interlocking mosaic pattern is what distinguishes Paget disease from normal bone or other conditions. Uniform lamellar bone lacks this irregular organization, osteoid deposition without mineralization points to other disorders, and subperiosteal new bone with inflammatory infiltrates suggests osteomyelitis rather than the mosaic remodeling characteristic of Paget disease.