Which cell type is most likely involved in initiating the lesion in Paget disease of bone?

Which cell type is most likely involved in initiating the lesion in Paget disease of bone?

• A. Osteoclasts
• B. Osteoblasts
• C. Fibroblasts
• D. Endothelial cells

Answer: (A)

Paget disease of bone starts with overactive osteoclasts. These large, multinucleated cells aggressively resorb bone surfaces, initiating an accelerated remodeling cycle. In response, osteoblasts overcompensate and lay down new bone rapidly, but in a disorganized way, creating the characteristic mosaic pattern of woven and lamellar bone. Thus, osteoclasts are the primary initiating force behind the lesion. Fibroblasts and endothelial cells play supportive roles in the tissue environment but do not initiate the process, and osteoblasts drive the subsequent, excessive bone formation rather than starting the lesion.

Paget disease of bone starts with overactive osteoclasts. These large, multinucleated cells aggressively resorb bone surfaces, initiating an accelerated remodeling cycle. In response, osteoblasts overcompensate and lay down new bone rapidly, but in a disorganized way, creating the characteristic mosaic pattern of woven and lamellar bone. Thus, osteoclasts are the primary initiating force behind the lesion. Fibroblasts and endothelial cells play supportive roles in the tissue environment but do not initiate the process, and osteoblasts drive the subsequent, excessive bone formation rather than starting the lesion.