PageT

Paget's disease of bone, commonly known as Paget's disease or osteitis deformans, is a chronic disorder of bone remodeling characterized by excessive resorption followed by disorganized bone formation. It most often affects adults over the age of 50 and tends to involve the pelvis, skull, spine, and long bones of the limbs. In many cases the disease is asymptomatic and discovered incidentally through abnormal alkaline phosphatase levels or radiographic findings.

The condition is named after Sir James Paget, a British surgeon who described it in the late 19th century. The exact cause remains unknown, but a combination of genetic predisposition and environmental factors is implicated. Mutations in the SQSTM1 gene have been associated with familial cases, and infectious or inflammatory triggers have been proposed though not established.

Clinical features vary. Some people experience bone pain, deformities such as bowing or enlargement of affected bones, and an increased risk of fractures. Involvement of the skull can lead to headaches or hearing loss, while joint irritation may contribute to osteoarthritis in adjacent joints.

Diagnosis relies on clinical assessment, laboratory tests showing elevated alkaline phosphatase, and imaging. X-rays can reveal thickened, expanded bones with a mosaic pattern of woven and lamellar bone; bone scans and CT or MRI help determine extent.

Treatment aims to reduce bone turnover and relieve symptoms. First-line therapy consists of bisphosphonates (for example, alendronate, risedronate, or zoledronic acid). Analgesics, physical therapy, and management of complications are supportive options. Surgery may be needed for fractures, severe deformities, or joint replacement in affected areas. The disease is chronic but manageable for many patients, with rare malignant transformation to osteosarcoma reported.