Paget's Disease is a chronic (long-term) disorder that typically results in enlarged and deformed bones.
Excessive bone breakdown and formation cause thick and fragile bones, and as a result, bone pain, arthritis, noticeable deformities, and fractures can occur.
The disease can affect any bone of the body, but the most common sites of malignant transformation are the femur, pelvis, humerus and craniofacial bones in that order. It is also often found in the spine.
The blood supply that feeds healthy nerve tissue may be diverted to the area of involved bone. Also, structural deformities of the involved vertebrae can cause narrowing of the spinal canal, producing a variety of neurological symptoms.
Sufferers whose condition extends to Paget's Sarcoma have a very poor prognosis, with as little as 8-10% survival chance after 5 years. Factors contributing to mortality include the aggressive and high grade anaplastic tumors, the poor health of the age group (most patients are 55-80 years old) in which it occurs and surgically inaccessible tumor sites
Paget's sarcoma usually presents itself as a new, progressive pain in a patient with long standing Paget's disease. Other symptoms can include soft tissue swelling or pathological fractures. The serum alkaline phosphatase which is elevated with Paget's disease may rise further with onset of sarcoma.
Patients often complain of pain before the tumor can be easily seen on a plain radiography and the diagnosis can often be delayed. Eventually, cortical destruction and an ill defined tumor mass extending into the soft tissue with a background of Paget's disease become apparent. If one Paget's sarcoma is found, the entire body should be surveyed as the tumor often arises in more than one site.
The exact pathology of lesions arising from Paget's disease need to be confirmed by biopsy. The tumour cells of Paget's sarcoma are derived from osteoblasts, have large, pleomorphic nuclei, are poorly differentiated and produce osteoid. The tumour can have different appearances depending on the matrix produced: bone (osteoblastic), fibrous (fibroblastic), cartilage (chondroblastic) or blood vessels (telangiectatic). Periosteal and juxtacortical sarcomas do not arise from Paget's disease.
Treatment for Paget's sarcoma depends on the tumour stage and the general status of the patient, and can vary from wide resection and chemotherapy to palliative radiation for pain control.
