Paget disease

• related: Endocrine

Symptoms and Diagnosis

Symptoms

• most commonly present as asymptomatic elderly pt with high alk phos or incidental finding on imaging
• Sx: focal area of bone pain, deformity, fracture
• Atypical: spinal cord, cranial nerve compression from expansion of bone

Diagnosis

• thickening of cortical bone
• coarsened trabecular markings
• distortion and expansion of involved bone
• Biopsy is rarely needed
• Alk phos elevated Alkaline phosphatase may be elevated in other conditions, including vitamin D deficiency, other metabolic bone disease (such as osteomalacia), or recent fracture. Therefore, all patients with suspected Paget disease of bone require assessment of serum calcium, 25-hydroxyvitamin D, and a whole-body radionuclide bone scan.

Management

• indication for treatment: bone pain, risk of fracture, deformity, neurologic problem, elevated alk phos
• check alk phos first to establish baseline
• Bisphophonate primary treatment
  • one time IV zoledronic acid 5mg
• Monitor annual alk phos levels

Uworld

This patient likely has Paget disease of bone (PDB), a common condition in older adults that is due to increased bone turnover. His head computed tomography (CT) scan shows a thickened calvarium with an inhomogeneous bone density or "cotton wool" appearance that is typical of this condition. Most patients with PDB are asymptomatic, and diagnosis is made incidentally on radiographic findings or abnormal laboratory studies. The next step in management of this patient is to obtain calcium and alkaline phosphatase levels; patients with PDB have an elevated alkaline phosphatase and a normal calcium level. If necessary, the elevated alkaline phosphatase of PDB may be differentiated from hepatobiliary disease by measuring the bone-specific fraction. Patients with PDB should also have a radionuclide bone scan to identify other involved sites. Bisphosphonates are the mainstay of treatment for PDB as they reduce bone turnover. Most patients, including those with bone pain or involvement of high-risk locations (such as this patient with skull involvement), should be considered for treatment.

Hearing loss is a common complication of PDB, affecting as many as 37% of patients in one survey. There are likely multiple pathologic mechanisms, including compression of the auditory nerve by bony overgrowth or involvement of the cochlea and/or cochlear capsule itself. Treatment of PDB with calcitonin or bisphosphonate therapy may slow the progression of hearing loss but does not appear to reverse the loss that has already occurred.