BONE PATHOLOGY CASE STUDIES

CASE 4 - Paget's disease of bone

Clinical History:

A 55 year old caucasian male has noted increasing low back pain, and left proximal leg pain, particularly after sitting for extended periods of time. A radiograph shows coarsened bony trabeculae of the left intertrochanteric region. There is also prominent sclerosis of the left sacroiliac joint. A CT scan of the left proximal femur (Slide 4.1) shows trabecular and cortical thickening without cortical break through or a soft tissue mass. A bone biopsy of the proximal left femur was performed.
  1. What is the diagnosis?

    2. This is Paget's disease of bone. The mosaic pattern of the bony trabeculae is diagnostic.

  2. In whom and at what sites does this lesion occur?

    3. Males are affected more often than females. Paget's disease of bone tends to occur in older caucasian persons after the age of 50, and approaches a 10% incidence in the very old, but it is asymptomatic in up to 90% of cases. If it involves a single site, it is "monostotic". If several sites are involved, it is "polyostotic". Pelvis, femur, and skull are often affected. The classic history is given by the man who says his hat size is increasing.

  3. What is the clinical course of this disease?

    4. Early, there is osteolysis. This is followed by the classic osteoblastic-osteolytic phase (as in this case) with bone deformity. Finally, there is a sclerotic phase. There is a 1% risk for development of a sarcoma. In fact, this man also had a sarcoma of the right ilium (the most common site for a Paget's sarcoma).