Age / Sex : /

Age / Sex : 47/ female

Chief complaint : Lower back pain with both buttock pain for 1 month (Click to enlarge)

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1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to Ja-Young Choi, MD (drchoi01@gmail.com)
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Courtesy : In Sook Lee, MD.
Pusan National University Hospital

Paget's disease

Discussion

Answer: Paget’s disease

Findings:

Conventional radiograph of the pelvis shows typical features of Paget’s disease consisting of radiodense regions in right femoral head and cortical thickening in the proximal portion of the femur. Alterations extend from the femoral head to the mid-diaphyseal region of right femur. The similar finding is also seen in left pelvic bone.
Plain lateral view of the lumbar spine reveals coarsened trabeculae and the increased thickness of the marginal trabeculae in the T12, L5 bodies. Marked accumulation of radionuclide in the left hemipelvis, right proximal femur, several vertebral bodies and left humeral head is noted on bone scintigraphy.
On a sagittal fat-suppressed contrast-enhanced T1-weighted image, axial T1- and T2-weighted images of lumbar spine, coarse or thickened trabeculation appears as regions of low signal intensity in the T12, L5 bodies and spinous processes of T12, L1. Also multiple intertrabecular islands of fat are noted in the L5 body.


Differential Diagnosis:
Bony metastasis
Fibrous dysplasia
Renal osteodystrophy

Diagnosis:
Paget’s disease

Discussion:
Paget’s disease of bone (osteitis deformans) is a condition of uncertain cause that affects approximately 3% of the population over the age of 40 years. It is a process localized to one or several regions of the skeleton, with or without clinical manifestations and slowly progressive. Paget’s disease dominates in middle-aged and elderly persons. Men are affected somewhat more frequently than women. Clinical findings are highly variable. Although of unclear cause, recent evidence suggests a viral etiology, most likely an RNA-type virus related to measles or subacute slcerosing panencephalitis.
The bones of the axial skeleton are typically involved in Paget’s disease, including the pelvis, sacrum, spine, and skull. In the extremities, the femur is affected most often, followed in frequency by the humerus. Polyostotic abnormalities are more frequent than monostotic abnormalities. The skeletal changes reflect an initial stage of intense osteoclastic activity with trabecular resorption, manifesting radiographically as osteolysis and a subsequent stage of disorganized bone formation, leading to mixed osteolytic- osteosclerotic pattern and finally a purely osteosclerotic appearance. The specific characteristics of the radiographic findings reflect the stage of the process but include an axial predominance, a preference for the ends of the long and short tubular bones, bone enlargement, and a coarsened trabecular pattern.
Musculoskeletal complications include osseous deformities, insufficiency fractures, complete fractures, neurologic abnormalities, soft tissue masses, neoplasm, and osteoarthritis. Of the neoplasms, osteosarcoma predominates.
Diffuse increased skeletal radiodensity may be observed in bony metastasis, myelofibrosis, fluorosis, mastocytosis, renal osteodystrophy, fibrous dysplasia, and tuberous sclerosis.
Treatment has been in a state of flux. Currently five classes of drugs are available: bisphosphonates, calcitonin, mithramycin, gallium nitrate, ipriflavone. The efficacy of the treatment is monitored by the clinical response, imaging methods, and serum markers of bone turnover.

References:

1. Resnick D, Kyriakos M, Greenway GD. In: Resnick D, Kransdorf MJ, 3rd ed. Bone and joint imaging. Philadelphia, Pen: Saunders, 2005;576-588
2. Resnick D, Kang HS, Pretterklieber ML. 2nd ed. Internal derangements of joints. Philadelphia, Pen: Saunders, 2007; 428-436
3. Resnick D. Paget disease of bone: current status and a look back to 1943 and earlier. AJR 1988;150:249-256