Case Author(s): M.Roarke, M.D., F. Vanwagenen, M.D., J. Wallis, M.D. , 10/6/95 . Rating: #D3, #Q5

Diagnosis: Diffuse Paget's Disease

Brief history:

Painful palpable mass in the right anterior iliac region.


Anterior and posterior images from whole body delayed bone scintigraphy.

View main image(bs) in a separate image viewer

View second image(xr). AP radiograph of the right tibia.

View third image(xr). AP pelvis radiograph.

View fourth image(mr). Pelvis MRI.

Full history/Diagnosis is available below

Diagnosis: Diffuse Paget's Disease

Full history:

45-year old black woman with known neurofibromatosis 1 and history of Pagetıs disease diagnosed three years ago. She now presents with a painful palpable mass in the right anterior iliac region. The alkaline-phosphatase measured 400. This examination was requested to evaluate for evidence of scintigraphic abnormality associated with the palpable mass as well as to confirm the diagnosis of Pagetıs disease. There is no history of metabolic bone disease, metastatic disease, primary malignancy or fibrous dysplasia.


21.8 mCi Tc-99m MDP i.v.


There are multiple areas of markedly increased tracer uptake throughout the skeleton; findings at several sites, such as the tibiae and right hemipelvis (most evident on the posterior image in the peri-acetabular region), suggest Pagetıs disease. However, many of the sites would be difficult to distinguish from diffuse metastatic disease. Plain radiographs of the areas of abnormality on scintigraphy reveal the characteristic findings in Pagetıs disease. In the spine and pelvis, sclerosis, coarsening of trabeculae, and slight enlargement of bone are all findings consistent with the sclerotic phase of Pagetıs disease. In the tibiae, an advancing front of lytic change is present radiographically, giving the so-called ³blade of grass² appearance of the lytic phase of Pagetıs disease. The pelvic MRI demonstrated multiple masses which were hyperintense on T-2 weighted sequences and which enhanced with i.v. gadolinium administration.


Pagetıs disease is common, occurring in 3.5% of the population greater than 40 years old and in 10% of the population greater than 80 years old. The onset of the disease in the population less than 40 years old is uncommon. The etiologic agent is likely a paramyxovirus. The phases of Pagetıs disease include osteoclastic, osteoblastic/clastic, and osteosclerotic or quiescent phases. Malignant transformation represents a fourth phase. 85% of cases are polyostotic. Clinical features include pain, fractures, nerve compression, skeletal deformities, and osteoarthritis. Laboratory analysis reveals elevated alkaline-phosphatase and urinary hydroxyproline. Pagetıs disease is associated with sarcomatous transformation, giant cell tumors, plasma cell myeloma, and metastases. In this case, the right iliac soft tissue mass demonstrated on magnetic resonance imaging examination was biopsied and proven to represent a giant cell tumor of the tendon sheath rather than a malignancy such as a sarcoma.

References: Resnick, Niyawma. Diagnosis of Bone and Joint Disorders, 3rd edition.

Major teaching point(s):

Comparison with plain radiographs of scintigraphically abnormal regions is frequently necessary for diagnosis.

Differential Diagnosis List

The differential diagnosis includes metastatic disease, Paget's disease, and polyostotic fibrous dysplasia.

ACR Codes and Keywords:

References and General Discussion of Bone Scintigraphy (Anatomic field:Skeletal System, Category:Neoplasm, Neoplastic-like condition)

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Case number: bs040

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