Paget's disease of bone: diagnosis and treatment update

Paget's Disease. A Case Report

Paget's disease (PD) is a common focal progressive osteometabolic disorder characterised by a disturbance in bone modelling and remodelling, because of an increase in osteoblastic and osteoclastic activity. It is a condition of unknown aetiology affecting approximately 3% of the population over 40 years of age and, approximately 10% of those over the age of 85 years. It is most common in Northern Europe and Australia and is rare in Asia and Africa. We describe the case of a 71-year-old man diagnosed with PD confined to the sacrum. After laboratory test, an imaging study with radiography, scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI) was performed disclosing findings compatible with Paget's disease in middle pathologic phase. The diagnosis was confirmed at biopsy. The structural modification of the sacrum with spongiosa rarefaction, thickening of bone and intact bone cortical, confirmed by CT, are tipical of an intermediate phase of PD. This was also supported by signal MRI changes showing substitution of the red by the fat medulla, visualized by FS sequences. Once the treatment for the bone disease was established, the patient no longer complained of pain. Special attention should be paid to male and elderly patients with pain in the lumbar spine because of the potential risk cancer development (21). The radiologist must be attentive to the possible presentations and complications of PD, even in uncommon sites, trying whenever possible to correlate the radiological features with the patient's clinical symptoms.

Radiological features of Paget disease of bone associated with VCP myopathy

OBJECTIVE

Mutations in the Valosin-containing protein (VCP) gene cause a unique disorder characterized by classic Paget disease of bone (PDB), inclusion body myopathy, and frontotemporal dementia (IBMPFD). Our objective was to analyze the radiographic features of PDB associated with VCP mutations since there is a dearth of literature on the PDB component of VCP disease.

MATERIALS AND METHODS

Radiographic bone surveys were examined in 23 individuals with VCP mutation and compared with their unaffected relatives. Laboratory testing relevant for VCP disease was performed in all individuals.

RESULTS

Of the 17 affected individuals with clinical manifestations of VCP disease, 16 of whom had myopathy, radiographic analysis revealed classic PDB in 11 individuals (65%). The mean age of diagnosis for myopathy was 43.8 years and for PDB was 38.1 years of age. Radiological evidence of PDB was seen in one individual (16%) amongst six clinically asymptomatic VCP mutation carriers. Alkaline phosphatase was a useful marker for diagnosing PDB in VCP disease.

CONCLUSIONS

Radiographic findings of classic PDB are seen in 52% of individuals carrying VCP mutations at a significantly younger age than conventional PDB. Screening for PDB is warranted in at-risk individuals because of the benefit of early treatment with the new powerful bisphosphonates that hold the potential for prevention of disease.

Prosthodontic treatment of a patient with bisphosphonate-induced osteonecrosis of the jaw using a removable dental prosthesis with a heat-polymerized resilient liner: a clinical report

Bisphosphonate-induced osteonecrosis of the jaws (BONJ) is reported frequently in patients receiving oral or intravenous bisphosphonates. To minimize potential complications, dental treatment must be performed with care. There are invasive and noninvasive treatment options for patients with active BONJ or a history of this complication. This clinical report describes the prosthodontic treatment of a patient who developed BONJ after receiving intravenous bisphosphonates (pamidronate). Because of the recurrent incidence of BONJ, noninvasive prosthetic therapy with telescopic overdentures and a heat-polymerized resilient liner was provided. After 2 years, there were no biological or technical complications.

Increased resorptive activity and accompanying morphological alterations in osteoclasts derived from the oim/oim mouse model of osteogenesis imperfecta

The current study addresses whether alterations in osteoclasts (OCs) derived from oim/oim mice, an established model of moderate-to-severe OI, are present. Bone marrow cells from oim/oim and wildtype (+/+) mice were cultured on bone slices in the presence of MCSF and RANKL and evaluated at days 0, 1, 2, 4, and 7. OCs were identified by tartrate-resistant acid phosphatase (TRAP) staining, and bone slice resorption pits were analyzed by reflection microscopy. Flow cytometry was used to examine CD51 (integrin alphaV) and CD61 (integrin beta3) markers. Confocal microscopy was used to assess changes in OC morphology and resorption. There was no difference between the OC precursors of the two genotypes in expression of CD51 and CD61 markers. At day 2, the bone slices seeded with oim/oim cells had a greater percentage of mononuclear cells associated with resorption pits compared to +/+ bone slices. At day 4, the diameter and area of oim/oim OCs were larger compared to the +/+ OCs, and the number of nuclei per OC was also greater for the oim/oim group. At day 7, the oim/oim OCs contained more F-actin rings compared to the +/+ OCs, and the number of OCs in the oim/oim group was greater compared to the +/+ group. The resorbed area of bone slices for the oim/oim group was also greater compared to the +/+ group at day 7. In conclusion, oim/oim mononuclear resorbing cells and OCs showed cellular changes and greater resorptive activity compared to +/+ cells, features that likely contribute to dysregulated bone remodeling in OI.

Paget's disease: a case in point

Paget's disease (PD) is the second most common bone disease in older adults, yet many clinicians are unfamiliar with it and may not consider it a diagnostic possibility. This article uses a case study to introduce the topic of Paget's disease. The definition, incidence, and etiology of PD is addressed. Normal bone physiology is defined in contrast to the pathophysiology of PD. Patient history, laboratory tests, and imaging studies are summarized with regard to the diagnosis of PD. Treatment options are discussed including pharmacologic management and prognosis. The article concludes with implications for nursing care of the patient with PD.

General medicine and surgery for dental practitioners. Part 8: Musculoskeletal system

Disorders of the musculoskeletal system may impact on dental management in diverse ways. Diseases of the bones may have a direct influence on treatment and joint disorders can also cause difficulties. Cervical spine involvement may lead to poor neck extension causing difficulties in providing dental treatment under local anaesthesia or allowing the provision of a safe general anaesthetic. Muscular disorders may mitigate against safe general anaesthesia. As with all medical disorders a thorough history can help to prevent many of the possible problems which may occur secondary to musculoskeletal diseases.

Two cases of monostotic Paget's disease: effects of bisphosphonate

We report two cases of monostotic Paget's disease which were effectively treated with bisphosphonate. Case 1 was a 60-year-old female. Medical examination revealed high alkaline phosphatase (ALP) levels making her visit our clinic. Hematological examination showed high levels of ALP isozyme 3 and bone metabolism markers, and bone scintigraphy demonstrated strong accumulation of 99mTc on the skull. With the diagnosis of monostotic Paget's disease of the skull, treatment with bisphosphonate (etidronate) was started. The response to etidronate was good and after 12 weeks of treatment, the ALP levels decreased to about 26% of the levels before treatment, without the appearance of any symptoms or lesion development. One year and three months later, ALP increased again, and etidronate administration was resumed. However, four years after the diagnosis of the disease, etidronate became ineffective and oral administration of alendronate, a stronger bisphosphonate, was started at 5 mg/day. The patient responded favorably to the bisphosphonate and is still under observation. Case 2 was a 71-year-old female. High ALP levels were found during the follow-up of type 2 diabetes, and the case was diagnosed as monostotic Paget's disease of the pelvis based on bone metabolism markers and bone scintigraphy. Etidronate treatment at 200 mg/day resulted in the improvement of bone metabolism markers and bone scintigraphy findings. When she died of colon cancer twelve months later, with no marked progress of the Paget's disease of bone observed clinically.

Mathematical model predicts a critical role for osteoclast autocrine regulation in the control of bone remodeling

Bone remodeling occurs asynchronously at multiple sites in the adult skeleton and involves resorption by osteoclasts, followed by formation of new bone by osteoblasts. Disruptions in bone remodeling contribute to the pathogenesis of disorders such as osteoporosis, osteoarthritis, and Paget's disease. Interactions among cells of osteoblast and osteoclast lineages are critical in the regulation of bone remodeling. We constructed a mathematical model of autocrine and paracrine interactions among osteoblasts and osteoclasts that allowed us to calculate cell population dynamics and changes in bone mass at a discrete site of bone remodeling. The model predicted different modes of dynamic behavior: a single remodeling cycle in response to an external stimulus, a series of internally regulated cycles of bone remodeling, or unstable behavior similar to pathological bone remodeling in Paget's disease. Parametric analysis demonstrated that the mode of dynamic behavior in the system depends strongly on the regulation of osteoclasts by autocrine factors, such as transforming growth factor beta. Moreover, simulations demonstrated that nonlinear dynamics of the system may explain the differing effects of immunosuppressants on bone remodeling in vitro and in vivo. In conclusion, the mathematical model revealed that interactions among osteoblasts and osteoclasts result in complex, nonlinear system behavior, which cannot be deduced from studies of each cell type alone. The model will be useful in future studies assessing the impact of cytokines, growth factors, and potential therapies on the overall process of remodeling in normal bone and in pathological conditions such as osteoporosis and Paget's disease.

Symptomatic and Scintigraphic Improvement after Intravenous Pamidronate Treatment of Paget’s Disease of Bone in Patients with Normal Serum Alkaline Phosphatase Levels

OBJECTIVE

To describe three patients with symptomatic Paget's disease of bone who presented with normal levels of serum alkaline phosphatase.

METHODS

We present three cases of Paget's disease of bone and chronicle the laboratory, scintigraphic, and clinical findings relative to treatment with intravenously administered pamidronate.

RESULTS

Although measurement of serum total alkaline phosphatase usually provides a general indication of bone turnover in Paget's disease, about 15% of patients present with normal serum alkaline phosphatase levels. Nonetheless, these patients may have active Paget's disease when assessed with bone scintigraphy or urinary markers of bone resorption. All three study patients had xray findings characteristic of Paget's disease of bone, increased uptake of radiotracer material on bone scans, and elevated levels of urinary markers of bone resorption but normal alkaline phosphatase levels. They were treated with intravenously administered pamidronate, 60 mg once weekly for 2 to 3 consecutive weeks. After treatment, the serum alkaline phosphatase level decreased by 19 to 36%, markers of bone resorption normalized, bone scans showed improvement, and bone pain resolved.

CONCLUSION

Pagetic activity in bone and related clinical manifestations may be present in the setting of a normal serum alkaline phosphatase level. Appropriate therapy should not be withheld because of the normal alkaline phosphatase.

From the archives of the AFIP. Radiologic spectrum of Paget disease of bone and its complications with pathologic correlation

Paget disease of bone is a common disorder affecting approximately 3%-4% of the population over 40 years of age. The pathologic abnormality in Paget disease is excessive and abnormal remodeling of bone. Three pathologic phases have been described: the lytic phase (incipient-active), in which osteoclasts predominate; the mixed phase (active), in which osteoblasts cause repair superimposed on the resorption; and the blastic phase (late-inactive) in which osteoblasts predominate. Radiographic appearance of Paget disease reflects these pathologic changes and is often characteristic. Initially, there is osteolysis, particularly affecting the skull (osteoporosis circumscripta) and subchondral long bones, with subsequent development of trabecular and cortical thickening and enlargement of bone in the mixed phase of the disease. Finally, areas of sclerosis may develop in the blastic phase. Frequent sites of involvement include the skull (25%-65% of cases), spine (30%-75%), pelvis (30%-75%), and proximal long bones (25%-30%). Bone scintigraphy typically demonstrates marked increased uptake of radionuclide in all phases of Paget disease. Computed tomography and magnetic resonance imaging often show changes similar to those seen radiographically in noncomplicated Paget disease with maintenance of yellow marrow. Complications of Paget disease include the effects of osseous weakening (deformity and fracture), arthritis, neurologic symptoms, and neoplastic involvement. Sarcomatous transformation is the most feared complication, occurring in approximately 1% of cases, and is seen on images as focal bone destruction extending through the cortex with an associated soft-tissue mass. Recognition of the radiologic spectrum of the appearances of Paget disease usually allows prospective diagnosis and differentiation of its associated complications, which helps guide therapy and improve patient management.

Bilateral enophthalmos associated with paget disease of the skull: a case report

PURPOSE

To describe a case of familial Paget disease of bone associated with bilateral enophthalmos and mild exposure keratopathy.

METHODS

Case report and literature review.

RESULTS

A 71-year-old woman with familial Paget disease of bone had a long history of "receding eyes," headaches, and moderately dry eyes. She had bilateral enophthalmos with mild exposure keratopathy. Radiologic and endocrinologic investigation confirmed Paget disease of bone affecting the skull.

CONCLUSIONS

Enophthalmos in association with Paget disease of bone is rare and is likely to result from differential expansion of the cranium compared with the orbital bones.