Psoriasis, bone and bowel: a comprehensive review and new insights

Psoriasis is a chronic immune-mediated disorder affecting about 2% of the population worldwide which is associated with significant morbidity. The disease usually presents as raised, well-demarcated erythematous plaques with adherent silvery scales. Psoriasis can appear at any age but it has two peaks occurring at 15–20 and 55–60 years of age. It affects males and females equally. Despite the multitude of investigations about psoriasis and even development of drugs with satisfactory results, its pathogenesis is not fully understood yet and its course is unpredictable. Various environmental triggers, e.g., obesity, stress and drugs may induce disease in genetically susceptible patients. Although psoriasis was considered primarily as a disease of the skin, more investigations have been revealed its systemic nature. Psoriatic arthritis (PsA) may complicate up to one-third of cases of psoriasis vulgaris (PV). Also, the association between psoriasis and a variety of other immune-mediated disorders such as inflammatory bowel disease (IBD) and celiac disease (CD) has been confirmed in various studies. Moreover, a growing body of evidences indicates that psoriasis shares some common histological and phenotypical properties with the spectrum of osteoimmunological diseases such as Paget’s disease of bone (PDB). Thus, exploring the common molecular and genetic mechanisms underlying psoriasis and related disorders is of paramount importance for better elucidating disease pathogenesis and designing more targeted treatments.

[Imaging Findings of Spinal Metastases with Differential Diagnosis: Focusing on Solitary Spinal Lesion in Older Patients]

If a solitary spinal lesion is found in an older patient, bone metastasis can be primarily considered as the diagnosis. Bone metastasis can occur anywhere, but it mostly occurs in the vertebral body and may sometimes show typical imaging findings, presenting as a single lesion. Therefore, differentiating it from other lesions that mimic bone metastases can be challenging, potentially leading to delayed diagnosis and initiation of primary cancer treatment. This review provides an overview of imaging findings and clinical guidelines for bone metastases and discusses its differences from other diseases that can occur as solitary spinal lesions in older patients.

Analysis of muscle magnetic resonance imaging of a large cohort of patient with VCP-mediated disease reveals characteristic features useful for diagnosis

BACKGROUND

The diagnosis of patients with mutations in the VCP gene can be complicated due to their broad phenotypic spectrum including myopathy, motor neuron disease and peripheral neuropathy. Muscle MRI guides the diagnosis in neuromuscular diseases (NMDs); however, comprehensive muscle MRI features for VCP patients have not been reported so far.

METHODS

We collected muscle MRIs of 80 of the 255 patients who participated in the "VCP International Study" and reviewed the T1-weighted (T1w) and short tau inversion recovery (STIR) sequences. We identified a series of potential diagnostic MRI based characteristics useful for the diagnosis of VCP disease and validated them in 1089 MRIs from patients with other genetically confirmed NMDs.

RESULTS

Fat replacement of at least one muscle was identified in all symptomatic patients. The most common finding was the existence of patchy areas of fat replacement. Although there was a wide variability of muscles affected, we observed a common pattern characterized by the involvement of periscapular, paraspinal, gluteal and quadriceps muscles. STIR signal was enhanced in 67% of the patients, either in the muscle itself or in the surrounding fascia. We identified 10 diagnostic characteristics based on the pattern identified that allowed us to distinguish VCP disease from other neuromuscular diseases with high accuracy.

CONCLUSIONS

Patients with mutations in the VCP gene had common features on muscle MRI that are helpful for diagnosis purposes, including the presence of patchy fat replacement and a prominent involvement of the periscapular, paraspinal, abdominal and thigh muscles.

Extraprostatic incidental findings on prostate mpMRI: A pictorial review from the ESUR junior network

The role of multiparametric MRI (mpMRI) in prostate cancer setting is increasingly consolidated and, as a result, its usage in clinical practice is in exponential growth. However, beyond the prostate gland, several key structures are included in the field of view of mpMRI scans. Consequently, various extra-prostatic incidental findings (IFs) belonging to different anatomical systems can be accidentally recognized. Therefore, it is mandatory for a radiologist to be familiar with the wide range of pathologies potentially encountered, to guide management and avoid patient anxiety and costs due to additional work-up prompted by clinically insignificant extra-prostatic findings. With this pictorial review, we aim to illustrate a wide range of IFs that can be detected when performing mpMRI of the prostate, focusing on their imaging characteristics, differential diagnosis, and clinical relevance. Additionally, we propose the CheckDEEP, the Checklist for DEtection of ExtraProstatic findings, to be used for a thorough evaluation of target areas within each anatomical system.

Paget's Disease or Densifying Metastasis: How to Sort It Out

Although the prevalence of Paget's disease has decreased over the past 20 years, incidental discovery on imaging is not unusual. The challenge is to establish the diagnosis, especially in unusual forms that may be mistaken for metastases. This review describes the typical imaging features of Paget's disease and some rare presentations that may be more difficult to recognize.

Cardiac Transthyretin Amyloidosis With Coincident Paget's Disease: A Case Report

Cardiac amyloidosis is a condition that results from the accumulation of amyloid proteins in the extracellular matrix of the myocardium. The diagnosis of this disease was challenging as it lacked distinct clinical symptoms and required a biopsy to confirm amyloid deposition. However, there is increasing evidence of non-invasive diagnostic criteria for cardiac amyloidosis, especially for the transthyretin (TTR) type. We report a case of a patient with both cardiac transthyretin amyloidosis (ATTR) and Paget's disease, and we highlight the various radiological features of these two conditions using hybrid imaging techniques. In addition, we discuss the diagnostic imaging characteristics of ATTR cardiac amyloidosis.

A Case Report of Progressive Paget Disease Mimicking a Malignancy: A Second Episode 21 Years Later

Paget osteosarcoma is a rare but serious complication of Paget disease requiring immediate management before further malignant transformation. This case report examines the progression of a previously reported case of Paget disease with atypical pseudotumor manifestation, mimicking osteosarcoma over a 21-year time lapse. After presenting with substantial pain and elevated alkaline phosphatase levels, imaging proved extensive bony expansion of the lesion with high-grade trabecular and cortical thickening and extraosseous soft-tissue extension, prompting the need for biopsy to rule out Paget sarcoma. The atypical features of the pseudotumor's development helps distinguish key radiographic and clinical criteria for malignant development.

Musculoskeletal pitfalls in 68Ga-PSMA PET/CT

Prostate-specific membrane antigen (PSMA) is a transmembrane protein expressed in normal prostate cells and overexpressed in prostate cancer. Consequently, it is an important tool in the evaluation of prostate cancer, including the staging of high-risk patients and the assessment of biochemical recurrence. Despite the "specific" designation, benign musculoskeletal conditions, such as fractures, osteodegenerative changes, and fibrous dysplasia, can also show PSMA uptake, which can lead to misinterpretation of the imaging findings. Therefore, radiologists must be aware of these potential pitfalls, understand their causes, and fully analyze their morphologic features on unfused computed tomography (CT) and magnetic resonance imaging scans to correctly interpret the examination. In this pictorial essay, we review the basic characteristics of the 68Ga-PSMA positron-emission tomography/CT (PET/CT) radiotracer, discuss potential causes of false-positive findings on 68Ga-PSMA PET/CT in the musculoskeletal system, and illustrate the corresponding imaging findings.

AS. Clival and Paraclival Lesions: A Pictorial Review

The clivus is a midline anatomical structure in the central skull base. It is affected by a wide range of non-neoplastic, benign and malignant pathologies, some of which typically affect the clivus because of its strategic location and embryological origins. Clival lesions may often be asymptomatic with occasional complaints like headache or cranial neuropathy in few. Cross-sectional imaging techniques, namely, computed tomographic scan and magnetic resonance imaging, thus, play a key role in approximating to the final diagnosis and estimating the disease extent. In this article, we highlight the important imaging features of various clival and paraclival pathologies to facilitate effective diagnosis, therapeutic planning, and management.

Benign incidental do-not-touch bone lesions

Benign bone lesions may occasionally be incidentally detected on radiographs and are also increasingly found on CT or MRI performed for other clinical indications. Although mostly asymptomatic or associated with minor symptoms, these lesions may simulate true pathological lesions, causing problems in diagnosis. For instance, asymptomatic benign bone lesions can be misinterpreted as metastasis when incidentally encountered in a patient with known cancer. Recognising these entities as "do-not-touch" lesions helps avoid unnecessary further investigation or harmful intervention. In this review, we highlight three groups of bone incidentalomas found in adults, namely: osteolytic lesions, osteoblastic lesions, and bone protuberances. We aim to review the key imaging features of selected common and less common conditions in these three groups, so as to help radiologists confidently identify these benign do-not-touch lesions and to distinguish them from more sinister pathological lesions.

Regulation of human ZNF687, a gene associated with Paget's disease of bone

Mutations in Zinc finger 687 (ZNF687) were associated with Paget's disease of bone (PDB), a disease characterized by increased bone resorption and excessive bone formation. It was suggested that ZNF687 plays a role in bone differentiation and development. However, the mechanisms involved in ZNF687 regulation remain unknown. This study aimed to obtain novel knowledge regarding ZNF687 transcriptional and epigenetic regulation. Through in silico analysis, we hypothesized three ZNF687 promoter regions located upstream exon 1 A, 1B, and 1 C and denominated promoter regions 1, 2, and 3, respectively. Their functionality was confirmed by luciferase activity assays and positive/negative regulatory regions were identified using promoter deletions constructs. In silico analysis revealed a high density of CpG islands in these promoter regions and in vitro methylation suppressed promoters' activity. Using bioinformatic approaches, bone-associated transcription factor binding sites containing CpG dinucleotides were identified, including those for NFκB, PU.1, DLX5, and SOX9. By co-transfection in HEK293 and hFOB cells, we found that DLX5 specifically activated ZNF687 promoter region 1, and its methylation impaired DLX5-driven promoter stimulation. NFκB repressed and activated promoter regions 1 and 2, respectively, and these activities were affected by methylation. PU.1 induced ZNF687 promoter region 1 which was affected by methylation. SOX9 differentially regulated ZNF687 promoters in HEK293 and hFOB cells that were impaired after methylation. In conclusion, this study provides novel insights into ZNF687 regulation by demonstrating that NFκB, PU.1, DLX5, and SOX9 are regulators of ZNF687 promoters, and DNA methylation influences their activity. The contribution of the dysregulation of these mechanisms in PDB should be further elucidated.

Non-neoplastic pathologies mimicking sarcoma - Experience from a tertiary referral centre multidisciplinary team

OBJECTIVE

Distinguishing non-neoplastic tumour-mimicking pathologies from bone and soft tissue tumours is one of the fundamental aims of a tertiary centre sarcoma multidisciplinary team (MDT) service. In this study, we aim to analyse the incidence of non-neoplastic lesions referred to a tertiary referral service as suspected sarcoma, and to analyse the spectrum of conditions comprising these tumour-mimicking pathologies.

MATERIALS AND METHODS

We conducted a retrospective observational study compiling the biopsy-proven non-neoplastic outcomes of suspected sarcoma cases referred to our MDT in the last year. We identified all referrals made to our service between 1st January 2020 and 31st December 2020 and compiled their histological diagnoses.

RESULTS

A total of 976 new cases were referred to our MDT as suspected sarcoma in one year. Of these referrals, 8.6% (84/976) received a biopsy-proven outcome of non-neoplastic pathology. These non-neoplastic outcomes were categorised into the following types of pathology: 32.1% vascular, 31.0% inflammatory, 14.3% traumatic, 6.0% degenerative, 6.0% idiopathic, 4.8% infective, 3.6% metabolic, 1.2% autoimmune, and 1.2% genetic.

CONCLUSION

A significant proportion of pathologies referred to a tertiary centre sarcoma MDT are non-neoplastic in nature. These lesions are made up of a range of pathologies, with vascular and inflammatory conditions being the most common. Our study, the first of its kind, offers clinicians an insight into tumour-mimicking pathologies encountered by a tertiary centre.

Artroplastia total de cadera en paciente con enfermedad de Paget: presentación de un caso

Introducción: La enfermedad de Paget es un trastorno metabólico de etiología desconocida, secundario a un incremento en la función de los osteoclastos y la consecuente respuesta de los osteoblastos a la formación exagerada de hueso. Compromete con mayor frecuencia el fémur proximal y, a menudo, se diagnostica incidentalmente. Se presenta el caso de una mujer con antecedente de enfermedad de Paget y pseudoartrosis de cadera izquierda, con indicaciones de prótesis total de cadera izquierda y un episodio único de luxación, sin complicaciones posteriores y una adecuada evolución. Conclusión: El manejo quirúrgico en casos de fractura de cadera permite restablecer la marcha y mejorar la calidad de vida de los pacientes con enfermedad de Paget. A pesar de ser una patología que dificulta el manejo de los pacientes, la enfermedad de Paget no es una contraindicación para la artroplastia total de cadera y permite mejorar el dolor y recuperar la funcionalidad

Updates on Paget's Disease of Bone

Paget's disease of the bone is a prevalent bone disease characterized by disorganized bone remodeling; however, it is comparatively uncommon in East Asian countries, including China, Japan, and Korea. The exact cause still remains unknown. In genetically susceptible individuals, environmental triggers such as paramyxoviral infections are likely to cause the disease. Increased osteoclast activity results in increased bone resorption, which attracts osteoblasts and generates new bone matrix. Fast bone resorption and formation lead to the development of disorganized bone tissue. Increasing serum alkaline phosphatase or unique radiographic lesions may serve as the diagnostic indicators. Common symptoms include bone pain, bowing of the long bones, an enlarged skull, and hearing loss. The diagnosis is frequently confirmed by radiographic and nuclear scintigraphy of the bone. Further, bisphosphonates such as zoledronic acid and pamidronate are effective for its treatment. Moreover, biochemical monitoring is superior to the symptoms as a recurrence indicator. This article discusses the updates of Paget's disease of bone with a clinical case.

Incidental osseous lesions on chest CT: an algorithmic approach for radiologists

Numerous osseous findings are commonly discovered incidentally at chest CTs in daily practice. A broad spectrum of these findings ranges from benign and do not touch lesions to ominous conditions requiring further imaging evaluation and/or intervention. Interpretation of these incidental musculoskeletal findings may constitute a diagnostic challenge to radiologists. This review provides a systematic, algorithmic approach to common osseous lesions on chest CT based on imaging findings with recommendations for proper next step management.

Imaging of Metabolic Bone Diseases: The Spine View, Part I

Metabolic bone diseases comprise a wide spectrum. Of them, osteoporosis is the most frequent and the most commonly found in the spine, with a high impact on health care systems and on morbidity due to vertebral fractures (VFs).This article discusses state-of-the-art techniques on the imaging of metabolic bone diseases in the spine, from the well-established methods to the latest improvements, recent developments, and future perspectives.We review the classical features of involvement of metabolic conditions involving the spine. Then we analyze the different imaging techniques for the diagnosis, characterization, and monitoring of metabolic bone disease: dual-energy X-ray absorptiometry (DXA) and DXA-based fracture risk assessment applications or indexes, such as the geometric parameters, Bone Strain Index, and Trabecular Bone Score; quantitative computed tomography; and magnetic resonance and ultrasonography-based techniques, such as radiofrequency echographic multi spectrometry. We also describe the current possibilities of imaging to guide the treatment of VFs secondary to metabolic bone disease.

Sclerosis of the clavicle––A challenging diagnosis

Condensing osteitis of the clavicle is a rare benign disease described as an increase in bone density at the medial end of the clavicle. Its clinical and radiographic presentation can frequently be equivocal and tissue sampling is necessary for diagnostic confirmation. Here we present the case of a 29-year-old female with condensing osteitis of the right medical clavicle, who remained undiagnosed for many years despite obtaining imaging studies and undergoing an initial biopsy. This disease presents oftentimes a challenging diagnosis due to its imaging features overlapping with many benign and malignant bone lesions. A qualified multidisciplinary team with expertise in rare bone conditions becomes oftentimes essential to arrive at an accurate diagnosis.

A Review of Posteromedial Lesions of the Chest Wall: What Should a Chest Radiologist Know?

A heterogeneous group of tumors can affect the posteromedial chest wall. They form diverse groups of benign and malignant (primary or secondary) pathologies that can arise from different chest wall structures, i.e., fat, muscular, vascular, osseous, or neurogenic tissues. Chest radiography is very nonspecific for the characterization of chest wall lesions. The modality of choice for the initial assessment of the chest wall lesions is computed tomography (CT). More advanced cross-sectional modalities such as magnetic resonance imaging (MRI) and positron emission tomography (PET) with fluorodeoxyglucose are usually used for further characterization, staging, treatment response, and assessment of recurrence. A systematic approach based on age, clinical history, and radiologic findings is required for correct diagnosis. It is essential for radiologists to be familiar with the spectrum of lesions that might affect the posteromedial chest wall and their characteristic imaging features. Although the imaging findings of these tumors can be nonspecific, cross-sectional imaging helps to limit the differential diagnosis and determine the further diagnostic investigation (e.g., image-guided biopsy). Specific imaging findings, e.g., location, mineralization, enhancement pattern, and local invasion, occasionally allow a particular diagnosis. This article reviews the posteromedial chest wall anatomy and different pathologies. We provide a combination of location and imaging features of each pathology. We will also explore the role of imaging and its strengths and limitations for diagnosing posteromedial chest wall lesions.

An AI-based prediction model for drug-drug interactions in osteoporosis and Paget's diseases from SMILES

Referring to common skeletal-related diseases, osteoporosis and Paget's are two of the most frequently found diseases in the elderly. Nowadays, the combination of multiple drugs is the optimal therapy to decelerate osteoporosis and Paget's pathologic process, which contains various underlying adverse effects due to drug-drug interactions (DDIs). Artificial intelligence (AI) has the potential to evaluate the interaction, pharmacodynamics, and possible side effects between drugs. In this research, we created an AI-based machine-learning model to predict the outcomes of interactions between drugs used for osteoporosis and Paget's treatment, furthermore, to mitigate cost and time in implementing the best combination of medications in clinical practice. Our dataset was collected from the DrugBank database, and we then extracted a variety of chemical features from the simplified molecular-input line-entry system (SMILES) of defined drug pairs that interact with each other. Finally, machine-learning algorithms have been implemented to learn the extracted features. Our stack ensemble model from Random Forest and XGBoost reached an average accuracy of 74% in predicting DDIs. It was superior to individual models and previous methods in most measurement metrics. This study showed the potential of AI models in predicting DDIs of Osteoporosis-Paget's disease in particular, and other diseases in general.

Challenges in the Interpretation of MRI Examinations Without Radiographic Correlation: Pearls and Pitfalls to Avoid

As physics introduces more complex and seemingly thorough techniques to evaluate patient symptoms, cross-sectional imaging, especially magnetic resonance imaging (MRI), seems like the modality of choice to best help patients. However, musculoskeletal radiology (MSK) requires not just the excellent soft-tissue contrast provided by MRI but also an evaluation of the aggressiveness of a lesion, a detailed evaluation of osseous anatomy or distribution of disease, and a way to easily identify calcifications and gas in soft tissue in order to make the correct diagnosis. This article will demonstrate, through numerous cases, the importance of radiographs in the full characterization of MSK-related pathology. It will focus on imaging pearls and pitfalls to avoid when radiographs are not available and discuss the findings that can be expected if comparison radiographs were available.

An update on imaging of Paget's sarcoma

Paget's sarcoma is a rare and particularly aggressive tumour arising within pagetic bone, affecting approximately 1% of patients with Paget's disease during the course of their disease. Most of these tumours are osteosarcomas, but the age profile, skeletal distribution and clinical outcomes differ considerably from conventional osteosarcoma. In this review, we outline the clinical, radiographic/CT, scintigraphic and magnetic resonance imaging features of Paget's sarcoma. We also review the neoplastic and non-neoplastic mimics of Paget's sarcoma that should be considered in the differential diagnosis when encountering an aggressive lesion within pagetic bone.

Imaging Spectrum of Calvarial Abnormalities

Calvarial abnormalities are usually discovered incidentally on radiologic studies or less commonly manifest with symptoms. This narrative review describes the imaging spectrum of the abnormal calvaria. The extent, multiplicity, and other imaging features of calvarial abnormalities can be combined with the clinical information to establish a final diagnosis or at least narrow the differential considerations. Prior trauma (congenital depression, leptomeningeal cysts, posttraumatic osteolysis), surgical intervention (flap osteonecrosis and burr holes), infection, and inflammatory processes (sarcoidosis) can result in focal bone loss, which may also be seen with idiopathic disorders without (bilateral parietal thinning and Gorham disease) or with (Parry-Romberg syndrome) atrophy of the overlying soft tissues. Anatomic variants (arachnoid granulations, venous lakes, parietal foramina) and certain congenital lesions (epidermoid and dermoid cysts, atretic encephalocele, sinus pericranii, and aplasia cutis congenita) manifest as solitary lytic lesions. Other congenital entities (lacunar skull and dysplasia) display a diffuse pattern of skull involvement. Several benign and malignant primary bone tumors involve the calvaria and manifest as lytic, sclerotic, mixed lytic and sclerotic, or thinning lesions, whereas multifocal disease is mainly due to hematologic or secondary malignancies. Metabolic disorders such as rickets, hyperparathyroidism, renal osteodystrophy, acromegaly, and Paget disease involve the calvaria in a more diffuse pattern. Online supplemental material is available for this article. ^©RSNA, 2021.

Radiologic Imaging of Metabolic and Endocrine Disorders as They Affect the Hand and Wrist

Metabolic and endocrine disorders have systemic effects on the musculoskeletal system, frequently producing characteristic changes in the hand and wrist. Radiographs historically played an instrumental role in the diagnostic pathway of many of these disorders, but the myriad of endocrinologic tests readily available to current clinicians may suggest their importance has lessened. We disagree. Recognition of these often subtle features can avoid the expense and psychological impact of an inappropriate diagnostic work-up, as well as expediting the diagnosis of potentially unsuspected disease. The metabolic and endocrine disorders discussed here are based on the distinctive changes produced around the hand and wrist.

Primary Tumors of the Sacrum: Imaging Findings

The diagnosis of sacral neoplasms is often delayed because they tend to remain clinically silent for a long time. Imaging is useful at all stages of managing sacral bone tumors: from the detection of the neoplasm to the long-term follow-up. Radiographs are recommended as the modality of choice to begin the imaging workup of a patient with known or suspected sacral pathology. More sensitive examinations such as computerized tomography (CT), magnetic resonance (MRI), or scintigraphy are often necessary. The morphological features of the lesions on CT and MRI help to orientate the diagnosis. Although some imaging characteristics are helpful to limit the differential diagnosis, an imaging-guided biopsy is often ultimately required to establish a specific diagnosis. Imaging is of paramount importance even in the long-term follow-up in order to assess any residual tumor when surgical resection is incomplete, to assess the efficacy of adjuvant chemotherapy and radiotherapy, and to detect recurrence.

Sclerotic bone lesions caused by non-infectious and non-neoplastic diseases: a review of the imaging and clinicopathologic findings

Bone sclerosis is a focal, multifocal, or diffuse increase in the density of the bone matrix on radiographs or computed tomography (CT) imaging. This radiological finding can be caused by a broad spectrum of diseases, such as congenital and developmental disorders, depositional disorders, and metabolic diseases. The differential diagnosis can be effectively narrowed by an astute radiologist in the light of the clinical picture and typical findings on imaging. Some of these lesions are rare and have been described as case reports and series in the literature. This article aims to collate the clinical-radiologic findings of non-infectious and non-neoplastic causes of bone sclerosis with relevant imaging illustrations.

"Skull on Fire": Monostotic Paget Disease of the Skull Bone

An 81-year-old woman was evaluated for a stroke. CT showed no intracranial abnormalities but diffuse patchy aspect of the neurocranium. An MRI and F-NA PET/CT were performed to differentiate between metastases, Paget disease, hyperostosis frontalis interna, and primary malignancy. MRI yielded no additional findings. F-NA PET/CT showed diffusely increased uptake in the skull and 4 spots with intense uptake. No other suspicious skeletal foci were seen elsewhere. Low-dose CT showed no sign of malignancy elsewhere. Image findings together with elevated serum alkaline phosphatase levels, slightly increased calcium levels, and normal phosphorus levels were interpreted as pathognomic for monostotic Paget.

Misdiagnosis of Paget's Disease of Bone in a Congenital Generalized Lipodystrophy Patient: Case Report

Paget's disease of bone (PDB) is a common skeleton disorder in which the diagnosis is suggested by radiological analyses. Congenital generalized lipodystrophy (CGL) is a rare, but a radiologic differential diagnosis of Paget's disease. Patients present total or almost total lack of subcutaneous adipose tissue, leptin deficiency, and precocious ectopic lipid accumulation, which lead to intense insulin resistance, poorly controlled diabetes mellitus, and hypertriglyceridemia. CGL subtypes 1 and 2 present sclerosis and osteolytic lesions that can resemble "pagetic" lesions. The clinical correlation is, therefore, essential. We report a CGL patient with bone lesions in which the radiographic findings led to a misdiagnosis of PDB. This case report brings awareness to CGL, a life-threating condition. Its early recognition is essential to avoid clinical complications and premature death. Therefore, it is important to consider CGL as PDB's differential diagnosis, especially in countries with high prevalence of this rare disease, such as Brazil.

Fibrous Dysplasia, Paget's Disease of Bone, and Other Uncommon Sclerotic Bone Lesions of the Craniofacial Bones

Imaging studies of the brain, head and neck, sinuses, and dental computed tomography are among the most frequently performed procedures in radiologic departments. Systematic evaluation in the bone window may reveal common and uncommon sclerotic osseous abnormalities of the craniofacial skeleton.Most of these findings are incidental and unrelated to the initial clinical indications. Sporadically symptoms may arise due to lesional mass effect with compression on adjacent structures and neuroforaminal encroachment, resulting in proptosis, vision, or hearing loss. Other symptoms include craniofacial deformity, mandibular occlusion deformity, and local pain.This article reviews the most common disorders characterized by an increased bone density involving the craniofacial bones including fibrous dysplasia, Paget's disease of bone, meningioma with associated hyperostosis, and osteoma. Finally, typical examples of rarer sclerosing bone dysplasias are discussed as well.Emphasis is placed on imaging features and the differential diagnosis.

Chronic femoral diaphyseal osteomyelitis with radiographs initially concerning for Paget disease of the bone

Chronic osteomyelitis can be difficult to diagnose given its similar radiographic appearance to other lesions. This case report describes a 48-year-old woman, who presented with left thigh pain and on radiography a large disorganized sclerotic lesion involving nearly the entire femoral diaphysis, concerning for Paget disease or malignancy. Biopsy suggested chronic osteomyelitis but did not identify a causative organism. Treatment with antibiotics led to resolution of pain and improvement of biochemical markers. This case exemplifies the role of radiographic imaging in the diagnosis of chronic osteomyelitis and the possible utility of antibiotics for culture-negative chronic osteomyelitis. We review imaging modalities for the diagnosis of chronic osteomyelitis and Paget disease.

Paget disease of bone in an elderly patient with chronic renal disease and weight loss: A case report

RATIONALE

Asymptomatic Paget disease of bone (PDB) is mostly diagnosed by accidental finding of osteolytic lesion on the plain film. However, in elderly patient with chronic renal insufficiency and weight loss, it is crucial to differentiate PDB from metabolic and metastatic bone diseases for further treatment and better outcome.

PATIENT CONCERNS

An 80-year-old man with chronic kidney disease presented to our emergency department due to fever with chillness for a day, while the abdominal fullness, anorexia, and weight loss had been noted for 3 months. Mixed osteoblastic and lytic changes in the pelvic bone were accidentally found on the abdominal plain film.

DIAGNOSIS

The patient was diagnosed as asymptomatic PDB and urinary tract infection of Pseudomonas aeruginosa.

INTERVENTIONS AND OUTCOME

The patient received 7 days intravenous and followed by 7 days oral antibiotic treatment, which lead to clinical improvement of his urinary tract infection. No pharmacological treatment was initiated for the asymptomatic and localized PDB. The patient was discharged under stable condition afterward.

LESSONS

In patients with mixed osteolytic and blastic lesions, the differential diagnoses include metabolic and metastatic bone disease. Thorough understanding of the morphology of the bone lesions in high risk patient, not only helps to make differential diagnosis, but it also leads to precise treatment and better outcome.

Systemic Changes Affecting the Morphology of Calvarial Bone

Plastic surgeons are frequently consulted to evaluate concerns about a patient's skull. Imaging studies often reveal abnormalities in bone morphology, from increased porosity to sclerotic changes. While focal findings imply a benign or malignant neoplasm, the etiology of more diffuse findings can be more varied, making the correct diagnosis challenging. The present review summarizes the differential diagnosis of osseous lesions of the calvarium that affect the bone and contribute to changes seen on imaging studies.

Radiological manifestations of renal osteodystrophy in the orofacial region: a case report and literature review

Renal osteodystrophy (ROD) is a metabolic skeletal pathology that frequently affects the orofacial region and presents with characteristic radiological manifestations. This paper reports a case of ROD causing diffused orofacial bone alterations in a female patient with end-stage chronic kidney disease. The radiological features on panoramic, posteroanterior and lateral skull and computed tomography radiographs are described for this case. Previous reports in the literature are reviewed and discussed with a focus on radiological characteristics and differential diagnoses.

Paget's Disease of Bone: Diagnosis and Treatment

Paget's disease of bone is a common bone disorder characterized by disorganized bone remodeling. The most likely etiology is a slow paramyxoviral infection in genetically susceptible individuals; however, the exact cause is unknown. Enhanced bone resorption due to an increased activity of osteoclasts recruits numerous osteoblasts to resorption sites, with large quantities of new bone matrix produced as a result. The accelerated bone resorption and formation are not as closely coupled as in a healthy bone; a disorganized bone tissue is formed. Many patients are asymptomatic; rising serum alkaline phosphatase or incidental finding of characteristic radiographic lesions are often the only diagnostic clues. Common clinical manifestations include bone pain, bowing of long bones, enlarged skull, and hearing loss. An elevated serum alkaline phosphatase level correlates with the disease activity. The diagnosis is confirmed by characteristic radiographic findings and by nuclear scintigraphy of the bone (the most sensitive test). Bisphosphonates, such as zoledronic acid, pamidronate, alendronate, and risedronate, are the mainstay of treatment. Patients who do not tolerate bisphosphonates can be treated with calcitonin.

A rare case of Paget's disease affecting the cervical spine

We present the case of a 75-year-old man with a rapidly progressive cervical myelopathy on a background of a 3-year history of neck pain and a severely degenerative cervical spine. The patient developed progressive myelopathy over a six-month period and suffered from worsening kyphosis. Suspicion of an underlying oncological process prompted transfer to our tertiary referral unit. Biopsy was consistent for Paget's disease, an extremely rare diagnosis of the cervical spine. Magnetic resonance imaging revealed cord compression between C4 and C6 with associated cord signal change indicative of myelopathy. A three-level corpectomy and posterior instrumented fusion was performed. There was significant blood loss (3.5l) intraoperatively, consistent with a diagnosis of Paget's disease of the bone. Cell salvage was used, as was neuromonitoring for both the anterior and posterior part of the procedure. Postoperatively, neurological function improved slightly and the patient required community neurorehabilitation to allow independent living.

Radiological review of skull lesions

Abstract

Calvarial lesions are often asymptomatic and are usually discovered incidentally during computed tomography or magnetic resonance imaging of the brain. Calvarial lesions can be benign or malignant. Although the majority of skull lesions are benign, it is important to be familiar with their imaging characteristics and to recognise those with malignant features where more aggressive management is needed. Clinical information such as the age of the patient, as well as the patient’s history is fundamental in making the correct diagnosis. In this article, we will review the imaging features of both common and uncommon calvarial lesions, as well as mimics of these lesions found in clinical practice.

Teaching Points

• Skull lesions are usually discovered incidentally; they can be benign or malignant.

• Metastases are the most frequent cause of skull lesions.

• Metastatic lesions are most commonly due to breast cancer in adults and neuroblastoma in children.

• Multiple myeloma presents as the classic “punched out” lytic lesions on radiographs.

• Eosinophilic granuloma is an osteolytic lesion with bevelled edges.

Nuclear Medicine Imaging in the Dentomaxillofacial Region

Nuclear medicine studies evaluate physiology on a molecular level providing earlier detection of lesions before morphologic change is evident. ^99mTc-MDP and ¹⁸F-fluoride bone scans detect osteomyelitis earlier than radiographs and computed tomography (CT); aid in diagnosis of temporomandibular joint disorder; and evaluate activity of condylar hyperplasia, extent of Paget disease, and viability of bone grafts. ¹⁸F-FDG PET/CT distinguish between soft tissue and bone infections and diagnose osteomyelitis complicated by fracture or surgery. FDG PET is more accurate than CT alone and has a major role in staging, restaging, and assessing response to therapy for head and neck malignancies and in detecting sequelae of therapy.

Craniofacial Manifestations of Systemic Disorders: CT and MR Imaging Findings and Imaging Approach

Many systemic diseases or conditions can affect the maxillofacial bones; however, they are often overlooked or incidentally found at routine brain or head and neck imaging performed for other reasons. Early identification of some conditions may significantly affect patient care and alter outcomes. Early recognition of nonneoplastic hematologic disorders, such as thalassemia and sickle cell disease, may help initiate earlier treatment and prevent serious complications. The management of neoplastic diseases such as lymphoma, leukemia, or Langerhans cell histiocytosis may be different if diagnosed early, and metastases to the maxillofacial bones may be the first manifestation of an otherwise occult neoplasm. Endocrinologic and metabolic disorders also may manifest with maxillofacial conditions. Earlier recognition of osteoporosis may alter treatment and prevent complications such as insufficiency fractures, and identification of acromegaly may lead to surgical treatment if there is an underlying growth hormone-producing adenoma. Bone dysplasias sometimes are associated with skull base foraminal narrowing and subsequent involvement of the cranial nerves. Inflammatory processes such as rheumatoid arthritis and sarcoidosis may affect the maxillofacial bones, skull base, and temporomandibular joints. Radiologists should be familiar with the maxillofacial computed tomographic and magnetic resonance imaging findings of common systemic disorders because these may be the first manifestations of an otherwise unrevealed systemic process with potential for serious complications. Online supplemental material is available for this article. ^©RSNA, 2018.

Clinical and Microstructural Findings in Paget Disease of the Entire Mandible

Paget disease of bone (PDB) is a chronic progressive bone disorder characterized by localized increased bone turnover and focal areas of woven bone formation. Although skull involvement is common, PDB very rarely affects the mandible. This report describes the clinical and histologic findings in a 75-year-old patient with PDB involving the mandible. Microstructural analyses showed an altered quality of the bone microstructure and calcium depletion of the affected bone. Differential diagnosis of PDB affecting the mandible is discussed.

Incidental finding of a monostotic form of Paget Disease of the scapula in a lung cancer patient

Paget Disease of the bone is a metabolic disorder which leads to a profound alteration of the bone's architecture. It may be asymptomatic and, since its radiological features mimic those of bone metastases, may present a diagnostic dilemma during the evaluation of a cancer patient. We illustrate an uncommon monostotic form of the disease, affecting solely the scapula, diagnosed during the staging of a lung cancer patient.

Benign Bone Conditions That May Be FDG-avid and Mimic Malignancy

Positron emission tomography with the radiotracer ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) plays an important role in the evaluation of bone pathology. However, FDG is not a cancer-specific agent, and knowledge of the differential diagnosis of benign FDG-avid bone alterations that may resemble malignancy is important for correct patient management, including the avoidance of unnecessary additional invasive tests such as bone biopsy. This review summarizes and illustrates the spectrum of benign bone conditions that may be FDG-avid and mimic malignancy, including osteomyelitis, bone lesions due to benign systemic diseases (Brown tumor, Erdheim-Chester disease, Gaucher disease, gout and other types of arthritis, Langerhans cell histiocytosis, and sarcoidosis), benign primary bone lesions (bone cysts, chondroblastoma, chondromyxoid fibroma, desmoplastic fibroma, enchondroma, giant cell tumor and granuloma, hemangioma, nonossifying fibroma, and osteoid osteoma and osteoblastoma), and a group of miscellaneous benign bone conditions (post bone marrow biopsy or harvest status, bone marrow hyperplasia, fibrous dysplasia, fractures, osteonecrosis, Paget disease of bone, particle disease, and Schmorl nodes). Several ancillary clinical and imaging findings may be helpful in discriminating benign from malignant FDG-avid bone lesions. However, this distinction is sometimes difficult or even impossible, and tissue acquisition will be required to establish the final diagnosis.

Clinical and Genetic Advances in Paget's Disease of Bone: a Review

Paget’s disease of bone (PDB) is the second most common metabolic bone disorder, after osteoporosis. It is characterised by focal areas of increased and disorganised bone turnover, coupled with increased bone formation. This disease usually appears in the late stages of life, being slightly more frequent in men than in women. It has been reported worldwide, but primarily affects individuals of British descent. Majority of PDB patients are asymptomatic, but clinical manifestations include pain, bone deformity and complications, like pathological fractures and deafness. The causes of the disease are poorly understood and it is considered as a complex trait, combining genetic predisposition with environmental factors. Linkage analysis identified SQSTM1, at chromosome 5q35, as directly related to the disease. A number of mutations in this gene have been reported, pP392L being the most common variant among different populations. Most of these variants affect the ubiquitin-associated (UBA) domain of the protein, which is involved in autophagy processes. Genome-wide association studies enlarged the number of loci associated with PDB, and further fine-mapping studies, combined with functional analysis, identified OPTN and RIN3 as causal genes for Paget’s disease. A combination of risk alleles identified by genome-wide association studies led to the development of a score to predict disease severity, which could improve the management of the disease. Further studies need to be conducted to elucidate other important aspects of the trait, such as its focal nature and the epidemiological changes found in some populations. In this review, we summarize the clinical characteristics of the disease and the latest genetic advances to identify susceptibility genes. We also list current available treatments and prospective options.

Renal Cell Carcinoma Metastasized to Pagetic Bone

Paget's disease of the bone, historically known as osteitis deformans, is an uncommon disease typically affecting individuals of European descent. Patients with Paget's disease of the bone are at increased risk for primary bone neoplasms, particularly osteosarcoma. Many cases of metastatic disease to pagetic bone have been reported. However, renal cell carcinoma metastasized to pagetic bone is extremely rare. A 94-year-old male presented to the emergency department complaining of abdominal pain. A computed tomography scan of the abdomen demonstrated a large mass in the right kidney compatible with renal cell carcinoma. The patient was also noted to have Paget's disease of the pelvic bones and sacrum. Within the pagetic bone of the sacrum, there was an enhancing mass compatible with renal cell carcinoma. A subsequent biopsy of the renal lesion confirmed renal cell carcinoma. Paget's disease of the bone places the patient at an increased risk for bone neoplasms. The most commonly reported sites for malignant transformation are the femur, pelvis, and humerus. In cases of malignant transformation, osteosarcoma is the most common diagnosis. Breast, lung, and prostate carcinomas are the most common to metastasize to pagetic bone. Renal cell carcinoma associated with Paget's disease of the bone is very rare, with only one prior reported case. Malignancy in Paget's disease of the bone is uncommon with metastatic disease to pagetic bone being extremely rare. We report a patient diagnosed with concomitant renal cell carcinoma and metastatic disease within Paget's disease of the sacrum. Further research is needed to assess the true incidence of renal cell carcinoma associated with pagetic bone.

The myriad of diseases that present with polyostotic bone lesions

Many diseases result in polyostotic bone lesions including benign entities, benign entities with malignant potential, intermediate entities, and malignant entities. Imaging plays a key role in identifying complications of these disorders, most importantly malignant transformation of a benign lesion. The most common polyostotic bone lesions are reviewed and examples of malignant transformation are highlighted.

Tumours and tumour mimics in the olecranon

Lesions in the olecranon are rare and may be identified during the investigation of a clinically suspected abnormality or as an incidental finding. This review describes the spectrum of tumours and tumour-like lesions that can involve the olecranon and illustrates the radiographic, CT, and MRI appearances that may facilitate diagnosis. A variety of pathological processes affecting the olecranon are presented and discussed including the epidemiology and imaging features.