From Hutchinson to now: a historical glimpse

Challenging diagnosis: unveiling extensive multisystemic sarcoidosis with musculoskeletal involvement through a clinically ambiguous soft tissue mass in the palm

We report about a 33-year-old man who was referred for assessment of a progressively enlarging mass of the palmar hand muscles, serving as the initial indication of extensive multisystemic sarcoidosis with musculoskeletal involvement. The case underscores the diagnostic challenges associated with the indolent course of sarcoidosis, highlighting the need for recognizing seemingly benign symptoms for early detection. Musculoskeletal imaging findings presented in the case stress the importance of considering sarcoidosis in the differential diagnosis of orthopedic cases. This report emphasizes the importance of understanding possible musculoskeletal imaging findings in sarcoidosis, thereby enabling radiologists to effectively guide patient management.

Evaluation and Management of Cardiac Sarcoidosis with Advanced Imaging

A high clinical suspicion in the setting of appropriate history, physical exam, laboratory, and imaging parameters is often required to set the groundwork for diagnosis and management. Echocardiography may show septal thinning, evidence of systolic and diastolic dysfunction, along with impaired global longitudinal strain. Cardiac MRI reveals late gadolinium enhancement along with evidence of myocardial edema and inflammation on T2 weighted imaging and parametric mapping. 18F-FDG PET detects the presence of active inflammation and the presence of scar. Involvement of the right ventricle on MRI or PET confers a high risk for adverse cardiac events and mortality.

Diagnosis of cardiac sarcoidosis: a primer for non-imagers

Sarcoidosis is a multisystem granulomatous disorder that can potentially involve any organ. Cardiac involvement in sarcoidosis has been reported in up to 25% of patients based on autopsy and imaging studies. The gold standard for diagnosing cardiac sarcoidosis is endomyocardial biopsy demonstrating non-caseating granulomas; however, this technique lacks sensitivity due to the patchy nature of myocardial involvement. This, along with the non-specific clinical presentation, renders the diagnosis of cardiac sarcoidosis extremely challenging. Difficulties in obtaining histopathologic diagnosis and the advances in imaging modalities have led to a paradigm shift toward non-invasive imaging in the diagnosis of cardiac sarcoidosis. Advances in cardiac imaging modalities have also allowed unprecedented insights into the prevalence and natural history of cardiac sarcoidosis. This review discusses the role of non-invasive imaging for diagnosis, risk stratification, and monitoring the response to therapies in cardiac sarcoidosis. Echocardiography remains the first-line modality due to widespread availability and affordability. Cardiac magnetic resonance imaging (CMR) can be used to study cardiac structure, function, and most importantly tissue characterization to detect inflammation and fibrosis. Fluoro-deoxy glucose positron emission tomography (FDG PET) is the gold standard for non-invasive detection of cardiac inflammation, and it offers the unique ability to assess response to therapeutic interventions. Hybrid imaging is a promising technique that allows us to combine the unique strengths of CMR and FDG PET. Understanding the advantages and disadvantages of each of these imaging modalities is crucial in order to tailor the diagnostic algorithm and utilize the most appropriate modality for each patient.

Myositis and myopathy of sarcoidosis: A case report

Muscular manifestations of sarcoidosis are commonly found on biopsy but rare on correlated imaging. We present a rare case of a 36-year-old male patient with sarcoid myositis and image findings of active myositis in the lower back and pelvic girdle musculature. This case suggests considering sarcoidosis as a differential diagnosis in the setting of chest findings and new lower back and lower extremity weakness.

Exercise-induced torsades de pointes as an unusual presentation of cardiac sarcoidosis: A case report and review of literature

BACKGROUND

Sarcoidosis is a rare multisystem disease characterized histologically by non-caseating granuloma formation in the affected organ. While cardiac sarcoidosis is found on autopsy in up to 25% of sarcoidosis cases, it is still underdiagnosed and is associated with a poor prognosis. Although the etiology of sarcoidosis remains unclear, an antigen triggered exaggerated immune response has been hypothesized. Early detection and prompt management of cardiac sarcoidosis remains pivotal.

CASE SUMMARY

A 60-year-old female, with pulmonary sarcoidosis in remission, presented to the cardiology outpatient clinic for evaluation of weeks-long dyspnea on moderate exertion (New York Heart Association class II) that was relieved by rest. Submaximal exercise stress test showed multifocal ventricular extrasystoles, followed by a self-limiting torsades de pointes. Cardiac magnetic resonance imaging showed nondilated and normotrophic left ventricle with basoseptal and mid-septal dyskinesis. The magnetic resonance imaging-derived left ventricular ejection fraction was 45%. Delayed enhancement showed patchy transmural fibrosis of the septum and hyperenhancement of the papillary muscles, all in favor of extensive cardiac involvement of sarcoidosis. A double-chamber implantable cardiac defibrillator was implanted, and methylprednisolone (12 mg/d) and methotrexate (12.5 mg/wk) treatment was initiated. Follow-up and implantable cardiac defibrillator interrogation showed episodes of asymptomatic nonsustained ventricular tachycardia and an asymptomatic episode of nonsustained ventricular tachycardia ending by the first antitachycardia pacing run.

CONCLUSION

Along an extensive review of the literature, this unusual case report highlights the importance of early detection of cardiac involvement of sarcoidosis, in order to avoid potential complications and increase survival.

Cardiac magnetic resonance imaging-indeterminate/negative cardiac sarcoidosis revealed by 18F-fluorodeoxyglucose-positron emission tomography: two case reports and a review of the literature

Background

Sarcoidosis is an inflammatory disorder of immune dysregulation characterized by non-caseating granulomas that can affect any organ. Cardiac sarcoidosis is an under-recognized entity that has a heterogeneous presentation and may occur independently or with any severity of systemic disease. Diagnosing cardiac sarcoidosis remains problematic with endomyocardial biopsies associated with a high risk of complications. Several diagnostic algorithms are currently available that rely on histopathology or clinical and radiological measures. The dominant mode of diagnostic imaging to date for cardiac sarcoidosis has been cardiac magnetic resonance imaging with gadolinium enhancement.

Case presentations

We report the cases of two adult patients: case 1, a 50-year-old white man who presented with severe congestive cardiac failure; and case 2, a 37-year-old white woman who presented with complete heart block. Both patients had a background of untreated pulmonary sarcoidosis. Cardiac magnetic resonance imaging did not show evidence of sarcoidosis in either patient and both proceeded to ¹⁸F-fluorodeoxyglucose-positron emission tomography scans that were highly suggestive of cardiac sarcoidosis. Both patients were systemically immunosuppressed with orally administered prednisone and methotrexate and had subsequent improvement by clinical and nuclear medicine imaging measures.

Conclusions

Current consensus guidelines recommend all patients with sarcoidosis undergo screening for occult cardiac disease, with thorough history and examination, electrocardiogram, and transthoracic echocardiogram. If any abnormalities are detected, advanced cardiac imaging should follow. While cardiac magnetic resonance imaging identifies the majority of cardiac sarcoidosis, early disease may not be detected. These cases demonstrate ¹⁸F-fluorodeoxyglucose-positron emission tomography is warranted following an indeterminate or normal cardiac magnetic resonance imaging if clinical suspicion remains high. Unidentified and untreated cardiac sarcoidosis risks significant morbidity and mortality, but early detection can facilitate disease-modifying immunosuppression and cardiac-specific interventions.

Clinical and Biological Insights from the University of California San Francisco Prospective and Longitudinal Cohort

INTRODUCTION

Sarcoidosis is a systemic inflammatory disease characterized by non-necrotizing granulomas in involved organs, most commonly the lung. Description of patient characteristics in the Western United States is limited. Furthermore, blood-based measures that relate to clinical sarcoidosis phenotypes are lacking. We present an analysis of a prospective, longitudinal sarcoidosis cohort at a Northern Californian academic medical center.

METHODS

We enrolled 126 sarcoidosis subjects and 64 healthy controls and recorded baseline demographic and clinical characteristics. We used regression models to identify factors independently associated with pulmonary physiology. We tested whether blood transcript levels at study entry could relate to longitudinal changes in pulmonary physiology.

RESULTS

White, non-Hispanics composed ~70% of subjects. Hispanics and Blacks had a diagnostic biopsy at an age ~7 years younger than whites. Obstructive, but not restrictive, physiology characterized Scadding Stage IV patients. Subjects reporting use of immunosuppression had worse FEV1%p, FVC%p, and DLCO%p compared to subjects never treated, regardless of Scadding stage. We defined sarcoidosis disease activity by a drop in pulmonary function over 36 months and found that subjects meeting this definition had significant repression of blood gene transcripts related to T cell receptor signaling pathways, referred to as the "TCR factor."

CONCLUSION

Obstructive pulmonary physiology defined Stage IV patients which were mostly white, non-Hispanics. Genes comprising the composite gene expression score, TCR factor, may represent a blood-derived measure of T-cell activity and an indirect measure of active sarcoidosis inflammation. Validation of this measure could translate into individualized treatment for sarcoidosis patients.

Cardiac sarcoidosis-state of the art review

Sarcoidosis is a multi-system inflammatory disorder of unknown etiology resulting in formation of non-caseating granulomas. Cardiac involvement-which is associated with worse prognosis-has been detected in approximately 25% of individuals based on autopsy or cardiac imaging studies. Nevertheless, the diagnosis of cardiac sarcoidosis is challenging due to the low yield of endomyocardial biopsy, and the limited accuracy of various clinical criteria. Thus, no gold standard diagnostic criterion exists. This review will summarize the pathophysiology, diagnosis, and treatment of cardiac sarcoidosis with a focus on advanced cardiovascular imaging, We review the evidence to support a role for cardiac magnetic resonance (CMR) imaging in the initial evaluation of selected patients with suspected cardiac sarcoidosis, with cardiac positron emission tomography (PET) as an alternative or complementary initial diagnostic test in a subgroup of patients in whom CMR may be contra-indicated or when CMR is negative with continued clinical concern for myocardial inflammation. In addition to the diagnostic value of these tests, CMR and PET are also useful in identifying patients who have higher risk of adverse events such as ventricular tachycardia or death, in whom preventive therapies such as defibrillators should be more strongly considered. Although no randomized controlled trials for treatment of cardiac sarcoidosis exist, immunosuppressive therapy is often used. We review emerging evidence regarding the use of cardiac PET to identify and quantity the amount of myocardial inflammation as well as to guide the use of immunotherapy. Future studies are needed to determine the benefit of imaging guided therapies aimed at improving patient outcomes.

Sarcoidosis: Role of non-tuberculosis mycobacteria and Mycobacterium tuberculosis

Sarcoidosis is a granulomatous inflammatory disease that is induced by unknown antigen(s) in a genetically susceptible host. Although the direct link between Mycobacterium tuberculosis (MTB) infection and sarcoidosis can be excluded on the basis of current knowledge, non-infectious mechanisms may explain the causative role of mycobacterial antigens. Ever since sarcoidosis was first described, its relationship with tuberculosis (TB) has been under-investigated. Whereas some researchers consider sarcoidosis and TB as two examples of the same disease process, others have rejected mycobacteria as playing any causative role in sarcoidosis. Whether they are linked causally or not, clinical evidence makes a differential diagnosis between the two conditions very challenging, particularly in countries with high burden of TB. The present study analyzes the relationship between sarcoidosis and TB and its implications in clinical practice. The coincidence of TB and sarcoidosis and the higher incidence of mycobacterial DNA in biological samples of sarcoid patients have been reported by many authors. In addition, new evidence of a similarity in MTB phenotype in sarcoidosis is provided. Overall, these observations suggest that TB and sarcoidosis may not only share the same etiology, but may even be different aspects of one disease.

Evidence for mycobacteria in sarcoidosis

Despite its recognition as a distinct granulomatous disease for over a century, the etiology of sarcoidosis remains to be defined. Since the early 1900s, infectious agents have been suspected in causing sarcoidosis. For much of this time, mycobacteria were considered a likely culprit, yet until recently, the supporting evidence has been tenuous at best. In this review, we evaluate the reported association between mycobacteria and sarcoidosis. Historically, mycobacterial infection has been investigated using histologic stains, cultures of lesional tissue or blood, and identification of bacterial nucleic acids or bacterial antigens. More recently, advances in biochemical, molecular, and immunological methods have produced a more rigorous analysis of the antigenic drivers of sarcoidosis. The result of these efforts indicates that mycobacterial products likely play a role in at least a subset of sarcoidosis cases. This information, coupled with a better understanding of genetic susceptibility to this complex disease, has therapeutic implications.

Clinical advances in the diagnosis and therapy of the interstitial lung diseases

The last century experienced remarkable advances in the classification, diagnosis, and understanding of the pathogenesis of the interstitial lung diseases. Technological advances, particularly physiologic testing, lung imaging studies, bronchoalveolar lavage, surgical lung biopsy, and histopathologic assessment, improved our understanding of these entities. In particular, the advent of high-resolution computed tomography, the narrowed pathologic definition of usual interstitial pneumonia, and recognition of the prognostic importance of separating usual interstitial pneumonia from other idiopathic interstitial pneumonia patterns have profoundly changed the approach to these processes. Most recently, genetic medicine, the use of new technologies (e.g., microarrays, mass spectroscopic analysis of proteins, and laser capture microdissection), and the development of animal models have had a major impact on understanding the pathogenesis and potential molecular targets for interfering with fibrogenesis. This article highlights some of the advances and changes in clinical practice that took place in the management of patients with interstitial lung diseases over the last century.