A review of the musculoskeletal manifestations of sarcoidosis

Non-negligible ultrasonographic findings in sarcoid myositis: A case series and literature review

Sarcoid myositis is a rare and often debilitating extrapulmonary manifestation of sarcoidosis that can be difficult to recognize without a prior sarcoidosis diagnosis. Sarcoidosis with muscle nodules or masses as the first symptom is the least common form, occurring in approximately 0.5%-2.3% of cases. This article presents four middle-aged female patients who initially sought medical attention for a lower limb mass. Ultrasound examinations revealed consistent characteristic changes indicative of myositis. All patients underwent ultrasound-guided muscle biopsy and were diagnosed with sarcoidosis. Therefore, ultrasonography plays a pivotal role as the primary diagnostic tool for the early detection of sarcoid myositis.

[Position paper of the Austrian Society for Rheumatology and the Austrian Society for Pneumology on the diagnosis and treatment of sarcoidosis 2024]

In many cases sarcoidosis is a multisystemic disease that requires interdisciplinary medical cooperation in the diagnostics, treatment and medical care during follow-up. Due to the often chronic course, it is of utmost importance to include patients with their priorities and wishes at an early stage and extensively in disease management and to establish a shared decision making whenever possible. In the process of writing this joint position paper, the expert group on interstitial and orphan lung diseases of the Austrian Society for Pulmonology and the working group on rheumatological lung disorders of the Austrian Society for Rheumatology and Rehabilitation sought to include patient advocacy groups as well as experts for rare organ manifestations of sarcoidosis. This position paper is not only meant to reflect current scientific and clinical standards but should also focus the national expertise and by networking and exchange to be a first step to strengthen cooperation between stakeholders to ultimately improve care for patients with sarcoidosis.

Rare and common manifestation of musculoskeletal and sinonasal sarcoidosis: A case report

Sarcoidosis is a systemic granulomatous disease that can affect multiple organ systems. Although many sarcoidosis patients are asymptomatic, the variable clinical progression of symptomatic patients and the nonspecific presentation make diagnosis difficult in certain cases. Musculoskeletal and sinonasal involvement of sarcoidosis are uncommon manifestations, and they are often only seen in patients with widespread disease. Diagnosis of osseous sarcoidosis, sarcoid arthropathy, and sarcoid rhinosinusitis are typically based on a combination of clinical history, radiological findings, and pathologic specimens. Although there are classic image findings, such as lacelike honeycomb appearance of small bones of the hands or hilar/mediastinal lymphadenopathy, sole reliance on image findings for the diagnosis of sarcoidosis is unreasonable as many findings are nonspecific. However, failure to include sarcoidosis in the differential diagnosis often leads to a delay in recognition of musculoskeletal or sinonasal involvement and results in ineffective treatment plan. Even in patients with biopsy-proven sarcoidosis, some image findings in isolation that may represent granulomatous infiltrates are disregarded as nonspecific without raising the possibility of sarcoidosis due to its rare occurrence. Here we discuss a case of multisystemic sarcoidosis in a 42-year-old female with a constellation of classic and rare findings of biopsy-proven sarcoidosis.

The Role of MRI in Differentiating Demyelinating and Inflammatory (not Infectious) Myelopathies

Demyelinating and inflammatory myelopathies represent a group of diseases with characteristic patterns in neuroimaging and several differential diagnoses. The main imaging patterns of demyelinating myelopathies (multiple sclerosis, neuromyelitis optica spectrum disorder, acute disseminated encephalomyelitis, and myelin oligodendrocyte glycoprotein antibody-related disorder) and inflammatory myelopathies (systemic lupus erythematosus-myelitis, sarcoidosis-myelitis, Sjögren-myelitis, and Behçet's-myelitis) will be discussed in this article, highlighting key points to the differential diagnosis.

Symptomatic myopathies in sarcoidosis: disease spectrum and myxovirus resistance protein A expression

OBJECTIVES

Symptomatic myopathy in sarcoidosis patients is not always due to sarcoid myopathy (ScM). We investigated the clinical and pathological spectrum including myxovirus resistance protein A (MxA) expression among sarcoidosis patients.

METHODS

We reviewed the Mayo Clinic database (May 1980-December 2020) to identify sarcoidosis patients with myopathic symptoms and pathological evidence of myopathy.

RESULTS

Among 5885 sarcoidosis patients, 21 had symptomatic myopathy. Eight carried a diagnosis of sarcoidosis 5.5 years (median) prior to myopathy onset. Eleven patients had ScM. The remaining had non-sarcoid myopathies (five IBM, one immune-mediated necrotizing myopathy, one non-specific myositis, two non-specific myopathy and one steroid myopathy). Estimated frequency of IBM is 85 per 100 000 sarcoidosis patients. The following features were associated with non-sarcoid myopathies (P < 0.05): (i) predominant finger flexor and quadriceps weakness, (ii) modified Rankin scale (mRS) >2 at time of diagnosis, (iii) creatine kinase >500 U/l, and (iv) absence of intramuscular granulomas. Sarcoplasmic MxA expression was observed in scattered myofibres in three patients, two of whom were tested for DM-specific autoantibodies and were negative. Immunosuppressive therapy led to improvement in mRS ≥1 in 5/10 ScM, none of the five IBM, and 3/3 remaining patients with non-sarcoid myopathies.

DISCUSSION

Symptomatic myopathy occurred in 0.36% of sarcoidosis. IBM was the second most common cause of myopathies after ScM. Frequency of IBM in sarcoidosis is higher than in the general population. Recognition of features suggestive of alternative aetiologies can guide proper treatment. Our findings of abnormal MxA expression warrant a larger study.

[Sarcoidosis]

Sarcoidosis is the most common granulomatous disease in northern Europe. A distinction is made between acute forms of sarcoidosis and chronic sarcoidosis. Chronic sarcoidosis can affect practically all organs but the lungs are affected in 90-95% of patients. The clinical appearance varies between asymptomatic and oligosymptomatic courses, which are diagnosed more by chance, to courses with acute organ failure. An extensive organ work-up is necessary at the time of the initial diagnosis in order to record the extent of organ involvement and to make appropriate treatment decisions. Asymptomatic courses with purely pulmonary sarcoidosis do not require treatment and can be observed over the course of the disease, whereas courses with extensive organ involvement or organ dysfunction require treatment. The treatment consists primarily of the administration of glucocorticoids. If the effect of the glucocorticoids is insufficient or if there are side effects, various immunosuppressive agents, including biologics can be added.

Ankle and Foot: Focus on Inflammatory Disease

The ankle and foot have numerous bones and complex joints that can be affected by several types of inflammatory arthritis with different patterns and various radiologic signs, depending on the phase of the disease. Involvement of these joints is most frequently seen in peripheral spondyloarthritis and rheumatoid arthritis in adults and juvenile idiopathic arthritis in children. Although radiographs are a mainstay in the diagnostic process, ultrasonography and especially magnetic resonance imaging allow early diagnosis and are crucial diagnostic tools. Some diseases have typical features based on target populations (e.g., adults versus children, men versus women), but others may have overlapping imaging characteristics. We highlight key diagnostic features and describe appropriate investigations to guide clinicians toward the correct diagnosis and provide support during disease monitoring.

Granulomatous myopathy: Sarcoidosis and beyond

Non-necrotizing granulomatous inflammation is a rare but easily recognized histopathological finding in skeletal muscle biopsy. A limited number of diseases are known to be associated with non-necrotizing granulomatous myopathy. Once identified, a careful evaluation for evidence of extramuscular granulomatosis and other signs suggestive of sarcoidosis is warranted as about half of the patients have sarcoid myopathy. In addition, the presence of granulomatous myopathy should trigger a search for clinical and pathological clues of inclusion body myositis (IBM), which accounts for most of the remaining patients and can coexist with sarcoidosis. Recognizing the features of IBM in patients with granulomatous myopathy can potentially spare the patients from unnecessary exposure to immunosuppressive therapies. In patients whose granulomatous myopathy remain unexplained, further investigations should aim at identifying myasthenia gravis and other autoimmune disorders, especially those known to cause granulomatous inflammation in other organs. Laboratory investigations should include acetylcholine receptor, antimitochondrial, antineutrophil cytoplasmic, thyroglobulin, and thyroid peroxidase autoantibodies. In the appropriate clinical context, exposure to immune checkpoint inhibitors and chronic graft-vs-host disease can be causes of granulomatous myopathy. In cases of unexplained granulomatous myopathy, natural killer/T-cell lymphoma should be considered and careful histopathological examination for atypical cells and appropriate immunostaining is crucial. Identifying the etiology of granulomatous myopathy in each patient can guide appropriate treatment.

Elderly sarcoidosis in Japan

OBJECTIVE

The manifestations of sarcoidosis differ by ethnicity and region. However, the few studies that have focused on elderly sarcoidosis are only from Western countries. Therefore, we investigated elderly sarcoidosis in Japan.

METHODS

We retrospectively reviewed the records of adult patients (≥18 years old) who were diagnosed with sarcoidosis from 1 April 2006 to 31 March 2020. The diagnosis was pathologically confirmed in all patients. We compared the clinical features of elderly (diagnosed at ≥65 years old) and non-elderly (diagnosed at <65 years old) patients.

RESULTS

Thirty-five (33%) of 106 patients were elderly. The elderly group had significantly more comorbidities than the non-elderly group (median [range], 1 [0-4] vs. 0 [0-5]). The biopsy site at diagnosis included significantly more extrathoracic sites in the elderly than non-elderly group (57.1% vs. 33.8%). The elderly group had significantly more muscle lesions than the non-elderly group at the time of diagnosis (11.4% vs. 1.4%) and at any time during follow-up (17.1% vs. 1.4%).

CONCLUSION

In Japan, elderly patients with sarcoidosis might have more muscle involvement and comorbidities than younger patients. Because comorbidities might affect the prognosis of elderly sarcoidosis, further study is needed to clarify the effect of comorbidities on elderly sarcoidosis.

Sarcoidosis with musculoskeletal manifestations: systematic review of non-pharmacological and pharmacological treatments

We aimed to summarise effects and use of non-pharmacological and pharmacological treatments for sarcoidosis with musculoskeletal manifestations. We systematically searched the Cochrane Library, Ovid MEDLINE, Embase, CINAHL, AMED, Scopus, clinical.trials.gov, PROSPERO and PEDro for systematic reviews from 2014 to 2022 and for primary studies from date of inception to March 29, 2022, and studies with patients diagnosed with sarcoidosis with musculoskeletal manifestations. Inclusion criteria required that studies reported effects of non-pharmacological and/or pharmacological treatments or number of patients receiving these treatments. Results were reported narratively and in forest plots. Eleven studies were included. No systematic reviews fulfilled our inclusion criteria. None of the included studies had a control group. We found that between 23 and 100% received corticosteroids, 0-100% received NSAIDs, 5-100% received hydroxychloroquine, 12-100% received methotrexate, 0-100% received TNF inhibitors, and 3-4% received azathioprine. Only ten patients in one study had used non-pharmacological treatments, including occupational therapy, chiropractic and acupuncture. There are no controlled studies on treatment effects for patients with sarcoidosis with musculoskeletal manifestations. We found 11 studies reporting use of pharmacological treatments and only one study reporting use of non-pharmacological treatments. Our study identified major research gaps for pharmacological and non-pharmacological treatment in musculoskeletal sarcoidosis and warrant randomised clinical trials for both.

An Atypical Case of Extrapulmonary Sarcoidosis

Sarcoidosis is an idiopathic, inflammatory condition that affects nearly all organs in the body. Lungs are the most frequent and among the earliest sites for detecting it. The most common extrapulmonary manifestations involve the ophthalmic, cardiac, nervous, reticuloendothelial, cutaneous, hepatosplenic, and renal systems. These extrapulmonary manifestations of sarcoid may be misdiagnosed in the absence of the classical pulmonary features, given the high overlap of features with other chronic immunologic diseases. The diagnostic workup to differentiate sarcoid from other similar conditions is extensive, amongst which histology remains a gold standard tool for the diagnosis. Our patient presented with a chronic history of multiple vague complaints including nausea, vomiting, progressive malaise, vision changes, and weight loss. After extensive workup, a diagnosis of sarcoidosis along with multiple rare extrapulmonary involvements was made. The authors highlight essential implications including primary practice goals to avoid misdiagnosis or missed sarcoid diagnoses thus helping improve clinical outcomes in similar populations.

Bone fragility and sarcoidosis: An underestimated relationship

INTRODUCTION

Sarcoidosis is a chronic multisystem inflammatory disease which may affect any organ. Also bone can be involved both directly and indirectly. Data on BMD values and fragility fractures in sarcoidosis patients are few and heterogeneous. This study aimed to characterized the presence of fracture and the relative risk factors in patients with sarcoidosis.

MATERIALS AND METHODS

In this single center cross-sectional study we evaluated 252 sarcoidosis patients (54.7 ± 12.1 years) compared to sex-and age matched healthy controls. We measured BMD at lumbar spine, at femoral neck and at total hip. Moreover, the presence of fragility fractures was collected during osteoporosis visit and all radiological images were examined for the presence of any vertebral fracture according to Genant's method's. Lung function measurements, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, and diffusion capacity for carbon monoxide (DLCO) were assessed.

RESULTS

Bone Mineral Density T-scores were lower in patients affected by sarcoidosis with respect to those obtained in healthy controls, but the difference was statistically significant only for BMD-LS (p < 0.01) and BMD-TH (p < 0.05). Moreover, BMD values at all skeletal sites were significantly associated with DLCO (%) (p < 0.05). The prevalence of fragility fracture was higher in patients with sarcoidosis than in healthy controls (30.6 vs. 12.3%). The patients with ≥3 vertebral fracture had lower values of FVC (%), FEV1 (%), and DLCO (%). Multiple regression analyses showed that BMI was positively associated with fragility fracture, while BMD-TH, DLCO(%) and therapy use was negatively associated.

CONCLUSIONS

Vertebral fractures represent a frequent complication in patients with sarcoidosis. Furthermore, the number of vertebral fractures was linked with a worsening in pulmonary functional tests. Therefore, the degree of severity of the sarcoidosis disease appears to be the main determinant of bone fragility.

[Sarcoidosis as prime example of a granulomatous disease]

Sarcoidosis is the most frequent immunologically related granulomatous disease and can serve as a model for understanding diseases within this category. The evidence on the diagnostics and treatment is so far limited. It is therefore all the more important that two new and significant guidelines on diagnosis and treatment of sarcoidosis were published during the last 2 years. Additionally, there were more new publications, which were considered for this review article. In this context, this review article provides a current update and overview of sarcoidosis. Pathophysiologically, there is an increasing understanding of the complex processes and interactions involved in the inflammatory processes and granuloma formation. The probability of a diagnosis of sarcoidosis is determined by compatible histology, the exclusion of differential diagnoses and if possible evidence of a multiorgan manifestation. The clinical course is variable and ranges from an asymptomatic manifestation to severe life-threatening organ failure. The most frequently affected organ are the lungs. Pulmonary fibrosis is the most severe form and is also decisive for mortality. An increasing focus is on the extrapulmonary organ manifestations, in particular, cardiac, hepatosplenic, gastrointestinal, renal, ocular and neurological involvement. Treatment, which consists primarily of immunosuppression, should be initiated in cases of organ-threatening or quality of life-impairing activity of the disease. Additional organ-specific management must also be evaluated. In cases of organ failure transplantation should be considered. Due to the limited evidence especially for the treatment of multiorgan sarcoidosis, when possible, patients with this disease should be included in clinical trials.

Giant cell myositis associated with metastatic thymoma and granulomatous hypercalcaemia

Giant cell myositis (GCM) is a rare inflammatory myopathy associated with myasthenia gravis and thymoma. Here, we report on a woman in her late 50s with a history of myasthenia gravis, systemic lupus erythematosus and stage IV thymoma with pleural metastases, who presented with proximal weakness, neuromuscular respiratory failure and hypercalcaemia. She was diagnosed with GCM via muscle biopsy and screened for myocarditis but showed no evidence of myocardial involvement. Her hypercalcaemia was consistent with a granulomatous process, likely driven by her GCM. Her strength gradually improved, and her hypercalcaemia did not recur after treatment with high dose steroids, intravenous immune globulin and plasma exchange. Her course was complicated by several opportunistic infections in the setting of her immunosuppression. Despite the high morbidity associated with GCM, she demonstrated clinical improvement after initiating immunosuppressive therapy and continues to be managed in the outpatient setting.

Multiple bone lesions in a patient with fatigue: case report of bone sarcoidosis

Bone sarcoidosis is usually considered a rare manifestation of multisystemic sarcoidosis. With the growing use of more sensitive imaging techniques, such as ¹⁸F-FDG PET, the detection rate of bone involvement seems to be increasing. We describe the case of a woman presenting with fatigue and general malaise having multiple bone lesions on ¹⁸F-FDG PET. A broad range of differential diagnoses was considered, including malignancy, infections, metabolic diseases and primary bone tumours, which may have delayed the diagnosis. Diagnostic work-up eventually led to an anatomopathological diagnosis of bone sarcoidosis. Immunosuppressive therapy is often necessary since sarcoid bone lesions - even asymptomatic - generally appear in more extensive forms of the disease with other organ involvement.

2-deoxy-2[18F]fluoro-D-glucose positron emission tomography-computed tomography in rheumatological diseases

2-deoxy-2[18F]fluoro-D-glucose (FDG) PET-CT has revolutionized oncological imaging. The cellular processes that make cancer cells visible on FDG PET-CT also occur in a number of inflammatory cells. Exploiting this phenomenon has led to a growth of evidence supporting the use of FDG PET-CT in a wide range of infective and inflammatory diseases. Rheumatological diseases can affect multiple sites within the musculoskeletal system alongside multi-organ extra-articular disease manifestations. Inflammation is central to these diseases, making FDG PET-CT a logical choice. In this review article we describe the various applications of FDG PET-CT in rheumatological diseases using illustrative examples to highlight the beneficial role of FDG PET-CT in each case.

Musculoskeletal Manifestations of Sarcoidosis

Since its initial description in the late 19th century, sarcoidosis has been extensively studied. Although the general mechanism of immune activation is known, many details especially in the context of disease associations are still missing. One of such associations is the musculoskeletal complications that are widely variable in terms of presentation and response to treatment. Sarcoidosis can involve the joints leading to acute and, less commonly chronic, arthritis. While acute arthritis is mostly self-resolving in nature, chronic arthritis may lead to deformity and destruction of the joint. Sarcoidosis can also involve the muscles, leading to different pathologies primarily categorized according to the clinical presentation, despite the efforts to find a new classification based on imaging, histological, and clinical findings. The bones can be directly and indirectly affected. Different types of bone lesions have been described, although around half of these patients remain asymptomatic. Osteoporosis, increased risk of fractures, hypercalcemia, and hypercalciuria are examples of the indirect effect of sarcoidosis on the bones, possibly contributed to elevated levels of calcitriol. Nevertheless, sarcoidosis can be associated with small-vessel, medium-vessel, and large vessel vasculitis, although it is frequently difficult to differentiate between the co-existence of a pure vasculitis and sarcoidosis and sarcoid vasculitis.

The Crucial Questions on Synovial Biopsy: When, Why, Who, What, Where, and How?

In the majority of joint diseases, changes in the organization of the synovial architecture appear early. Synovial tissue analysis might provide useful information for the diagnosis, especially in atypical and rare joint disorders, and might have a value in case of undifferentiated inflammatory arthritis, by improving disease classification. After patient selection, it is crucial to address the dialogue between the clinician and the pathologist for adequately handling the sample, allowing identifying histological patterns depending on the clinical suspicion. Moreover, synovial tissue analysis gives insight into disease progression helping patient stratification, by working as an actionable and mechanistic biomarker. Finally, it contributes to an understanding of joint disease pathogenesis holding promise for identifying new synovial biomarkers and developing new therapeutic strategies. All of the indications mentioned above are not so far from being investigated in everyday clinical practice in tertiary referral hospitals, thanks to the great feasibility and safety of old and more recent techniques such as ultrasound-guided needle biopsy and needle arthroscopy. Thus, even in rheumatology clinical practice, pathobiology might be a key component in the management and treatment decision-making process. This review aims to examine some essential and crucial points regarding why, when, where, and how to perform a synovial biopsy in clinical practice and research settings and what information you might expect after a proper patient selection.

Pelvic and Lumbar Pain Revealing Bone Sarcoidosis: A Case Report

A 54-years-old woman suffered from a bilateral pelvic and lumbar pain. She had a systemic investigation shows a diffuse bone lesions. A biopsy of iliac bone was done and revealed sarcoidosis. Bony manifestations of sarcoidosis are rare and challenging to diagnose. Our report shows that MRI with diffusion weighted sequences is a simple and non invasive technique to evaluate bone infiltration. It helps to distinguish inflammatory disease from metastatic lesions and to guide the osseous biopsy. Moreover, fluorodeoxyglucose PET scan, are useful in establishing the extent of damage and measuring disease activity.

Sarcoidosis Presenting as Dorsal Wrist Mass: A Case Report

Patients with sarcoidosis have an indolent course in which the disease is not detected unless seemingly benign symptoms appear. Such was the case in a 42-year-old man who was referred to the orthopedic service for evaluation of a slowly enlarging mass over the left wrist without prior history of trauma. In this article, we will review the symptoms and histopathology of sarcoidosis with a particular focus on orthopedic manifestations of the disease. We believe that clinicians should be aware of these associations so that patients can be diagnosed and treated accordingly.

Skeletal sarcoidosis; an uncommon mimic of metastatic disease

A 66-year-old man with pulmonary sarcoidosis was referred to the urology team for assessment of troublesome lower urinary tract symptoms. An elevated blood serum prostate-specific antigen raised concern for prostate cancer. An MRI of the prostate demonstrated a potentially aggressive prostate lesion, along with low T1 signal skeletal lesions, suggestive of metastatic disease. Subsequent bone scan and MRI whole spine demonstrated further skeletal lesions. In cases of known prostate cancer, sometimes a presumptive diagnosis of skeletal metastases is made without histological diagnosis from the skeletal lesions. However, there were certain factors in this case whereby skeletal biopsy was deemed prudent prior to further therapy. Factors included atypical MRI signal characteristics for metastatic disease, absence of a positive tissue diagnosis from the prostate and the clinical background of sarcoidosis. The biopsy confirmed skeletal sarcoid rather than metastatic disease, thereby avoiding inappropriate and potentially toxic treatment for the patient.

Sarcoidosis: A Clinical Overview from Symptoms to Diagnosis

Sarcoidosis is a multi-system disease of unknown etiology characterized by the formation of granulomas in various organs. It affects people of all ethnic backgrounds and occurs at any time of life but is more frequent in African Americans and Scandinavians and in adults between 30 and 50 years of age. Sarcoidosis can affect any organ with a frequency varying according to ethnicity, sex and age. Intrathoracic involvement occurs in 90% of patients with symmetrical bilateral hilar adenopathy and/or diffuse lung micronodules, mainly along the lymphatic structures which are the most affected system. Among extrapulmonary manifestations, skin lesions, uveitis, liver or splenic involvement, peripheral and abdominal lymphadenopathy and peripheral arthritis are the most frequent with a prevalence of 25-50%. Finally, cardiac and neurological manifestations which can be the initial manifestation of sarcoidosis, as can be bilateral parotitis, nasosinusal or laryngeal signs, hypercalcemia and renal dysfunction, affect less than 10% of patients. The diagnosis is not standardized but is based on three major criteria: a compatible clinical and/or radiological presentation, the histological evidence of non-necrotizing granulomatous inflammation in one or more tissues and the exclusion of alternative causes of granulomatous disease. Certain clinical features are considered to be highly specific of the disease (e.g., Löfgren's syndrome, lupus pernio, Heerfordt's syndrome) and do not require histological confirmation. New diagnostic guidelines were recently published. Specific clinical criteria have been developed for the diagnosis of cardiac, neurological and ocular sarcoidosis. This article focuses on the clinical presentation and the common differentials that need to be considered when appropriate.

Peripheral nervous system manifestations of rheumatological diseases

Rheumatological diseases result in immune-mediated injury to not only connective tissue, but often components of the peripheral nervous system. These overlap conditions can be broadly categorized as peripheral neuropathies and overlap myositis. The peripheral neuropathies are distinctive as many have unusual presentations such as non-length-dependent, small fiber neuropathies and sensory neuronopathies (both due to dorsal root ganglia dysfunction), multiple mononeuropathies (e.g. vasculitic neuropathies), and even cranial neuropathies. Overlap myositis is increasingly recognized and is often associated with specific autoantibodies. Sarcoidosis also has widespread neurological manifestations and impacts both the peripheral nerves and muscle. Much work is needed to fully characterize the vast presentations of these overlap diseases. Given the rarity of these disorders, they are understudied, resulting in significant knowledge gaps with regards to their underlying pathophysiology and the best treatment approach. A basic knowledge of these disorders is mandatory for both practicing rheumatologists and neurologists as prompt recognition and early initiation of immunotherapy may prevent significant morbidity and permanent disability.

Sarcoidosis-associated acro-osteolysis

Sarcoidosis is characterised by the formation of noncaseating granulomas classically affecting lungs, lymph nodes and skin. Osteoarticular involvement affects up to 15% of patients; however, acro-osteolysis, destruction involving distal phalanges of fingers and toes, associated with sarcoidosis, is extremely rare. A 44-year-old woman with a history of biopsy-proven sarcoidosis managed with prednisone and methotrexate presented with swelling and pain in the distal fingers of her right hand without skin manifestations. Radiographic imaging showed erosion of distal phalanges on second, third and fifth fingers and bone resorption in bilateral toes. A biopsy of the finger lesions showed noncaseating granulomas consistent with sarcoidosis. She was diagnosed with sarcoid acro-osteolysis and started on adalimumab with clinical and radiographic improvement. While most cases of osteoarticular sarcoidosis are asymptomatic and respond to standard immunosuppression, we present a case with progressive and refractory clinical course. This is the first reported case of sarcoid acro-osteolysis affecting the toes.

Distinguishing Blau Syndrome from Systemic Sarcoidosis

PURPOSE OF REVIEW

The purpose of this review is to provide a framework to distinguish Blau syndrome/Early Onset Sarcoidosis and Sarcoidosis clinically. We also discuss relevant differences in genetics, pathogenesis, and management of these diseases.

RECENT FINDINGS

Blau syndrome and Sarcoidosis share the characteristic histologic finding of noncaseating granulomas as well as some similar clinical characteristics; nevertheless, they are distinct entities with important differences between them. Blau syndrome and Early Onset Sarcoidosis are due to one of numerous possible gain-of-function mutations in NOD2, commonly presenting before age 5 with a triad of skin rash, arthritis, and uveitis. However, as more cases are reported, expanded clinical manifestations have been described. In systemic Sarcoidosis, there are numerous susceptibility genes that have been identified, and disease is thought to result from an environmental exposure in a genetically susceptible host. It most often presents with constitutional symptoms and pulmonary involvement and typically affects adolescents and adults. This paper reviews the similarities and differences between Blau syndrome and Sarcoidosis. We also discuss the importance of distinguishing between them, particularly with regard to prognosis and outcomes.

Fluorodeoxyglucose PET/CT of Arthritis in Rheumatic Diseases: A Pictorial Review

Rheumatic diseases are various painful conditions that affect joints, bones, cartilage, tendons, ligaments, and muscles. Arthritis is a typical condition of rheumatic disease. Although rheumatoid arthritis is a representative rheumatic disease, various diseases other than rheumatoid arthritis can also affect joints, and differential diagnosis of rheumatic diseases is often difficult owing to the similar clinical manifestations. However, accurate diagnosis is crucial for an appropriate treatment strategy. The utility of fluorine 18 fluorodeoxyglucose (FDG) PET/CT has been established, and it is widely used for assessing malignancies. In addition to accumulating in tumor cells, FDG also accumulates in inflammatory tissue, allowing FDG PET/CT to demonstrate arthritis. PET/CT allows evaluation of whole-body articular and extra-articular lesions in one examination, representing a key advantage over US and MRI, which allow assessment of only a few regions because of their limited field of view. Although FDG PET/CT is sensitive for detecting inflammatory lesions, the uptake itself is nonspecific; therefore, knowledge of characteristic uptake patterns is necessary to narrow the differential diagnosis in rheumatic disease. Furthermore, pathognomonic extra-articular findings such as vasculitis, skin lesions, lymphadenopathy, and chondritis play an important role in achieving accurate diagnosis. The authors present the FDG PET/CT appearances of (a) rheumatoid arthritis and allied disorders (polymyalgia rheumatica, remitting seronegative symmetrical synovitis with pitting edema, adult-onset Still disease), (b) spondyloarthritis (ankylosing spondylitis, psoriatic arthritis, reactive arthritis, inflammatory bowel disease arthritis, SAPHO [synovitis, acne, pustulosis, hyperostosis, and osteitis] syndrome, chronic recurrent multifocal osteomyelitis), and (c) miscellaneous systemic disorders with arthropathy (relapsing polychondritis, multicentric reticulohistiocytosis, amyloidosis, sarcoidosis, hemophilia). ^©RSNA, 2020.

Sarcoidosis: rarely a single system disorder

Sarcoidosis is a systemic disease with a number of extrapulmonary manifestations, rarely limited to a single system. The objective of this review is to provide a overview of the systemic features of sarcoidosis and their surveillance.

Sarcoidosis is disease that can affect any organ system, resulting in a number of complications that can cause significant morbidity and mortality, including ophthalmological and cardiac complications. A number of investigations play a role in identifying manifestations of sarcoidosis. Respiratory physicians have an important role to play in identifying complications and monitoring patients with sarcoidosis, as they may be the first to encounter them.

Sarcoidosis can involve any organ system, with several complications, particularly ophthalmological and cardiac disease, that are important to recognise in clinical practice and monitor, no matter one's area of expertisehttps://bit.ly/36oLXxm

Acute and Chronic Sarcoid Arthropathies: Characteristics and Treatments From a Retrospective Nationwide French Study

Introduction: We aimed to analyze patients with acute and chronic joint involvements in sarcoidosis.

Methods: This is a retrospective multicenter analysis of patients with proven sarcoidosis, as defined by clinical, radiological, and histological criteria, with at least one clinical and/or ultrasonographic synovitis.

Results: Thirty-nine patients with sarcoid arthropathy were included, and among them 19 had acute sarcoidosis (Lofgren's syndrome). Joint involvement and DAS44-CRP were not significantly different in acute and chronic sarcoid arthropathies. Acute forms were more frequent than chronic sarcoid arthropathy in Caucasians, without any difference of sex or age between these 2 forms. Joint involvement was frequently more symmetrical in acute than chronic forms (100 vs. 70%; p < 0.05), with a more frequent involvement in wrists and ankles in acute forms, whereas the tender and swollen joint counts and the DAS44-CRP were similar between the 2 groups. Skin lesions were significantly more frequent in patients with acute forms [17 (89%) vs. 5 (25%); p < 0.05] and were erythema nodosum in all patients with Löfgren's syndrome and sarcoid skin lesions in those with chronic sarcoidosis. Among 20 patients with chronic sarcoidosis, treatment was used in 17 (85%) cases, and consisted in NSAIDs alone (n = 5; 25%), steroids alone (n = 5; 25%), hydroxychloroquine (n = 2; 20%), methotrexate (n = 3; 15%), and TNF inhibitors (n = 2; 10%). A complete/partial joint response was noted in 14 (70%) cases with a DAS44-CRP reduction of 2.07 [1.85–2.44] (from 3.13 [2.76–3.42] to 1.06 [0.9–1.17]; p < 0.05).

Conclusion: Sarcoid arthropathies have different clinical phenotypes in acute and chronic forms and various treatment regimens such as hydroxychloroquine and methotrexate could be used in chronic forms.

Extrapulmonary Sarcoidosis: A Diagnostic Challenge

Extrapulmonary sarcoidosis accounts for only two percent of the total sarcoid cases. Sarcoidosis affecting the musculoskeletal system alone is even rarer. Diagnosis is based on suggestive history, clinical features, imaging followed by confirmation of non-caseating granulomas on a biopsy. Steroids form the first line of treatment for patients where musculoskeletal system is involved. We report the case of a 26-year-old gentleman who presented with right foot pain and unintentional weight loss. A magnetic resonance imaging (MRI) scan of feet confirmed bilateral stress fractures of both feet. After a battery of investigations and resultant myriad constellation of investigation findings, the diagnosis of sarcoidosis was confirmed on a tissue biopsy obtained via bronchoscopy. This case report discusses the complex journey from presentation to diagnosis and subsequent treatment while also exploring important differentials that need to be ruled out in such scenarios.

Radiographic and Histopathologic Features in Sarcoidosis: A Pictorial Display

Sarcoidosis is a multisystemic granulomatous disorder that can affect virtually any organ. However, pulmonary and thoracic lymph node involvement predominates; abnormalities on chest radiographs are present in 80 to 90% of patients with sarcoidosis. High-resolution computed tomographic (HRCT) scans are superior to chest X-rays in assessing extent of disease, and some CT features may discriminate an active inflammatory component (which may be amenable to therapy) from fibrosis (for which therapy is not indicated). Typical findings on HRCT include micronodules, perilymphatic and bronchocentric distribution, perihilar opacities, and varying degrees of fibrosis. Less common findings on CT include mass-like or alveolar opacities, miliary opacities, mosaic attenuation, honeycomb cysts, and cavitation. With progressive disease, fibrosis, architectural distortion, upper lobe volume loss with hilar retraction, coarse linear bands, cysts, and bullae may be observed. We discuss the salient CT findings in patients with sarcoidosis (with a major focus on pulmonary features) and present classical radiographic and histopathological images of a few extrapulmonary sites.

Bilateral swelling of the forearms revealing muscular sarcoidosis: a case-based review

Muscular sarcoidosis is rarely symptomatic and mainly affects proximal muscles of the lower extremities. However, the distal localization in the upper extremities is rare. We used systematic approach to analyze all relevant literature review and we identified only three cases of muscular sarcoidosis of the upper extremities. We report the case of a 56-year-old woman who presented distal and bilateral swelling of the extensor surface of the forearms revealing muscular sarcoidosis. The laboratory exams associated elevated acute phase reactants with elevated serum angiotensin-converting enzyme levels and normal serum muscle enzymes. Ultrasound and MRI showed a bilateral and symmetrical muscle hypertrophy of the extensors of the fingers. Histological examination of muscle specimen and minor salivary gland biopsy revealed noncaseating epithelioid-cell granulomas. Therefore, the diagnosis of muscular sarcoidosis of the finger extensor muscles was made. Swelling of the forearms disappeared gradually under prednisolone 1 mg/kg/day. We used methotrexate as a steroid-sparing agent. Muscular MRI in sarcoidosis is not specific, but is to make a diagnosis of the lesion to optimize the biopsy which the cornerstone of the diagnosis ofsarcoidosis.

Prevalence, distribution and clinical significance of joints, muscles and bones in sarcoidosis: an 18F-FDG-PET/CT study

OBJECTIVES

In Sarcoidosis joints-muscles-bones (JMBs) localizations are of the least common. ¹⁸F-FDG-PET/CT imaging revolutionized detection of JMBs involvement by adding metabolic activity information and allowing for a comprehensive, whole-body mapping of the disease.

AIM AND METHODS

This study investigated prevalence, distribution, and clinical significance of JMBs sarcoidosis in 195 consecutive patients that underwent ¹⁸F-FDG PET/CT examination.

RESULTS

Joint and bone involvement were encountered in 15% of patients with a mean of the maximum-standardized-uptake-value (SUV_max) of 6.1. Most common location was the axial skeleton. Hypercalciuria was significantly more frequent in patients with osseous involvement (p = 0.003). Muscle activity (SUVmax = 2.4) was encountered in 20% of the patients, most frequently in treatment-naïve (p = 0.02). The muscles of the lower extremities were affected the most. Muscle and bone localization coexist in 50% of the cases. JMBs disease was almost asymptomatic, not related to chronicity but to pulmonary, nodal, and systemic disease. Long-term follow-up and treatment response of affected patients confirmed sarcoidosis.

CONCLUSION

¹⁸F-FDG-PET/CT revealed JMBs localizations and coexistence with other organ sites supporting the concept that sarcoidosis is a systemic disease. By allowing an integrative interpretation of multi-organ involvement in the context of a pattern highly suggestive of sarcoidosis, it strongly keeps-off the diagnosis of malignancy.

Osseous manifestations of sarcoidosis

Sarcoidosis is a systemic multisystem inflammatory disease of unknown etiology. The disease is characterized by formation of non-caseating granulomas. The most common presentation is bilateral hilar lymphadenopathy and lung infiltration, but the disease is very heterogeneous, with an unpredictable clinical course. Musculoskeletal manifestations are common. Bone involvement is less frequent, and usually occurs in patients with chronic multisystem course of the disease. They are most commonly found in the phalanges of hands and feet, and are usually bilateral. The skull, long bones, ribs, pelvis, and axial skeleton may also be affected. Osseous involvement may be asymptomatic but in some cases can cause a severe disability. Imaging techniques are important for diagnosis. Radiological investigations revealed sclerotic or destructive lesions (involving also joints), cystic and punched out lesions and cortical abnormalities. Biopsy is required for differential diagnosis with respect to malignancy. Treatment is a part of systemic therapy and is not needed in all cases. Glucocorticoids and TNF-α antagonists are used for management.

18F-FDG PET/CT in bone sarcoidosis: an observational study

OBJECTIVE

Bone sarcoidosis is usually rare. Imaging procedures such as fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) can reveal bone sarcoidosis with better sensitivity than conventional radiography. We aimed to describe bone sarcoidosis involvement detected with ¹⁸F-FDG PET/CT.

METHODS

This was an observational retrospective study of individuals with pulmonary sarcoidosis who underwent ¹⁸F-FDG PET/CT. According to the ATS/ERS/WASOG criteria, sarcoidosis was diagnosed by the presence of clinical and/or imaging features of sarcoidosis and evidence of non-caseating epithelioid granulomas on a biopsy. We assessed clinical and ¹⁸F-FDG PET/CT characteristics.

RESULTS

Data for 85 patients with sarcoidosis (56.5% female, median age 47 [range 21-80] years) were analyzed. The median follow-up was 4 years. Among 56 patients, sarcoidosis occurred in more than three organs. According to ATS/ERS/WASOG criteria, bone sarcoidosis was diagnosed in 12 (14%) patients. The spine was the most commonly affected location (92%, n = 11), followed by the pelvis (67%, n = 8), sternum (33%, n = 4), humerus (25%, n = 3), and fingers (17%, n = 2). Only peripheral adenopathy was associated with bone sarcoidosis (p = 0.04). Seven patients had a ¹⁸F-FDG PET/CT follow-up, all showing a decrease of bone lesions.

CONCLUSION

Bone sarcoidosis occurred in 14% of patients with sarcoidosis, affecting multiple bones and mostly the axial skeleton. ¹⁸F-FDG PET/CT seems a sensitive tool for diagnosis and follow-up of bone sarcoidosis.

TNF inhibitor treating osseous sarcoidosis and dactylitis: case and literature review

A 49-year-old African American male with multiorgan sarcoidosis presented with recurrent episodes of dactylitis and arthritis. Imaging had shown sarcoid osseous involvement of both hands. This would improve temporarily with high-dose corticosteroids but once tapered, he would experience recurrent flares. Despite several different oral immunosuppressant regimens, significant improvement was only observed after the initiation of adalimumab. Not only was adalimumab successful in symptomatic relief, in addition, patient continues to be in remission with no recurrent episodes of dactylitis. Prednisone was successfully tapered from 40 to 3 mg daily. This improvement with TNF inhibitors has been reported with other manifestations of sarcoidosis including pulmonary and ocular involvements. Osseous sarcoidosis is a very rare presentation, and little information regarding treatment with TNF inhibitors is available. TNF inhibitors should be considered as the next-step therapy in resistant cases of osseous sarcoidosis and dactylitis not responding to corticosteroids and traditional immunosuppressant therapy.

The Burden of Sarcoidosis Symptoms from a Patient Perspective

PURPOSE

The clinical manifestations of sarcoidosis vary widely, depending on the intensity of the inflammation and the organ systems affected. Hence, sarcoidosis patients may suffer from a great variety of symptoms. The aim of this study was to compare the self-reported burden of sarcoidosis patients in Denmark, Germany and the Netherlands, especially the prevalence of fatigue and small fiber neuropathy (SFN)-related symptoms, as well as differences in treatment strategies.

METHODS

A cross-sectional web-based anonymous survey about complaints was conducted among sarcoidosis patients. Patients were invited to take part through the sarcoidosis patient societies as well as through outpatient sarcoidosis clinics in these countries.

RESULTS

The questionnaire was completed by 1072 sarcoidosis patients (152 Danish, 532 German and 388 Dutch). Almost all patients reported having sarcoidosis-associated symptoms (organ-related as well as non-specific, non-organ related). Fatigue was reported by almost all respondents (90%), followed by pulmonary symptoms (72.4%). More than 50% of the respondents were being treated with prednisone, which was comparable in all three countries. In contrast, second- and third-line treatment differed substantially between Denmark, Germany and the Netherlands.

CONCLUSION

Sarcoidosis patients in Denmark, Germany and the Netherlands present with similar self-reported symptoms, organ-related as well as non-specific, non-organ related. Fatigue (90%) and symptoms associated with SFN (86%) were highly prevalent in all three countries.

Myopathies featuring non-caseating granulomas: Sarcoidosis, inclusion body myositis and an unfolding overlap

Granulomatous myopathies are etiologically heterogeneous myopathies, pathologically characterized by the presence of intramuscular granulomas. Treatment outcomes are variable. We aimed to identify prognostic factors of treatment outcomes in myopathies featuring non-caseating granulomas. Sixteen patients were identified (9 sarcoid myopathy, 6 inclusion body myositis, and 1 granulomatous myopathy of indeterminate cause) over a 21-year period. The median age at diagnosis was 67 years in sarcoid myopathy group, and 64 years in inclusion body myositis group. Three inclusion body myositis patients were initially diagnosed with sarcoid myopathy based on the presence of systemic features of sarcoidosis and findings on muscle biopsies, but subsequent biopsies performed because of treatment refractoriness, showed all canonical pathologic features of inclusion body myositis. We identified sarcoplasmic congophilic inclusions in 6 sarcoid myopathy patients without associated rimmed vacuoles or typical weakness pattern of inclusion body myositis. Four inclusion body myositis and 4 of 5 sarcoid myopathy patients with congophilic inclusions were refractory to immunotherapy. Our study portrays the overlapping clinical and pathological features of sarcoid myopathy and inclusion body myositis. The presence of sarcoplasmic congophilic inclusions in sarcoid myopathy may predict an unfavorable outcome of immunosuppressive therapy, but a larger prospective study is required to further validate this observation.