Sarcoidosis involving skeletal muscle: imaging findings and relative value of imaging procedures

Iatrogenic flexor tendon rupture caused by misdiagnosing sarcoidosis-related flexor tendon contracture as tenosynovitis: A case report

BACKGROUND

Sarcoidosis is a multisystem disease characterized by granuloma formation in various organs. Sarcoidosis-related flexor tendon contractures are uncommon in clinical settings. This contracture is similar to stenosing tenosynovitis and potentially leads to misdiagnosis and mistreatment. Herein, we report a rare case of sarcoidosis-related finger flexor tendon contracture that was misdiagnosed as tenosynovitis.

CASE SUMMARY

A 44-year-old woman presented to our department with flexion contracture of the right ring and middle fingers. The patient was misdiagnosed with tenosynovitis and underwent acupotomy release of the A1 pulley of the middle finger in another hospital that resulted in iatrogenic rupture of both the superficial and profundus flexors. Radiological presentation showed multiple sarcoid involvements in the pulmonary locations and ipsilateral forearm. A diagnosis of sarcoidosis was made based on the presence of non-caseating granulomas with tubercles consisting of Langhans giant cells with lymphocyte infiltration on biopsy, and the patient underwent surgical repair for the contracture. After 2 mo, the patient experienced another spontaneous rupture of the repaired middle finger tendon and underwent surgical re-repair. Satisfactory results were achieved at the 10 mo follow-up after reoperation.

CONCLUSION

Sarcoidosis-related finger contractures are rare; thus, caution should be exercised when dealing with such patients to avoid incorrect treatment.

Sarcoidosis, granulomas and myopathy syndromes: A clinical-pathology review

Muscle involvement in sarcoidosis is common by pathologic analysis, but symptomatic disorders are less frequent. Sarcoidosis-related muscle pathology includes non-caseating granulomas, muscle fiber changes that are diffuse or anatomically related to granulomas, and perimysial connective tissue with histiocyte-associated damage. The mechanisms by which granulomas form, enlarge and damage muscle tissues are incompletely understood. Sarcoidosis-related clinical syndromes with muscle involvement include: chronic myopathies with proximal weakness; nodular disorders; subacute onset disorders involving proximal or eye muscles; myalgia or fatigue syndromes; and, possibly, inclusion body myositis-like disorders. Corticosteroid treatment may benefit some syndromes, but clinical trials are necessary.

Clinical characteristics and outcome in muscular sarcoidosis: a retrospective cohort study and literature review

We evaluated the clinical features and treatment response of patients with muscular sarcoidosis. A retrospective cohort of 12 patients showed muscle weakness in 11 and myalgia in seven. One had focal myositis. Four had a negative medical history for sarcoidosis. Muscle imaging showed muscle edema in all and replacement of muscle tissue by fat in half of patients. Muscle biopsy showed non-caseating granulomas in six of nine patients and inflammation without granulomas in three. None of the muscle biopsies showed features of inclusion body myositis. Imaging in three patients without muscle biopsy showed focal intramuscular masses or a 'tiger man' appearance typical for muscular sarcoidosis. Treatment consisted of glucocorticoids in 11, additional methotrexate or azathioprine in seven and infliximab in two patients. Half of the patients had symptoms leading to substantial disability (modified Rankin scale score >1) at last follow-up. A literature review of articles describing more than one muscular sarcoidosis patient published in the last 25 years identified 153 additional patients. We found muscular sarcoidosis to be a rare and often disabling disease which may be recognized by typical muscle imaging characteristics and add focal myositis to the muscular phenotypes of sarcoidosis.

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.

Granulomatous Myositis Associated With Acetylcholine Receptor Antibodies Without Clinical Myasthenia

ABSTRACT

Myasthenia gravis associated with concurrent inflammatory myopathy is a rare but well-described syndrome, most often seen in patients with thymoma. We present a case of biopsy-proven granulomatous myositis associated with positive acetylcholine receptor binding, blocking, and modulating and antistriated antibodies, without clear clinical symptoms of myasthenia gravis and in the absence of thymoma. In addition, we include rarely reported neuromuscular ultrasound findings of granulomatous myositis in a patient without sarcoidosis. Inflammatory myopathy may precede development of myasthenia gravis in myasthenia gravis associated with concurrent inflammatory myopathy, and it is important to remain vigilant for symptoms suggestive of myasthenia gravis, especially in the presence of positive myasthenia-associated antibodies.

MRI and muscle imaging for idiopathic inflammatory myopathies

Although idiopathic inflammatory myopathies (IIM) are a heterogeneous group of diseases nearly all patients display muscle inflammation. Originally, muscle biopsy was considered as the gold standard for IIM diagnosis. The development of muscle imaging led to revisiting not only the IIM diagnosis strategy but also the patients' follow-up. Different techniques have been tested or are in development for IIM including positron emission tomography, ultrasound imaging, ultrasound shear wave elastography, though magnetic resonance imaging (MRI) remains the most widely used technique in routine. Whereas guidelines on muscle imaging in myositis are lacking here we reviewed the relevance of muscle imaging for both diagnosis and myositis patients' follow-up. We propose recommendations about when and how to perform MRI on myositis patients, and we describe new techniques that are under development.

Symptomatic nodular myopathy: an atypical presentation of sarcoidosis

Symptomatic myopathy is a very rare extrapulmonary manifestation of sarcoidosis that may not be readily recognised in the absence of a known history of sarcoid. Nodular myopathy is the most uncommon subtype of musclar sarcoidosis and, when encountered, establishing the diagnosis can be challenging. We present a case of symptomatic nodular myopathy as a first presentation of sarcoidosis in a young man who required a multidisciplinary approach to diagnose. The patient presented to our radiology department following a short period of flu-like illness and multiple soft tissue lesions. Biopsy of the lesions demonstrated noncaseating granulomata, and a diagnosis of sarcoidosis was established after important differential diagnoses were excluded. We present a literature review of sarcoid-related myopathy and the multimodality imaging characteristics of the different subtypes.

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.

Tiger Man Sign-F-18 FDG PET CT Scan Pattern in Muscular and Cutaneous Sarcoidosis: A Case Report and Literature Survey

Sarcoidosis is a chronic granulomatous disorder of unknown etiology which primarily affects the respiratory system. However, 0.5%–2.5% of patients with sarcoidosis show muscle involvement, namely sarcoid myopathy. F-18 Fluorodeoxyglucose positron-emission tomography (F-18 FDG PET) has become an important component of the diagnostic algorithm of these patients, owing to its ability to assess disease extent and identify occult sites of disease involvement and guiding sites of biopsy. Awareness of pattern of FDG uptake in sarcoid myopathy not only helps in identifying muscular involvement in already known cases but also helps in the initial diagnosis of sarcoidosis as in the present case.

Myopathies with finger flexor weakness: Not only inclusion-body myositis

Muscle disorders are characterized by differential involvement of various muscle groups. Among these, weakness predominantly affecting finger flexors is an uncommon pattern, most frequently found in sporadic inclusion-body myositis. This finding is particularly significant when the full range of histopathological findings of inclusion-body myositis is not found on muscle biopsy. Prominent finger flexor weakness, however, is also observed in other myopathies. It occurs commonly in myotonic dystrophy types 1 and 2. In addition, individual reports and small case series have documented finger flexor weakness in sarcoid and amyloid myopathy, and in inherited myopathies caused by ACTA1, CRYAB, DMD, DYSF, FLNC, GAA, GNE, HNRNPDL, LAMA2, MYH7, and VCP mutations. Therefore, the finding of finger flexor weakness requires consideration of clinical, myopathological, genetic, electrodiagnostic, and sometimes muscle imaging findings to establish a diagnosis.

A review of the musculoskeletal manifestations of sarcoidosis

Sarcoidosis is a systemic disease of unknown aetiology that is characterized by granulomatous inflammation that can develop in almost any organ system. Musculoskeletal manifestations are seen in up to one-third of patients, ranging from arthralgia through to widespread destructive bone lesions. Inflammatory tendon lesions and periarticular swelling are more common than true joint synovitis. Despite advances in our understanding of the pathophysiology of the disease, diagnosis remains challenging. Definitive diagnosis, irrespective of organ site involvement, hinges on histological confirmation of non-caseating granuloma combined with an appropriate clinical syndrome. Musculoskeletal involvement usually develops early in the disease course. Imaging modalities, particularly fluorodeoxyglucose PET, are helpful in delineating the extent of involvement and measuring disease activity. Bone involvement may only become apparent following isotope imaging. Corticosteroids remain the cornerstone of treatment. MTX is the steroid-sparing agent of choice unless there is renal involvement. Biologic therapies are sometimes used in severe disease, although the evidence base for efficacy is inconsistent.

[Musculoskeletal manifestations of sarcoidosis]

Musculoskeletal manifestations in the context of sarcoidosis are frequently observed. The rheumatologist regularly encounters this disease in clinical practice. In the present review, we aim to give a current overview of the manifestations and treatments relevant to the practicing rheumatologist. The most frequently encountered manifestation is Lofgren's syndrome, which is characterized by bilateral ankle periarthritis, bilateral hilar lymphadenopathy, and erythema nodosum and has an excellent prognosis. Chronic arthropathy most commonly manifests as oligoarthritis, which sometimes hampers its differentiation from spondylarthropathies, especially when sacroiliitis, enthesitis or dactylitis are simultaneously present. Isolated vertebral granulomas are rare and require infectious and malignant disorders to be excluded, since there are no specific imaging findings that are exclusively found in vertebral sarcoidosis. The presence of granulomas in skeletal muscle is common in muscle biopsies, whereas clinically overt myopathy is present in only around 1-2% of patients. Therapeutic responses vary among the different clinical phenotypes. Non-steroidal anti-inflammatory drugs and low to medium dose glucocorticoids are the first-line therapy for musculoskeletal manifestations and often lead to adequate disease control in acute sarcoidosis. When these are ineffective or not tolerated, steroid-sparing agents are increasingly used in chronic sarcoidosis. Evidence for all medications used in sarcoid-related arthritis is comparatively scant. When supplementing vitamin D, the possible development of hypercalcemia, even at standard doses, needs to be considered; the optimal therapeutic levels for the prevention of medication-induced osteoporosis in sarcoidosis have not been firmly established.

Muscular sarcoidosis involving the chest and abdominal walls: case report with MR imaging

Sarcoidosis is an inflammatory disorder that is characterized by the presence of noncaseating granulomas in tissues, involving many organs and tissues. Extra-pulmonary, especially muscular sarcoidosis is a rare condition. The most common location of the muscular sarcoidosis is known to be the proximal muscles of the extremities; however, there have been no cases of diffuse involvement of the chest and abdominal wall muscles. Here, we report a rare muscular sarcoidosis with infiltrative pattern in the chest and abdominal wall muscles and describe the MR imaging findings that were mistaken as lymphoma at initial diagnosis. Although our case did not show characteristic MR findings of muscular sarcoidosis, clinicians or radiologists who are aware of these imaging features can perform early systemic survey for sarcoidosis. Also muscle biopsy is very important to confirm the sarcoidosis and distinguish it from other tumors.

MR Imaging of Atraumatic Muscle Disorders

Atraumatic disorders of skeletal muscles include congenital variants; inherited myopathies; acquired inflammatory, infectious, or ischemic disorders; neoplastic diseases; and conditions leading to muscle atrophy. These have overlapping appearances at magnetic resonance (MR) imaging and are challenging for the radiologist to differentiate. The authors organize muscle disorders into four MR imaging patterns: (a) abnormal anatomy with normal signal intensity, (b) edema/inflammation, (c) mass, and (d) atrophy, highlighting each of their key clinical and imaging findings. Anatomic muscle variants, while common, do not produce signal intensity alterations and therefore are easily overlooked. Muscle edema is the most common pattern but is nonspecific, with a broad differential diagnosis. Autoimmune, paraneoplastic, and drug-induced myositis tend to be symmetric, whereas infection, radiation-induced injury, and myonecrosis are focal asymmetric processes. Architectural distortion in the setting of muscle edema suggests one of these latter processes. Intramuscular masses include primary neoplasms, metastases, and several benign masslike lesions that simulate malignancy. Some lesions, such as lipomas, low-flow vascular malformations, fibromatoses, and subacute hematomas, are distinctive, but many intramuscular masses ultimately require a biopsy for definitive diagnosis. Atrophy is the irreversible end result of any muscle disease of sufficient severity and is the dominant finding in disorders such as the muscular dystrophies, denervation myopathy, and sarcopenia. This imaging-based classification, in correlation with clinical and laboratory data, will aid the radiologist in interpreting MR imaging findings in patients with atraumatic muscle disorders. ^©RSNA, 2018.

Extensive intramuscular manifestation of sarcoidosis with initially missed diagnosis and delayed therapy: a case report

Background

Sarcoidosis is a multisystemic granulomatous disorder, which in nearly all cases involves the lungs and other organs. Isolated forms of sarcoidosis within the muscles, but without lung involvement, are extremely rare and can lead to delayed or even false diagnosis.

Case presentation

A 52-year-old white, Swiss man presented with painful arm cramps and a history of symptoms over the previous 3 years. In the initial clinical investigation, our patient also showed edema in both legs without any other complaints. After performing an magnetic resonance imaging scan of his extremities and a positron emission tomography/computed tomography scan, diffuse myositis was described. The subsequent muscle biopsy provided the surprising diagnosis of muscle sarcoidosis, without involvement of the lungs or any other organ. After starting therapy with glucocorticoids, his symptoms improved immediately.

Conclusions

Sarcoidosis is a common disorder, which in most cases affects the lungs. In this case report an isolated sarcoidosis is described without lung involvement, but with involvement of the muscles of the extremities and the trunk. Reported cases of sarcoidosis only involving skeletal muscle and without lung involvement are extremely rare. Radiologists should consider this presentation of sarcoidosis to avoid delayed diagnosis and therapy.

Skeletal Muscle Involvement in B-Cell Lymphoma: Two Cases Illustrating the Contribution of Imaging to a Clinically Unsuspected Diagnosis

Skeletal muscle lymphoma is rare, comprising only a very small subset of lymphoma cases. There are characteristic imaging features which, if recognized, can prevent delay in diagnosis and treatment, particularly when not suspected clinically. Herein, we report two cases of skeletal muscle lymphoma with nearly identical imaging features; the first is an example of primary muscle lymphoma in a 17-year-old boy with back and thigh pain, and the second represents lymphoma recurrence in a 55-year-old man with HIV. Characteristic features seen on MRI were key in raising suspicion for the disease and helped prevent a delay in pathologic diagnosis.

Apparent diffusion coefficient map of a case of extramedullary plasmacytoma

Plasmacytomas are rare tumors, which arise from the monoclonal proliferation of malignant plasma cells. They may affect either the bony skeleton or rarely the soft tissues, the latter being referred to as extramedullary or extraosseous. We report a case of an extramedullary plasmacytoma that presented as a soft tissue mass involving the muscles of the left leg, in a patient who was previously treated for multiple myeloma. We describe the MR Imaging characteristics of the tumor and highlight the usefulness of diffusion-weighted imaging with apparent diffusion coefficient mapping.

Life-Threatening Hypercalcemia Revealing Diffuse and Isolated Acute Sarcoid-Like Myositis: A New Entity? (A Case-Series)

Up to 50% patients with sarcoidosis display extra-pulmonary disease. However, initial and isolated (ie, without lung disease) acute muscular involvement associated with pseudo-malignant hypercalcemia is very uncommon. We report on 3 cases of life-threatening hypercalcemia revealing florid and isolated acute sarcoid-like myositis.All patients complained of fatigue, progressive general muscle weakness, and weight loss. Laboratory tests showed a severe life-threatening hypercalcemia (>3.4 mmol/L). Hypercalcemia was associated with increased serum level of 1,25-(OH)2 vitamin D and complicated with acute renal failure. One patient displayed acute pancreatitis due to hypercalcemia.In all cases, PET-scan, performed for malignancy screening, incidentally revealed an intense, diffuse, and isolated muscular fluorodeoxyglucose (FDG) uptake consistent with diffuse non-necrotizing giant cells granulomatous myositis demonstrated by muscle biopsy. Of note, creatine phosphokinase blood level was normal in all cases. No patients displayed the usual thoracic features of sarcoidosis.All patients were treated with high dose steroids and achieved rapid, complete, and sustained remission. A review of English and French publications in Medline revealed 5 similar published cases.Steroid-sensitive acute sarcoid-like myositis causing high calcitriol levels and life-threatening hypercalcemia should be recognized as a separate entity.

Intramuscular granular cell tumor: emphasizing the stripe sign

We present a case of an intramuscular granular cell tumor in the thigh manifesting a 'stripe sign' on magnetic resonance imaging (MRI). This MR finding may correspond with the entrapped muscle fibers within the tumor, which demonstrated parallel arrangement on histopathologic examination. In addition, other disease entities characterized by the presence of this sign such as proliferative myositis, heterotopic ossification, and muscular sarcoidosis will be reviewed.

[67Ga scintigraphy as a therapeutic marker for spinal cord and muscular sarcoidosis: A case report]

A 70-year-old woman was admitted to our hospital because of the right limb pain and gait disturbance. (67)Ga scintigraphy showed an increased uptake in the spinal cord, mediastinal lymph node and right tibialis anterior muscle. Based on the histopathological findings of epithelioid cell granuloma in endobronchial ultrasound-guided transbronchial needle aspiration of lymph node, she was diagnosed as having probable spinal cord/muscular sarcoidosis. After she was treated with oral prednisolone, her limb pain and gait disturbance improved. Furthermore, uptake in (67)Ga scintigraphy was reduced after the treatment. In conclusion, (67)Ga scintigraphy is useful not only for diagnosis, but also for estimating the efficiency of the treatment for sarcoidosis involving multiple organs such as the spinal cord and skeletal muscle.

Sixth nerve palsy associated with obstruction in Dorello's canal, accompanied by nodular type muscular sarcoidosis

A 52-year-old Japanese woman complaining of horizontal double vision for 10 days was admitted to our hospital. Neurological examination revealed left abducent nerve palsy and muscle swelling in her thighs. Brain MRI showed obstruction in the spinal fluid space of the left Dorello's canal, which transmits a portion of the abducent nerve. In Ga-67-enhanced citrate scintigraphy, wide accumulation was seen in her bilateral thighs, lower legs, and gluteus muscles. Muscular MRI showed a star-shaped central structure on short tau inversion recovery (STIR) images, and the three stripes sign on T2-weighted images. These MRI findings indicated nodular-type muscular sarcoidosis. A muscle biopsy from the quadriceps femoris showed granulomatous epithelioid giant cells and non-necrotizing chronic lymphadenitis, which also indicate sarcoidosis. Her condition was considered to be caused by sarcoid granulomas obstructing Dorello's canal. She was treated with oral prednisolone (1 mg·kg(-1)·day(-1)) and her symptoms and MRI findings improved. This is the first known report of abducent nerve impairment in Dorello's canal, other than fetal hypoplasia. Brain MRI, muscular MRI, and muscle biopsy are useful for the diagnosis of abducent nerve palsy, and it is important to consider Dorello's canal obstruction by sarcoidosis. Complete remission can be achieved with proper treatment.

Extrapulmonary manifestations of sarcoidosis

Sarcoidosis is a systemic disease characterized by the development of epithelioid granulomas in various organs. Although the lungs are involved in most patients with sarcoidosis, virtually any organ can be affected. Recognition of extrapulmonary sarcoidosis requires awareness of the organs most commonly affected, such as the skin and the eyes, and vigilance for the most dangerous manifestations, such as cardiac and neurologic involvement. In this article, the common extrapulmonary manifestations of sarcoidosis are reviewed and organ-specific therapeutic considerations are discussed.

FINGER FLEXION CONTRACTURE DUE TO MUSCULAR INVOLVEMENT OF SARCOIDOSIS

We describe a rare experience with the treatment of a patient with finger flexion contracture caused by muscular involvement of sarcoidosis, who had been misdiagnosed as having a trigger finger and underwent surgical release of the A1 pulley of her little finger. This report serves as a reminder that muscular involvement of sarcoidosis can cause finger flexion contractures.

Hepatosplenic and muscular sarcoidosis: characterization with MR imaging

Sarcoidosis is a multisystem disorder of unknown etiology that involves multiple organs. Computed tomography is the first-line imaging modality for diagnosing sarcoidosis because of its capacity to detect hilar lymphadenopathy and pulmonary lesions. Magnetic resonance (MR) imaging provides good soft tissue contrast that is useful for detecting sarcoidosis in some body parts, including skeletal muscle. Signal intensity on pre- and postcontrast T(1)- and T(2)-weighted imaging may reflect disease activity and the pathological appearance of sarcoidosis. In this review, we demonstrate these conventional MR imaging findings of hepatosplenic and muscular sarcoidosis and describe the usefulness of diffusion-weighted imaging for detecting sarcoidosis.

Primary musculoskeletal sarcoidosis

Sarcoidosis is a well-described clinical entity with several types of presentation among different organ systems. However, primary musculoskeletal manifestation is a rare and seldom-described manifestation. A retrospective review of patients seen at our institution from 1999 to 2009 was performed to identify patients with such presentation. Eleven patients with musculoskeletal sarcoidosis were identified. Seven patients presented with solitary lesions, while 4 presented with multiple foci of disease. Histologically, all lesions revealed granulomatous inflammation consistent with sarcoidosis. Cultures and gram stain were negative in all patients. One patient was found to have evidence of pulmonary sarcoidosis after diagnosis of musculoskeletal sarcoidosis. Eight patients had primarily soft tissue involvement with visible masses, while 3 patients had primarily osseous involvement with no mass. Pain was reported by 9 of 11 patients. On magnetic resonance imaging, all lesions were dark on T1, bright on T2, and poorly marginated. Magnetic resonance imaging was noted to be more accurate in revealing the pathology than radiographic imaging. Four patients underwent complete excision and 1 received a steroid injection. The remaining patients required no further treatment after diagnosis. Musculoskeletal sarcoidosis is rare and can present as single or multiple lesions. Definitive diagnosis is made by biopsy. The decision to operate should be based on symptoms, issues with cosmesis, impending fractures, growth, and/or involvement of neuro-vascular structures. Patients should be evaluated for pulmonary involvement.

An unusual presentation of muscular sarcoidosis

Sarcoidosis is a noncaseating granulomatous disease that involves multiple organs, most commonly the lungs, lymph nodes, skin, and eyes, but may be clinically evident in any organ system. Symptomatic muscular sarcoidosis is very rare and has been reported in only 1.4% of known sarcoidosis cases, while skeletal involvement has been reported in 1-13%. Different types of muscular and osseous sarcoidosis have been described in the literature. We present a case of muscular sarcoidosis, which is unique in its clinical presentation and imaging findings. The presence of the marked periosteal reaction, which has never been described with muscular sarcoidosis, also makes this case unique.

Radiological manifestations of sarcoidosis

Sarcoidosis is an immune system disorder characterised by non-necrotising granulomas. Pulmonary involvement is the most common presentation of sarcoidosis, but it can manifest in any organ. Other commonly involved organ systems include the lymph nodes (especially the intrathoracic nodes); the skin; the eyes; the liver; the heart; and the nervous, musculoskeletal, renal, and endocrine systems. The typical and atypical imaging features of multisystemic involvement of sarcoidosis have been discussed with review of the gamut of radiological manifestations of thoracic, cardiac, CNS, abdominal and musculoskeletal sarcoidosis.

Apport de la tomographie par émission de positons pour le diagnostic de sarcoïdose au cours d'une myopathie granulomateuse

INTRODUCTION

Granulomatous myositis is a rare condition that has been described in association with sarcoidosis. In the absence of sarcoidosis or other underlying disease, a diagnosis of isolated granulomatous myositis is considered.

OBSERVATION

A 61-year-old African man presented with progressive limitation in running and proximal atrophy of the lower limbs for the past year. Quadricipital muscle biopsy revealed non-caseating epithelioid granulomas and multinuclear giant cells. Whole body fluorodeoxyglucose positron emission tomography ((18)FDG-PET) revealed hypermetabolic activity of salivary and lachrymal glands, and mild hypermetabolism in the mediastinal lymph nodes. Minor salivary gland biopsy was consistent with sarcoidosis.

CONCLUSION

To our knowledge, this is the first reported case of sarcoid myopathy demonstrating the diagnostic usefulness of (18)FDG-PET.

Imaging of muscle disorders in children

Muscle inflammation is a relatively common pathological process in childhood. The diagnosis of the underlying cause relies on an appreciation of the pattern of clinical features, as well as the results of biochemical, histological and radiological investigations. Often the clinical and biochemical features are non-specific and insensitive. Consequently, the radiological abnormalities are very important in establishing a diagnosis and an understanding of the imaging features of muscle inflammatory disorders in childhood is needed. Some of the imaging protocols needed to investigate a variety of muscle and soft-tissue inflammatory conditions in childhood are reviewed in this article. Those features that are helpful in narrowing the differential diagnosis are indicated and a logical approach to the investigation of affected children is provided. The value of MR imaging is highlighted.

MR Imaging: Arthropathies and Infectious Conditions of the Elbow, Wrist, and Hand

The superior soft tissue contrast and multiplanar capability of MR imaging has contributed to earlier diagnosis and implementation of effective treatment for a variety of arthropathies and infectious conditions of the elbow, wrist, and hand. Because of overlapping clinical signs and symptoms, MR imaging plays an important role in delineating the features and staging of each of these conditions. This article discusses the seropositive and seronegative inflammatory arthropathies, with emphasis on early detection and surveillance, as well as gout, synovial osteochondromatosis, pigmented villonodular synovitis, tenosynovitis, and de Quervain's tenosynovitis. Certain noninflammatory arthritides and infectious conditions are also reviewed.

Sarcoidosis presenting as prepatellar bursitis

A 61-year-old woman complained of a subcutaneous mass in her right knee. MR images revealed a well-defined subcutaneous mass in the prepatellar region, containing some fluid and foci of short T2. The lesion showed some marginal contrast uptake after an administration of meglumine gadopentetate (Gd-DTPA), consistent with prepatellar bursitis. The pathological specimen, however, revealed subcutaneous sarcoidosis involving the bursa.

Pseudotumeur musculaire avec hypercalcémie et insuffisance rénale aiguë révélant une sarcoïdose

At the end of assessment of an hypercalcemia with acute renal failure in a seventy year-old man, is discovered a tumorlike muscular sarcoidosis of both thighs whose steroid treatment quickly proves effective. Rarity of such forms urges us to report this observation which allows to remind that, in case of a suggestive picture of sarcoidosis, it is necessary to look minutely for any muscular abnormality.

MRI of Sarcoidosis Patients with Musculoskeletal Symptoms

OBJECTIVE

Our objective was to determine MRI findings in sarcoidosis patients with musculoskeletal symptoms.

CONCLUSION

In sarcoidosis patients with musculoskeletal complaints, MRI reveals marrow and soft-tissue lesions that are occult or underestimated on radiographs. Axial and large-bone lesions may resemble osseous metastases on MRI. Most lesions detected are nonspecific in appearance, except nodular muscle lesions. MRI reveals features suggesting the diagnosis, but with standard protocols, no pathognomonic MRI features were determined.

Imaging Findings in Three Cases of the Nodular Type of Muscular Sarcoidosis

OBJECTIVE

Sarcoidosis is a granulomatous multisystem disorder that may uncommonly involve muscle. We report the sonographic and MRI findings in three cases of the nodular type of muscular sarcoidosis.

CONCLUSION

Intramuscular hypoechoic well-defined nodules in young patients or patients with a history of sarcoidosis suggest the diagnosis of intramuscular sarcoid. MRI is useful in detecting muscle sarcoid, evaluating the extent and distribution of muscle involvement, and monitoring the patient during follow-up after steroid therapy. MRI showed nodules that were iso- or hyperintense relative to muscle on T1-weighted sequences. On T2-weighted images and STIR sequences, we observed numerous intramuscular nodules of homogeneous high signal intensity. All nodules enhanced homogeneously on contrast-enhanced T1-weighted sequences. Disappearance of all nodules was seen on follow-up sonograms and MR images after patients had received steroid therapy.