Sarcoidosis of the eye, orbit, and central nervous system. Role of MR imaging

Overcoming the Elusiveness of Neurosarcoidosis: Learning from Five Complex Cases

The involvement of the central nervous system in sarcoidosis can manifest with a variety of neurological symptoms, and most of them can be nonspecific. The diagnosis of neurosarcoidosis (NS) can therefore be very challenging without a tissue biopsy. Both computed tomography (CT) and magnetic resonance imaging (MRI) are important imaging modalities in the diagnosis of NS, and MRI is the modality of choice due to its superior soft-tissue contrast resolution. We present a case series of NS with interesting neuroimaging features, complex neurological presentations, and clinical courses. We identify five cases presenting with clinically isolated neurosarcoidosis (CINS) without any other signs or symptoms of systemic disease which were diagnosed as NS on biopsy. In the first case, we describe a patient with an intramedullary cervical spinal cord lesion. In the second case we describe a patient presenting with inflammatory changes and enhancement in the orbit. The third case demonstrates a lesion with calcification around the region of the foramen of Monro. The fourth case shows multiple ring-enhancing lesions. Lastly, the fifth case exhibits unusual findings with both optic neuritis and a cerebellar nodule. We aim to describe the complicated clinical course with neurological workup, neuro-imaging, and eventual diagnosis and treatment of these challenging cases to highlight the variable presentations of NS. This case series will remind clinicians that NS should always be in the differential diagnosis when a patient presents with nonspecific neurological symptoms with unusual neuroimaging findings.

Relapsing Demyelinating Syndromes in Children: A Practical Review of Neuroradiological Mimics

Relapsing demyelinating syndromes (RDS) in children encompass a diverse spectrum of entities including multiple sclerosis (MS) acute disseminated encephalomyelitis (ADEM), aquaporin-4 antibody associated neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOG-AD). In addition to these, there are “antibody-negative” demyelinating syndromes which are yet to be fully characterized and defined. The paucity of specific biomarkers and overlap in clinical presentations makes the distinction between these disease entities difficult at initial presentation and, as such, there is a heavy reliance on magnetic resonance imaging (MRI) findings to satisfy the criteria for treatment initiation and optimization. Misdiagnosis is not uncommon and is usually related to the inaccurate application of criteria or failure to identify potential clinical and radiological mimics. It is also notable that there are instances where AQP4 and MOG antibody testing may be falsely negative during initial clinical episodes, further complicating the issue. This article illustrates the typical clinico-radiological phenotypes associated with the known pediatric RDS at presentation and describes the neuroimaging mimics of these using a pattern-based approach in the brain, optic nerves, and spinal cord. Practical guidance on key distinguishing features in the form of clinical and radiological red flags are incorporated. A subsection on clinical mimics with characteristic imaging patterns that assist in establishing alternative diagnoses is also included.

Clinical and radiographic features of hydrolyzed MIRAgel scleral buckles: A comparative analysis

The MIRAgel (hydrogel) scleral buckle, introduced in the 1980s, was a novel material to repair retinal detachments. It was later discontinued due to the frequency of long-term complications related to buckle hydrolysis and expansion. These complications included pain, limited extraocular motility, and more serious complications such as infection or scleral perforation, which ultimately necessitated surgical extraction as late as 20-30 years after placement. Prompt and proper diagnosis and treatment is often delayed as these buckle-associated complications frequently mimic other orbital pathologies such as tumors or infections. The hydrolyzed MIRAgel buckle exhibits distinct radiographic features that are helpful in arriving at the correct diagnosis, particularly in cases of ambiguous clinical presentation or history. Here, we expand on the previously described radiographic features of hydrolyzed MIRAgel and compare them to features of common, mimicking orbital pathology.

[Neurosarcoidosis of the anterior visual pathway (a case report and literature review)]

Sarcoidosis is a multisystem granulomatous disorder of unknown nature. Patients often present with pulmonary, skin, eye, and orbital lesions. Involvement of the central nervous system (CNS) is accompanied by granulomatous leptomeningitis and damage to the basal brain structures with formation of granulomas near the cranial nerves, hypothalamus, pituitary gland, cavernous sinuses, optic chiasm, and intracranial optic nerves. The optic nerves can be affected independently of the other CNS regions, which may be the first manifestation of the disease. The article presents two clinical cases of sarcoidosis affecting the anterior visual pathway. Diagnosis of the disease was associated with certain difficulties. A biopsy revealed a sarcoidosis lesion.

Neurosarcoidosis As a Rare Differential Diagnosis for Single Or Multiple Lesions of the Nervous System

Objective: Sarcoidosis is a multisystemic granulomatous disease of unknown cause which affects the lung or bilateral hilar lymphadenopathy in over 90% of the cases. Neurosarcoidosis (NS) is rare and accounts for approximately 5 - 15% of the cases. Involvement of all parts of the central and peripheral nervous system is possible with various clinical symptoms, e. g. seizures, hydrocephalus, optic/facial nerve palsy or hearing loss.Methods: We screened the neuropathological data bases and the medical records of two neurosurgical university hospitals for cases of NS. All these cases had been verified by surgical biopsy. We retrospectively evaluated the patient's records with special regard to the histopathology reports and specific clinical symptoms.Results: We identified 9 cases of NS between 1994 and 2014 (3 female, 6 male patients). The average age at the time of diagnosis of NS was 41,4 years. Various clinical symptoms like hydrocephalus (n = 3), seizures (n = 1), meningitis (n = 1), optical nerve involvment with vision disorder (n = 1), myelitis with paraplegia (n = 1), mastoiditis with hearing loss (n = 1), back pain syndrome (n = 2) were present. 7 patients were treated with corticosteroids, 1 patient with cyclophosphamide and 1 with a combination of corticosteroids and methotrexate.Conclusion: NS is a rare but potentially life-threatening disease. It is difficult to distinguish sarcoidosis from other granulomatous diseases, infectious diseases like tuberculosis, multiple sclerosis or neoplasm. For a definite diagnosis, a neurosurgical biopsy with histological evidence of noncaseating epithelioid cell granulomas is required, followed by multidisciplinary treatment.

Case report: middle-aged woman from Ghana with unsteady gait and enlarging cerebellar mass

RATIONALE

Neurosarcoidosis (NS) is an uncommon manifestation of systemic sarcoidosis, with a propensity for middle-agedwomen. Often discovered only at autopsy, rates of neurologic involvement (5%-10%) reported in the literature underscore a lack of sensitivity and specificity in current diagnostic methods.

PATIENT CONCERNS

Herein, we describe a 53-year-old woman who presented with gait imbalance and distal extremity muscular weakness. She was known to harbor a brain mass (4 years in duration) that was monitored and recently seemed to enlarge.

DIAGNOSIS

A subsequent brain biopsy showed necrotizing granulomatous inflammation suggestive of NS. However, no clinical or radiologic evidence of activity was found in other organs.

INTERVENTIONS AND OUTCOMES

Ultimately, endo and transbronchial biopsies were performed, providing histologic confirmation of systemic sarcoidosis.

LESSONS

This approach is advised in all instances of suspected NS where systemic involvement is in question.

Ophthalmic manifestations of systemic diseases--part 2: metabolic, infections, granulomatoses, demyelination, and skeletal dysplasias

The orbit and globe can be secondarily involved in various systemic diseases. These range from tumor and tumorlike conditions, metabolic, infective, inflammatory, granulomatous demyelinating diseases, and skeletal dysplasias. In this article, we discuss the imaging appearances of the remaining systemic pathologies affecting the orbit such as (1) endocrine or metabolic, (2) infectious, (3) inflammatory or granulomatous, (4) demyelinating diseases, and (5) skeletal dysplasias. As the imaging appearances of various systemic diseases tend to overlap, we also introduce a list of pattern-based systemic differential diagnoses for commonly encountered orbital imaging findings. Awareness of the imaging appearances of the various ophthalmic manifestations of systemic diseases can help a radiologist to suggest the most appropriate differential diagnosis to guide further workup and facilitate correct treatment.

Diffusion-weighted imaging of orbital masses: multi-institutional data support a 2-ADC threshold model to categorize lesions as benign, malignant, or indeterminate

BACKGROUND AND PURPOSE

DWI has been increasingly used to characterize orbital masses and provides quantitative information in the form of the ADC, but studies of DWI of orbital masses have shown a range of reported sensitivities, specificities, and optimal threshold ADC values for distinguishing benign from malignant lesions. Our goal was to determine the optimal use of DWI for imaging orbital masses through aggregation of data from multiple centers.

MATERIALS AND METHODS

Source data from 3 previous studies of orbital mass DWI were aggregated, and additional published data points were gathered. Receiver operating characteristic analysis was performed to determine the sensitivity, specificity, and optimal ADC thresholds for distinguishing benign from malignant masses.

RESULTS

There was no single ADC threshold that characterized orbital masses as benign or malignant with high sensitivity and specificity. An ADC of less than 0.93 × 10(-3) mm(2)/s was more than 90% specific for malignancy, and an ADC of less than 1.35 × 10(-3) mm(2)/s was more than 90% sensitive for malignancy. With these 2 thresholds, 33% of this cohort could be characterized as "likely malignant," 29% as "likely benign," and 38% as "indeterminate."

CONCLUSIONS

No single ADC threshold is highly sensitive and specific for characterizing orbital masses as benign or malignant. If we used 2 thresholds to divide these lesions into 3 categories, however, a majority of orbital masses can be characterized with >90% confidence.

Orbital lymphoma: imaging features and differential diagnosis

Purpose

Patterns of orbital lymphoma at diagnosis and follow-up are described. We also discuss differential diagnosis of orbital masses.

Materials and methods

This pictorial review contains 19 cases of orbital lymphoma before and after treatment. Superior-lateral quadrant and extra-conal location were observed predominantly. Effective response after treatment was presented on follow-up imaging, although few local relapses were found. Further follow-up showed no changes of residual images.

Discussion

Location of orbital masses can help in the differential diagnosis. Moreover, imaging features of lymphoma at diagnosis can be useful in planning surgical biopsy. Pattern of follow-up described may be relevant on monitoring imaging.

Teaching points

• Orbital lymphoma involves mainly superior-lateral quadrant and the orbital structures inside.

• Location of retrobulbar mass-like lesions are useful information in the differential diagnosis.

• Satisfactory response is detected after treatment, however relapse is noted, so follow-up is needed.

Lacrimal glands: size does matter!

A 40-year-old woman presented with vague headaches and blurred vision. Contrast-enhanced magnetic resonance imaging of the brain revealed bilaterally symmetrical diffuse enlargement of the lacrimal glands. A fine needle biopsy of the lacrimal gland was consistent with sarcoidosis. Although, isolated lacrimal gland involvement is rare, it may be the initial clinical presentation of sarcoidosis, as seen in this patient. Imaging plays a vital role in these unsuspected cases and careful evaluation of the lacrimal glands with dedicated thin section, fat suppressed, axial and coronal orbital imaging, may help identify a pathological cause and avoid a delay in diagnosis.

The globe: infection, inflammation, and systemic disease

Infection, inflammation, and systemic diseases affecting the globe encompass a broad range of pathologies which may ultimately lead to progressive vision loss. Clinical symptomatology varies from the inexorably silent progressive visual loss to an acute presentation of ocular pain and/or red eye. Most are diagnosed by clinical ophthalmologic examination with selective use of ultrasound, computed tomography, and magnetic resonance imaging for confirmation of the diagnosis, assessment of disease extent, and signs of associated systemic disease. Knowledge of the differential diagnoses of vision loss, ocular pain, and redness makes imaging analysis of this diverse group of processes more precise.

Emergent neuroimaging of intracranial infection/inflammation

Infectious and inflammatory processes of the intracranial compartment often result in acute clinical presentations. The possible causes are legion. Clues to the diagnosis involve clinical presentation, laboratory analysis, and neuroimaging. This article reviews some of the salient factors in understanding intracranial infection/ inflammation, including pathophysiology and neuroimaging protocols/findings, and provides some examples and a few "pearls and pitfalls."

[Histiocytic disorders with orbital involvement]

The eosinophilic granuloma of bone is the most common type of histiocytic disorder involving the orbital area. Imaging data typically show bony defects with an intra-orbital soft-tissue extension. Surgical debulking is most often required. Rosai-Dorfman disease is commonly associated with uni- or bilateral orbital locations. The other histiocytic disorders are very rare, but some have a poor prognosis such as Erdheim-Chester disease.

Imaging appearance of granulomatous lesions of head and neck

We aim to review the imaging appearance of granulomatous lesions of the head and neck. Granulomatous lesions are seen in different regions of the head and neck and a difficult diagnostic challenge for the radiologist. Infective granulomas may be due to bacterial or fungal agents. Non-infective granulomas are Wegener's granulomatosis, sarcoidosis, amyloidosis, chemical granuloma and reparative giant cell granuloma. Familiarity with the clinical presentation and imaging features of these lesions can suggest diagnosis in some cases. CT and MR imaging demonstrate the exact location, extension and effect on surrounding structures. A thorough knowledge of age, gender, common location, clinical features and imaging appearance of granulomatous lesions are important for diagnosis.

Hepatic, ocular, and cutaneous sarcoidosis

Sarcoid affecting the skin, eye, or liver can be symptomatic of or cause significant morbidity. When disease is sever, alternative therapies may be needed.

Orbital Inflammatory Disease

OBJECTIVES

To familiarize rheumatologists and internists with the signs, symptoms, and management of orbital inflammatory disease (OID).

METHODS

A comprehensive literature review related to OID was performed and reported from the perspectives of rheumatology, ophthalmology, and radiology.

RESULTS

OID is a general term encompassing inflammatory diseases that affect some or all of the structures contained within the orbit external to the globe. Orbital involvement as a part of the initial symptom complex is not uncommon for systemic diseases such as Graves' disease, Wegener's granulomatosis, and sarcoidosis. The management of these and other causes of OID, such as idiopathic orbital inflammation (formerly known as "orbital pseudotumor"), orbital myositis, and Tolosa-Hunt syndrome frequently involves systemic immunosuppression. Before immunosuppression is considered, however, infectious and malignant causes of inflammation must be ruled out.

DISCUSSION

Rheumatologists should be familiar with the differential diagnosis of OID and often need to assist colleagues in ophthalmology and internal medicine with the management of this group of diseases.

Lacrimal fossa lesions: pictorial review of CT and MRI features

A wide range of disease process involve the lacrimal gland/fossa. In this pictorial review, we use histology-proven cases to illustrate conditions that affect the lacrimal gland/fossa. CT and MRI features of neoplastic, inflammatory, infiltrative, and developmental conditions are discussed.

Diverse clinical presentations of orbital sarcoid

PURPOSE

To review the clinical presentation, location, systemic features, management, and natural history of orbital sarcoid.

DESIGN

Retrospective, noncomparative, interventional case series.

METHODS

Twenty patients with sarcoid and sarcoidal reactions of the orbit underwent biopsy, excision of localized mass, and systemic and local treatment at a tertiary referral center. Age, gender, onset, symptoms and signs, characterization of disease process, location, systemic disease, associated systemic features, management, and recurrence of the disease were identified.

RESULTS

Of the 20 patients studied, five were male and 15 were female. The mean age was 50.55 +/- 16.43 years (range, 18 to 77 years). The most common symptom was the presence of a palpable mass, followed by eyelid swelling. Review of the computed tomographic scans revealed four main categories of presentation: lacrimal gland infiltration (n = 11; 55%), orbital mass (n = 4; 20%), optic nerve sheath and dural involvement (n = 4; 20%), and extraocular muscle involvement (n = 1; 5%). Concurrent systemic sarcoidosis discovered after the diagnosis of orbital sarcoid was present in 10 cases (50%). The remaining showed no evidence of systemic disease at follow-up. Angiotensin converting enzyme analysis was performed in 10 cases; in only two (20%) was elevated, and in the remaining eight, it was within normal levels.

CONCLUSIONS

Orbital sarcoid has a diverse clinical presentation varying from lacrimal gland infiltration, soft tissue orbital mass, intraorbital and extraorbital optic nerve sheath and dural involvement, to extraocular muscle involvement. The orbital site most commonly involved was the lacrimal gland.

Magnetic resonance imaging of orbital tumors

This contribution provides an overview of diseases of eye and orbit and their appearance on magnetic resonance imaging. In recent years the diagnosis of eye and orbit pathology has profited significantly from increasingly sophisticated technical developments in the field of tomographic methods. Due to the small size of the examination area the improvement in spatial resolution and soft tissue contrast leads to an increase in image quality. In most clinical questions concerning eye and orbit pathologies magnetic resonance imaging is superior to computed tomography and should be early performed.

Difficulties in the differentiation of chronic inflammatory diseases of the central nervous system--value of cerebrospinal fluid analysis and immunological abnormalities in the diagnosis

OBJECTIVES

A number of neurological syndromes may be evoked by involvement of the nervous system due to systemic diseases such as lupus erythematodes, sarcoidosis, Behçet's disease and Sjögren's syndrome (SS) and may be confounded with another chronic inflammatory disease which is restricted to the central nervous system, e.g. multiple sclerosis (MS). Because of different treatment strategies, it is important to distinguish between these different autoimmune diseases.

RESULTS

Neither clinical signs nor additional analyses such as serological findings or cerebrospinal fluid (CSF) analysis are able to differentiate between the diseases with certainty. Nevertheless, taking all findings together, diagnosis may be possible.

CONCLUSION

Here we compare typical clinical and CSF findings in MS, neurosarcoidosis, neurolupus, neuro-Behçet and nervous system involving SS with special emphasis on those findings allowing differentiation of the respective diseases by reviewing the literature.

The optic nerve: radiologic, clinical, and pathologic evaluation

The radiologic investigation of the optic nerve plays an integral part in the diagnostic evaluation of diverse lesions of the optic pathways including inflammatory diseases, vascular disorders and benign and malignant tumors and these radiologic modalities consist principally of CT and MR imaging and, in vascular lesions, MR angiography and conventional angiography. The selection of radiologic studies and their focus is based on the ophthalmologic examination where the ophthalmologist can often determine the suspected location of lesions in the anterior or posterior visual pathways. Furthermore, inspection of the eye, including adnexal structures and funduscopy, provides additional information in the clinical assessment of these patients. With technical advances in the last few years, CT and MR imaging can detect lesions and determine their location and extent with high sensitivity and specificity. This article discusses the radiologic, clinical, and pathologic evaluation of the optic nerve.

Loss of vision: imaging the visual pathways

This is an overview of diseases presenting with visual impairment, which aims to provide an understanding of the anatomy and pathology of the visual pathways. It discusses the relevant clinical background and neuroimaging findings on CT and standard and advanced MRI of diseases affecting the globe; optic nerve/sheath complex; optic chiasm, tract and radiation; and visual cortex. The overview covers common tumours, trauma, inflammatory and vascular pathology, and conditions such as benign intracranial hypertension and posterior reversible leukoencephalopathy syndrome.

[Differential diagnosis of chronic inflammatory diseases of the central nervous system. Cerebrospinal fluid diagnosis and immunological parameters]

A number of neurological syndromes may be evoked by involvement of the nervous system due to systemic diseases such as lupus erythematosus, sarcoidosis, Behcet's disease, and Sjogren's syndrome. Because of different treatment strategies, it is important to distinguish between these different diseases. Neither clinical signs nor additional analyses such as serological findings or cerebrospinal fluid analysis are able to differentiate between the diseases with certainty. Nevertheless, diagnosis may finally be made taking all findings together. Here we compare typical clinical and cerebrospinal fluid findings in neurosarcoidosis, neurolupus, neuro-Behcet, and nervous system involving Sjogren's syndrome, with special emphasis on those findings allowing differentiation of the respective diseases.

Sarcoidosis of the Anterior Visual Pathway: 24 New Cases

OBJECTIVES

To describe the clinical spectrum and a rational approach to the diagnosis of anterior visual pathway sarcoidosis.

METHODS

Retrospective chart review of all patients examined in neuro-ophthalmic consultation by 1 author from 1989 to 1998 with a diagnosis of sarcoidosis.

RESULTS

There were 24 patients (17 female, 7 male, mean age 40 years) with anterior visual pathway sarcoidosis, 17 (71%) of whom were not previously known to have sarcoidosis. Visual acuity ranged from 20/20 to NLP. Normal fundi were observed in 15%. Among the 85% who had fundus abnormalities, pallor was present in 55%, disc edema in 26%, periphlebitis/sheathing in 14%, and optic disc granuloma in 10%. Ten patients (42%) had uveitis, active in only 3 (13%). An elevated angiotensin-converting enzyme (ACE) was present in 16 (76%) of 21 patients tested; evidence of sarcoidosis on chest radiograph was present in 13 (72%) of 18; gallium scanning was abnormal in 13 (93%) of 14; neuroimaging abnormalities of the optic nerves, chiasm, or tract were present in 16 (70%) of 23; lymphocytic pleocytosis or elevated cerebrospinal fluid protein was identified in 14 (88%) of 16 patients, with both values elevated in 7 (44%) patients. Histologic confirmation was obtained in 13 (81%) of 16 who underwent biopsy; in the remaining patients, diagnosis was based entirely on clinical and laboratory evidence.

CONCLUSIONS

Anterior visual pathway disease may be underrecognized as a presentation of sarcoidosis. Classic fundus findings of periphlebitis and optic granuloma are typically absent. An aggressive diagnostic evaluation may help establish the diagnosis early in its course.

Magnetic resonance imaging and nuclear imaging in sarcoidosis

MRI has become of great importance in the study of several aspects of sarcoidosis. The main development has taken place in the assessment of neurosarcoidosis, but MRI may be also useful in the evaluation of sarcoidosis of the bone, muscle, heart, and intrathoracic. Nuclear imaging in sarcoidosis acquired a great expansion with the introduction of (67)gallium scanning as a marker of activity. Although its current use has decreased, it is still very helpful in particular situations of the disease. Other more recently introduced nuclear imaging techniques may have a role in the evaluation of cardiac sarcoidosis and in the assessment of the extension of the disease.

Neurologic manifestations of sarcoidosis

Sarcoidosis is multisystem granulomatous disease of unknown etiology. Although the nervous system is involved in only 5% to 16% of patients, neurosarcoidosis is one of the more serious manifestations of the disease. Cranial neuropathies are common, but involvement of the mininges or the brain or spinal cord parenchyma causes more severe morbidity. MR imaging of affected portions of the neuraxis is a very sensitive diagnostic technique. Treatment with corticosteroids is the mainstay of therapy.

Comparison of 2D and 3D MRI of the optic and oculomotor nerve anatomy

A total of 30 healthy volunteers underwent magnetic resonance imaging (MRI) with T1 weighted (w.) 3D magnetization prepared rapid gradient echo (MP-RAGE), T2 w. 2D turbo spin echo (TSE) and T2* w. 3D constructive interference in steady state (CISS) sequences to evaluate the detectability of the optic, oculomotor, trochlear and abducens nerves. CISS yielded the best results for the trochlear and abducens nerve, MP-RAGE for the optic chiasm and tract. The optic and oculomotor nerves were very well detectable using both CISS and MP-RAGE without any statistically significant difference between the two.

Orbital involvement as the initial manifestation of sarcoidosis: magnetic resonance imaging findings

A 74-year-old man had diplopia, painful right ophthalmoplegia, proptosis, conjunctival injection, and facial skin lesions. Magnetic resonance imaging (MRI) revealed infiltration of the right intraorbital adipose tissue. Lesions were mixed low- and high-signal on T2-weighted images and enhanced on fat-suppressed T1-weighted postcontrast images. A skin biopsy revealed numerous noncaseating granulomas consistent with sarcoidosis. Treatment with corticosteroids and chlorambucil led to a full clinical recovery. Sarcoidosis should be considered in the evaluation of orbital pseudotumor in elderly patients, even if no systemic manifestations of sarcoidosis are present.

Neurosarcoidosis

Although there continues to be sporadic reporting of small numbers of patients with neurosarcoidosis, relatively little progress is being made in defining this condition in more detail, making it difficult for clinicians to be confident in their diagnoses and treatments. Although groups continue to use retrospective data to extrapolate diagnostic criteria, there is a need for a multinational collaboration to produce a prospective data set that would more adequately inform the diagnostic and therapeutic process for individual clinicians.