Sarcoidosis from Head to Toe: What the Radiologist Needs to Know

Alveolar Microlithiasis with Mild Clinical Symptoms But Severe Imaging Findings: A Case Report

Pulmonary alveolar microlithiasis (PAM) is a rare genetic disorder that causes calcium phosphate microliths to form in the alveoli. Symptoms usually appear in a person's third or fourth decade of life. A definitive diagnosis does not always demand a lung biopsy but can be achieved in families with more than one member with PAM and compatible chest imaging. We present the case of a 47-year-old woman referred to us for shortness of breath. Chest imaging revealed bilateral diffuse ground-glass opacities, interlobar fissure calcification, and subpleural linear calcifications, leading to a diagnosis of PAM. Although there is no specific treatment for this condition, early diagnosis can help prevent it from progressing rapidly by avoiding exposure to risk factors.

COVID-19 mRNA vaccine-related myocarditis: A PRISMA systematic review, imaging approach and differential diagnoses

We present a case involving a young individual who developed acute myocarditis on the fourth day following administration of a COVID-19 mRNA vaccine. The patient's condition was managed conservatively, resulting in a favorable outcome. This paper extensively discusses the pathogenesis, clinical manifestations, imaging characteristics of COVID-19 mRNA vaccine-related myocarditis and includes a comprehensive review of pertinent literature. Additionally, a systematic review of COVID-19 mRNA vaccine-related myocarditis, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) principles, is presented. Healthcare professionals should maintain a clinical suspicion for COVID-19 mRNA vaccine-related myocarditis when encountering patients with confirmed myocarditis who have received recent COVID-19 mRNA vaccination, after ruling out other potential causes. The diagnosis of acute myocarditis primarily relies on adherence to the Lake Louise Criteria (LLC) for cardiac magnetic resonance (CMR). Nevertheless, specific CMR features or distinctive patterns indicative of COVID-19 mRNA vaccine-related myocarditis are currently undefined. Among patients with vaccine-related myocarditis, common CMR findings encompass subepicardial late gadolinium enhancement and T2-based myocardial edema, although these findings lack specificity and may resemble other medical conditions. Supportive care involving a short-term regimen of NSAIDs, colchicine, and steroids represents the cornerstone of treatment for this variant of myocarditis, which tends to be self-limiting with favorable short-term prognoses. Timely diagnosis is paramount for optimizing patient care.

High-Risk Sarcoidosis: A Focus on Pulmonary, Cardiac, Hepatic and Renal Advanced Diseases, as Well as on Calcium Metabolism Abnormalities

Although sarcoidosis is generally regarded as a benign condition, approximately 20-30% of patients will develop a chronic and progressive disease. Advanced pulmonary fibrotic sarcoidosis and cardiac involvement are the main contributors to sarcoidosis morbidity and mortality, with failure of the liver and/or kidneys representing additional life-threatening situations. In this review, we discuss diagnosis and treatment of each of these complications and highlight how the integration of clinical, pathological and radiological features may help predict the development of such high-risk situations in sarcoid patients.

Noninfectious Granulomatous Lung Disease: Radiological Findings and Differential Diagnosis

Granulomatous lung diseases (GLDs) are a heterogeneous group of pathological entities that can have different clinical presentations and outcomes. Granulomas are histologically defined as focal aggregations of activated macrophages, Langerhans cells, and lymphocytes, and may form in the lungs when the immune system cannot eliminate a foreign antigen and attempts to barricade it. The diagnosis includes clinical evaluation, laboratory testing, and radiological imaging, which especially consists of high-resolution computed tomography. bronchoalveolar lavage, transbronchial needle aspiration or cryobiopsy, positron emission tomography, while genetic evaluation can improve the diagnostic accuracy. Differential diagnosis is challenging due to the numerous different imaging appearances with which GLDs may manifest. Indeed, GLDs include both infectious and noninfectious, and necrotizing and non-necrotizing granulomatous diseases and the imaging appearance of some GLDs may mimic malignancy, leading to confirmatory biopsy. The purposes of our review are to report the different noninfectious granulomatous entities and to show their various imaging features to help radiologists recognize them properly and make an accurate differential diagnosis.

Imaging Features of Pediatric Sarcoidosis

Sarcoidosis is a granulomatous inflammatory disease of uncertain cause. It occurs most commonly in young and middle-aged adults and less frequently in children; therefore, few data on pediatric sarcoidosis exist in the literature. The diagnosis and management of sarcoidosis remain challenging because of diverse and often nonspecific clinical and imaging findings. In addition, the clinical picture varies widely by age. Prepubertal and adolescent patients often present with adult-like pulmonary disease; however, early-onset sarcoidosis is typically characterized by the triad of arthritis, uveitis, and skin rash. Sarcoidosis is mostly a diagnosis of exclusion made by demonstrating noncaseating granulomas at histopathologic examination in patients with compatible clinical and radiologic findings. Although sarcoidosis often affects the lungs and thoracic lymph nodes, it can involve almost any organ in the body. The most common radiologic manifestation is pulmonary involvement, characterized by mediastinal and bilateral symmetric hilar lymphadenopathies with perilymphatic micronodules. Abdominal involvement is also common in children and often manifests as hepatomegaly, splenomegaly, and abdominal lymph node enlargement. Although neurosarcoidosis and cardiac sarcoidosis are rare, imaging is essential to the diagnosis of central nervous system and cardiac involvement because of the risky biopsy procedure and its low diagnostic yield due to focal involvement. Being familiar with the spectrum of imaging findings of sarcoidosis may aid in appropriate diagnosis and management. ©RSNA, 2023 Test Your Knowledge questions are available in the supplemental material.

Sarcoid dactylitis: A case report of rare presentation of uncommon disease, sarcoidosis-From Ethiopia

We present a rare case of sarcoid dactylitis after an adult female presented with painless swelling of the bilateral hand fingers and toe, with radiographic findings highly characteristic for osseous sarcoidosis and confirmation made by bronchoscopic biopsy of hilar enlarged lymph nodes.

Immune-Mediated Hypertrophic Pachymeningitis and its Mimickers: Magnetic Resonance Imaging Findings

Hypertrophic pachymeningitis (HP) is a rare and chronic inflammatory disorder presenting as localized or diffuse thickening of the dura mater. It can be idiopathic or an unusual manifestation of immune-mediated, infectious, and neoplastic conditions. Although some cases may remain asymptomatic, HP can lead to progressive headaches, cranial nerve palsies, hydrocephalus, and other neurological complications, which makes its recognition a fundamental step for prompt treatment. Regarding the diagnosis workup, enhanced MRI is the most useful imaging method to evaluate dural thickening. This article addresses the MR imaging patterns of immune-mediated HP, including immunoglobulin G4-related disease, neurosarcoidosis, granulomatosis with polyangiitis, rheumatoid pachymeningitis, and idiopathic HP. The main infectious and neoplastic mimicking entities are also discussed with reference to conventional and advanced MR sequences.

Ocular sarcoidosis in adults and children: update on clinical manifestation and diagnosis

Sarcoidosis-associated uveitis, is the predominant ocular sarcoidosis presentation, which affects both adults and children. For adults, international ocular sarcoidosis criteria (IWOS) and sarcoidosis-associated uveitis criteria (SUN) are defined. However, for children they are not yet established internationally. Due to the specificity of pediatric manifestations of sarcoidosis, this task is even more challenging. In children, sarcoidosis is subdivided into Blau syndrome and early-onset sarcoidosis (BS/EOS) affecting younger children (< 5 years) and the one affecting older children with clinical presentation resembling adults. Differential diagnosis, clinical work-up as well as diagnostic criteria should be adapted to each age group. In this article, we review the clinical manifestation of sarcoidosis-associated uveitis in adults and children and the sensitivity and specificity of various ocular sarcoidosis diagnostic modalities, including chest X-ray and CT, FDG PET-CT, gallium-67 scintigraphy, bronchoalveolar lavage fluid, genetic testing for NOD2 mutations and serum biomarkers, such as ACE, lysozyme and IL2R.

Neuroimaging of hypophysitis: etiologies and imaging mimics

Hypophysitis is an inflammatory disease affecting the pituitary gland. Hypophysitis can be classified into multiple types depending on the mechanisms (primary or secondary), histology (lymphocytic, granulomatous, xanthomatous, plasmacytic/IgG4 related, necrotizing, or mixed), and anatomy (adenohypophysitis, infundibulo-neurohypophysitis, or panhypophysitis). An appropriate diagnosis is vital for managing these potentially life-threatening conditions. However, physiological morphological alterations, remnants, and neoplastic and non-neoplastic lesions may masquerade as hypophysitis, both clinically and radiologically. Neuroimaging, as well as imaging findings of other sites of the body, plays a pivotal role in diagnosis. In this article, we will review the types of hypophysitis and summarize clinical and imaging features of both hypophysitis and its mimickers.

Quantitative myocardial T2 mapping adds value to Japanese circulation society diagnostic criteria for active cardiac sarcoidosis

Noninvasive identification of active myocardial inflammation in patients with cardiac sarcoidosis plays a key role in management but remains elusive. T2 mapping is a proposed solution, but the added value of quantitative myocardial T2 mapping for active cardiac sarcoidosis is unknown. Retrospective cohort analysis of 56 sequential patients with biopsy-confirmed extracardiac sarcoidosis who underwent cardiac MRI for myocardial T2 mapping. The presence or absence of active myocardial inflammation in patients with CS was defined using a modified Japanese circulation society criteria within one month of MRI. Myocardial T2 values were obtained for the 16 standard American Heart Association left ventricular segments. The best model was selected using logistic regression. Receiver operating characteristic curves and dominance analysis were used to evaluate the diagnostic performance and variable importance. Of the 56 sarcoidosis patients included, 14 met criteria for active myocardial inflammation. Mean basal T2 value was the best performing model for the diagnosis of active myocardial inflammation in CS patients (pR2 = 0.493, AUC = 0.918, 95% CI 0.835-1). Mean basal T2 value > 50.8 ms was the most accurate threshold (accuracy = 0.911). Mean basal T2 value + JCS criteria was significantly more accurate than JCS criteria alone (AUC = 0.981 vs. 0.887, p = 0.017). Quantitative regional T2 values are independent predictors of active myocardial inflammation in CS and may add additional discriminatory capability to JCS criteria for active disease.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

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.

Differential diagnosis of pulmonary sarcoidosis: a review

Diagnosing pulmonary sarcoidosis raises challenges due to both the absence of a specific diagnostic criterion and the varied presentations capable of mimicking many other conditions. The aim of this review is to help non-sarcoidosis experts establish optimal differential-diagnosis strategies tailored to each situation. Alternative granulomatous diseases that must be ruled out include infections (notably tuberculosis, nontuberculous mycobacterial infections, and histoplasmosis), chronic beryllium disease, hypersensitivity pneumonitis, granulomatous talcosis, drug-induced granulomatosis (notably due to TNF-a antagonists, immune checkpoint inhibitors, targeted therapies, and interferons), immune deficiencies, genetic disorders (Blau syndrome), Crohn's disease, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and malignancy-associated granulomatosis. Ruling out lymphoproliferative disorders may also be very challenging before obtaining typical biopsy specimen. The first step is an assessment of epidemiological factors, notably the incidence of sarcoidosis and of alternative diagnoses; exposure to risk factors (e.g., infectious, occupational, and environmental agents); and exposure to drugs taken for therapeutic or recreational purposes. The clinical history, physical examination and, above all, chest computed tomography indicate which differential diagnoses are most likely, thereby guiding the choice of subsequent investigations (e.g., microbiological investigations, lymphocyte proliferation tests with metals, autoantibody assays, and genetic tests). The goal is to rule out all diagnoses other than sarcoidosis that are consistent with the clinical situation. Chest computed tomography findings, from common to rare and from typical to atypical, are described for sarcoidosis and the alternatives. The pathology of granulomas and associated lesions is discussed and diagnostically helpful stains specified. In some patients, the definite diagnosis may require the continuous gathering of information during follow-up. Diseases that often closely mimic sarcoidosis include chronic beryllium disease and drug-induced granulomatosis. Tuberculosis rarely resembles sarcoidosis but is a leading differential diagnosis in regions of high tuberculosis endemicity.

Mediastinal lymphadenopathy in sarcoidosis: Can diffusion MRI play a role in its evaluation?

Background

Sarcoidosis is a multisystem disease defined by non-caseous epithelioid cell granulomas that can affect virtually all organs. Lung, mediastinal and hilar lymph node involvement is prevalent, occurring in around 90% of the patients, and is responsible for the majority of the morbidity and mortality related to the disorder. Sarcoidosis is one of the differential diagnoses of the benign mediastinal lymphadenopathy. This research aimed to detect the diagnostic value of magnetic resonance imaging (MRI) diffusion in evaluation of mediastinal lymphadenopathy in sarcoid patients.

Results

This cross study involved a total of 30 patients known to have sarcoidosis: 6 males and 24 females aged between 18 and 50 years (with a mean age 38.97 ± 8.67); all of them presented with mediastinal lymphadenopathy. For all patients, each lymph node group was evaluated for the average size and average ADC value. The mean ADC measured was (1.76 ± 0.28) × 10−3 mm2/s. Eight patients showed concurrent activity with poor response to the treatment, and they showed different ADC values with one of them showing low ADC with pattern of diffusion restriction displaying mean ADC value of 1.28 × 10−3 mm2/s.

Conclusions

Diffusion-weighted MRI is an established imaging technique that could be utilized to evaluate mediastinal lymphadenopathy in sarcoidosis as the benign counterpart of mediastinal lymphadenopathy.

FDG PET/CT Imaging of Sarcoidosis

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology. The diagnostic can be made by histological identification of non-caseous granuloma or by a combination of clinical criteria. Active inflammatory granuloma can lead to fibrotic damage. Although 50% of cases resolve spontaneously, systemic treatments are often necessary to decrease symptoms and avoid permanent organ dysfunction, notably in cardiac sarcoidosis. The course of the disease can be punctuated by exacerbations and relapses and the prognostic depends mainly on affected sites and patient management. FDG-PET/CT along with newer FDG-PET/MR have emerged as key imaging modalities in sarcoidosis, namely for certain diagnostic purposes, staging and biopsy guiding. By identifying with a high sensitivity inflammatory active granuloma, FDG hybrid imaging is a main prognostic tool and therapeutic ally in sarcoidosis. This review aims to highlight the actual critical roles of hybrid PET imaging in sarcoidosis and display a brief perspective for the future which appears to include other radiotracers and artificial intelligence applications.

An expert overview of pulmonary fibrosis in sarcoidosis

INTRODUCTION

Advanced pulmonary sarcoidosis refers to phenotypes of pulmonary sarcoidosis that often lead to significant loss of lung function, respiratory failure, or death. Around 20% of patients with sarcoidosis may progress to this state which is mainly driven by advanced pulmonary fibrosis. Advanced fibrosis often presents with associated complications of sarcoidosis including infections, bronchiectasis, and pulmonary hypertension.

AREAS COVERED

This article will focus on the pathogenesis, natural history of disease, diagnosis, and potential treatment options of pulmonary fibrosis in sarcoidosis. In the expert opinion section, we will discuss the prognosis and management of patients with significant disease.

EXPERT OPINION

While some patients with pulmonary sarcoidosis remain stable or improve with anti-inflammatory therapies, others develop pulmonary fibrosis and further complications. Although advanced pulmonary fibrosis is the leading cause of death in sarcoidosis, there are no evidence-based guidelines for the management of fibrotic sarcoidosis. Current recommendations are based on expert consensus and often include multidisciplinary discussions with experts in sarcoidosis, pulmonary hypertension, and lung transplantation to facilitate care for such complex patients. Current works evaluating treatments include the use of antifibrotic therapies for treatment in advanced pulmonary sarcoidosis.

Neuroimaging Patterns of Intracranial Infections: Meningitis, Cerebritis, and Their Complications

Neuroimaging provides rapid, noninvasive visualization of central nervous system infections for optimal diagnosis and management. Generalizable and characteristic imaging patterns help radiologists distinguish different types of intracranial infections including meningitis and cerebritis from a variety of bacterial, viral, fungal, and/or parasitic causes. Here, we describe key radiologic patterns of meningeal enhancement and diffusion restriction through profiles of meningitis, cerebritis, abscess, and ventriculitis. We discuss various imaging modalities and recent diagnostic advances such as deep learning through a survey of intracranial pathogens and their radiographic findings. Moreover, we explore critical complications and differential diagnoses of intracranial infections.

Sarcoid Here, Sarcoid There, Sarcoid Everywhere

Although usually more associated with the lungs, sarcoidosis can have multiple extrapulmonary manifestations. We present a case of a patient with previous biopsy-proven sarcoidosis who was admitted to the hospital secondary to worsening shortness of breath. The patient was found to be positive for Respiratory Syncytial Virus (RSV) which was believed to have exacerbated his pulmonary symptoms. He was treated with IV steroids, nebulizers, and antibiotics which ultimately helped relieve his symptoms. In terms of his sarcoidosis, he was previously treated in the past with steroids in regards to this pathology (which is the mainstay of treatment); while on the regimen, the patient noted his breathing was improved. Of note, he did also have a history of renal cell carcinoma (RCC) status post nephrectomy which was initially evaluated for possible sarcoidosis involvement. This medical therapy could also have been the reason his sarcoidosis did not progress to involve other organs.

The Risk of Sarcoidosis Misdiagnosis and the Harmful Effect of Corticosteroids When the Disease Picture Is Incomplete

Sarcoidosis is a complex granulomatous disease of unknown etiology. Due to the heterogeneity of the disease, the diagnosis remains challenging in many cases, often at the physician's discretion, requiring a thorough and complex investigation. Many other granulomatous diseases have the potential to mimic sarcoidosis, whether infectious, occupational, or autoimmune diseases and starting an unnecessary corticosteroid treatment can worsen the patient's prognosis, leading to side effects that can be harder to treat than the actual disease.

Eosinophilic myocarditis: Case report and brief review of the literature

Eosinophilic myocarditis (EM) is a cardiac manifestation of hypereosinophilic syndrome with a high mortality rate. EM shares imaging features similar to other restrictive cardiopathies, and include patchy intramural late gadolinium enhancement on cardiac magnetic resonance with or without presence of biventricular thrombus. Diagnosis is confirmed on histopathology, and is the current gold standard. Here we report clinical presentation and imaging findings of EM in a 70-year-old woman who presented with fever and chills.

Secondary sclerosing cholangitis: mimics of primary sclerosing cholangitis

Sclerosing cholangitis is a chronic cholestatic disease characterized by stricturing, beading, and obliterative fibrosis of the bile ducts. Sclerosing cholangitis is considered primary (PSC) if no underlying etiology is identified or secondary (SSC) if related to another identifiable cause. In this article, we will review the clinical features, pathogenesis, diagnosis, and imaging findings of PSC and SSC, with an emphasis on features that may aid in the distinction of these entities. We will also discuss various etiologies of SSC including recurrent pyogenic cholangitis, other infectious etiologies, ischemic damage, toxic insults, and immunologic, congenital, and miscellaneous causes, highlighting the unique imaging findings and clinical context of each diagnosis.

Sarcoidosis and COVID-19: At the Cross-Road between Immunopathology and Clinical Manifestation

Coronavirus disease 2019 (COVID-19) has been associated with dysregulation of the immune system featuring inappropriate immune responses, exacerbation of inflammatory responses, and multiple organ dysfunction syndrome in patients with severe disease. Sarcoidosis, also known as Besnier-Boeck-Schaumann disease, is an idiopathic granulomatous multisystem disease characterized by dense epithelioid non-necrotizing lesions with varying degrees of lymphocytic inflammation. These two diseases have similar clinical manifestations and may influence each other at multiple levels, eventually affecting their clinical courses and prognosis. Notably, sarcoidosis patients are at high risk of severe COVID-19 pneumonia because of the underlying lung disease and chronic immunosuppressive treatment. In this narrative review, we will discuss interactions between sarcoidosis and COVID-19 in terms of clinical manifestations, treatment, and pathogenesis, including the role of the dysregulated renin-angiotensin system, altered immune responses involving increased cytokine levels and immune system hyperactivation, and cellular death pathways.

Autoimmune disease of head and neck, imaging, and clinical review

Autoimmune disease of the head and neck (H&N) could be primary or secondary to systemic diseases, medications, or malignancies. Immune-mediated diseases of the H&N are not common in daily practice of radiologists; the diagnosis is frequently delayed because of the non-specific initial presentation and lack of familiarity with some of the specific imaging and clinical features. In this review, we aim to provide a practical diagnostic approach based on the specific radiological findings for each disease. We hope that our review will help radiologists expand their understanding of the spectrum of the discussed disease entities, help them narrow the differential diagnosis, and avoid unnecessary tissue biopsy when appropriate based on the specific clinical scenarios.

The Onset of Sarcoidosis After COVID-19 Vaccination Revealed by the 18 F-FDG PET

ABSTRACT

Sarcoidosis is a heterogeneous multisystem disease characterized by noncaseating granulomas. We presented 18 F-FDG PET/CT findings of sarcoidosis in a previously healthy 43-year-old man who presented intermittent cough after the third dose of COVID-19 vaccination. 18 F-FDG PET/CT showed high uptake of one solitary nodule in the right middle lobe, mediastinal lymph nodes, bilateral hila, and multiple nodules under the right pleura, mimicking the malignancy. Nevertheless, the biopsy confirmed distinct noncaseating granulomas. This case emphasizes the onset of sarcoidosis revealed by 18 F-FDG PET/CT after COVID-19 vaccination.

Röntgenbefunde bei diffusen parenchymatösen Lungenerkrankungen

Klinisches Problem

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Imaging More than Skin-Deep: Radiologic and Dermatologic Presentations of Systemic Disorders

Background: Cutaneous manifestations of systemic diseases are diverse and sometimes precede more serious diseases and symptomatology. Similarly, radiologic imaging plays a key role in early diagnosis and determination of the extent of systemic involvement. Simultaneous awareness of skin and imaging manifestations can help the radiologist to narrow down differential diagnosis even if imaging findings are nonspecific. Aims: To improve diagnostic accuracy and patient care, it is important that clinicians and radiologists be familiar with both cutaneous and radiologic features of various systemic disorders. This article reviews cutaneous manifestations and imaging findings of commonly encountered systemic diseases. Conclusions: Familiarity with the most disease-specific skin lesions help the radiologist pinpoint a specific diagnosis and consequently, in preventing unnecessary invasive workups and contributing to improved patient care.

The position of geochemical variables as causal co-factors of diseases of unknown aetiology

Abstract

The term diseases of unknown aetiology (DUA) or idiopathic diseases is used to describe diseases that are of uncertain or unknown cause or origin. Among plausible geoenvironmental co-factors in causation of DUA, this article focusses on the entry of trace elements, including metals and metalloids into humans, and their involvement in humoral and cellular immune responses, representing potentially toxic agents with implications as co-factors for certain DUA. Several trace elements/metals/metalloids (micronutrients) play vital roles as co-factors for essential enzymes and antioxidant molecules, thus, conferring protection against disease. However, inborn errors of trace element/metal/metalloid metabolisms can occur to produce toxicity, such as when there are basic defects in the element transport mechanism. Ultimately, it is the amount of trace element, metal or metalloid that is taken up, its mode of accumulation in human tissues, and related geomedical attributes such as the chemical form and bioavailability that decisively determine whether the exerted effects are toxic or beneficial. Several case descriptions of DUA that are common worldwide are given to illustrate our knowledge so far of how trace element/metal/metalloid interactions in the immune system may engender its dysregulation and be implicated as causal co-factors of DUA.

Article highlights

The importance of a proper understanding of geochemical perturbations in human metabolisms is emphasisedIt is proferred that such an understanding would aid greatly in the decipherment of diseases of unknown aetiology (DUA)The thesis presented may pave the way towards better diagnosis and therapy of DUA.

Tuberculosis of abdominal lymph nodes, peritoneum, and GI tract: a malignancy mimic

OBJECTIVE

The purpose is to discuss abdominal tuberculosis mimicking malignancy involving the lymph nodes, peritoneum, and the GI tract.

CONCLUSION

Awareness of the pathophysiology and imaging appearance on various modalities of abdominal tuberculosis involving the lymph nodes, peritoneum, and the GI tract that may simulate malignancy can aid differentiation, diagnosis, and therapy, particularly in areas where tuberculosis is endemic.

Comprehensive radiological features of laryngeal sarcoidosis: cases series and systematic review

PURPOSE

To comprehensively summarize the characteristic radiological findings of laryngeal sarcoidosis.

METHODS

We reviewed patients with laryngeal sarcoidosis who underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) and included 8 cases from 8 publications that were found through a systematic review and 6 cases from our institutions. Two board-certified radiologists reviewed and evaluated the radiological images.

RESULTS

Almost all cases exhibited supraglottic lesions 13/14 (92.9%) and most of them involved aryepiglottic folds (12/13, 92.3%), epiglottis (11/14, 78.6%), and arytenoid region (10/14, 71.4%). Most lesions were bilateral (12/14, 85.7%). All cases showed well-defined margins and a diffuse swelling appearance (14/14, 100%). Non-contrast CT revealed a low density (4/5, 80%). The contrast-enhanced CT showed a slight patchy enhancement predominantly at the margin of the lesion in most cases (12/13, 92.3%). In one case, T2-weighted images showed high signal intensity peripherally and low signal intensity centrally (1/1, 100%). Gadolinium-enhanced MRI showed moderate heterogeneous enhancement predominantly at the margin of the lesion (2/2, 100%). In one case, diffusion-weighted imaging showed intermediate signal intensity; the apparent diffusion coefficient value was 2.4 × 10^-3 mm²/s. The larynx was the only region affected by sarcoidosis in 57.1% (8/14) of the cases. Involvement of the neck lymph nodes and distant organs was observed in 4/14 (28.6%) patients, respectively.

CONCLUSION

We summarized the CT and MRI findings of patients with laryngeal sarcoidosis. Knowledge of these characteristics is expected to facilitate prompt diagnosis and appropriate management.

ERRATUM

[This corrects the article doi: 10.36416/1806-3756/e20200595].

[Chest radiography findings in diffuse parenchymal lung diseases]

CLINICAL ISSUE

Diffuse parenchymal lung diseases include a heterogeneous group of diseases of the lung parenchyma, the alveolar spaces, the vessels and the airways, which can be triggered by various pathomechanisms, such as inflammation and fibrotic changes. Since the therapeutic approaches and prognoses differ significantly between the diseases, the correct diagnosis is of fundamental importance. In routine clinical practice, next to the patients' history, the clinical presentation, the laboratory findings and the bronchoscopy, imaging plays a central role in establishing a diagnosis.

PRACTICAL RECOMMENDATIONS

The diagnosis of diffuse parenchymal lung diseases is an enormous challenge for clinicians, radiologists as well as pathologists and should therefore preferably be carried out in a multidisciplinary setting. Since patients often present with unspecific, respiratory symptoms, chest radiographs are the first imaging method used. Many patterns of diffuse parenchymal lung diseases (e.g., ground-glass opacities and consolidations), their distribution (e.g., cranial-caudal) and the presence of additional findings (e.g., mediastinal lymphadenopathy) are often already detectable on chest X‑rays. However, the imaging reference standard and thus, an integral part of the assessment of diffuse parenchymal lung disease, is the chest HR-CT. In some cases, the pattern of the HR-CT is pathognomonic, in others it is unspecific for a disease, so that further diagnostic steps are necessary.

Löfgren Syndrome on 18F-FDG PET/CT: An Acute Manifestation of Sarcoidosis

ABSTRACT

A 58-year-old man presented with fever, erythema nodosum, and arthralgia of knee and ankle joints. Laboratory data showed signs of inflammation, and chest x-ray revealed bilateral hilar lymphadenopathy. 18F-FDG PET/CT was acquired to analyze the underlying causes and revealed FDG accumulation in thoracic lymphadenopathy and in subcutaneous lesions and periarticular uptake. This typical triad is known as Löfgren syndrome, an acute manifestation of sarcoidosis and which, as this case shows, can be visualized on 18F-FDG PET/CT. It is important to recognize this syndrome and to discriminate it from the classic presentation of sarcoidosis because of its different diagnostic and therapeutic consequences.

Consensus statement on thoracic radiology terminology in Portuguese used in Brazil and in Portugal

Effective communication among members of medical teams is an important factor for early and appropriate diagnosis. The terminology used in radiology reports appears in this context as an important link between radiologists and other members of the medical team. Therefore, heterogeneity in the use of terms in reports is an important but little discussed issue. This article is the result of an extensive review of nomenclature in thoracic radiology, including for the first time terms used in X-rays, CT, and MRI, conducted by radiologists from Brazil and Portugal. The objective of this review of medical terminology was to create a standardized language for medical professionals and multidisciplinary teams.

Neurosarcoidosis resembling multiple meningiomas: A misleading presentation of the disease and diagnostic challenge

Sarcoidosis is characterized by the presence of noncaseating granulomatous inflammation in the affected organs. Neurosarcoidosis denotes the involvement of the nervous system and can be either isolated or coexisting with extraneural systemic inflammation. The diagnosis of isolated neurosarcoidosis may be challenging due to unspecific symptoms and similar appearances with other disease processes. This report presents an uncommon case of intracranial sarcoidosis mimicking multiple meningiomas. Familiarity with the spectrum of magnetic resonance imaging findings in neurosarcoidosis is crucial to prevent interpretive errors which may in turn lead to an inappropriate diagnosis and treatment.

A Tale of Two Organ Systems: Imaging review of diseases affecting the thoracic and neurological systems. Part 1

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurological systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated / inflammatory, vascular, syndromic / hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

Non-Infectious Granulomatous Lung Disease: Imaging Findings with Pathologic Correlation

Non-infectious granulomatous lung disease represents a diverse group of disorders characterized by pulmonary opacities associated with granulomatous inflammation, a relatively nonspecific finding commonly encountered by pathologists. Some lesions may present a diagnostic challenge because of nonspecific imaging features; however, recognition of the various imaging manifestations of these disorders in conjunction with patients' clinical history, such as age, symptom onset and duration, immune status, and presence of asthma or cutaneous lesions, is imperative for narrowing the differential diagnosis and determining appropriate management of this rare group of disorders. In this pictorial review, we describe the pathologic findings of various non-infectious granulomatous lung diseases as well as the radiologic features and high-resolution computed tomography imaging features.

Imaging Spectrum of Granulomatous Diseases of the Abdomen and Pelvis

A granuloma is a compact organization of mature macrophages that forms because of persistent antigenic stimulation. At the microscopic level, granulomas can undergo various morphologic changes, ranging from necrosis to fibrosis, which along with other specialized immune cells define the appearance of the granulomatous process. Accordingly, the imaging features of granulomatous diseases vary and can overlap with those of other diseases, such as malignancy, and lead to surgical excisions and biopsy. However, given the heterogeneity of granulomas as a disease group, it is often hard to make a diagnosis on the basis of the histopathologic features of granulomatous diseases alone owing to overlapping microscopic features. Instead, a multidisciplinary approach is often helpful. Radiologists need to be familiar with the salient clinical manifestations and imaging findings of granulomatous diseases to generate an appropriate differential diagnosis. ^©RSNA, 2021.

MRI-based differentiation between lymphoma and sarcoidosis in mediastinal lymph nodes

OBJECTIVE

Evaluation of enlarged mediastinal lymph nodes is crucial for patient management. Malignant lymphoma and sarcoidosis are often difficult to differentiate. Our objective was to determine the diagnostic accuracy of MRI for differentiating between sarcoidosis and malignant lymphoma.

METHODS

This was a retrospective study involving 47 patients who underwent chest MRI and were diagnosed with one of the diseases between 2017 and 2019. T1, T2, and diffusion-weighted signal intensity were measured. Apparent diffusion coefficients (ADCs) and T2 ratios were calculated. The diagnostic performance of MRI was determined by ROC analysis.

RESULTS

Mean T2 ratio was significantly lower in the sarcoidosis group than in the lymphoma group (p = 0.009). The T2-ratio cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 7.1, with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 58.3%, 95.6%, 76.5%, 93.3%, and 68.7%, respectively. The mean ADC was significantly lower in the lymphoma group than in the sarcoidosis group (p = 0.002). The ADC cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 1.205, with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 87.5%, 82.6%, 85.1%, 84.0% and 86.3%, respectively. No significant differences were found between the two groups regarding T1 signal intensity, T2 signal intensity, and lymph node diameter.

CONCLUSIONS

MRI parameters such as ADC, diffusion, and T2 ratio can be useful in the differentiation between sarcoidosis and lymphoma in the evaluation of enlarged lymph nodes.

A Case of Sarcoidosis Mimicking Lymphoma Confounded by Cognitive Decline

Sarcoidosis is a disease with an unknown cause that affects multiple organ systems and has a varied clinical presentation. Often, its symptomatology mimics other disease processes, such as lymphoma, tuberculosis, and amyloidosis. The reticuloendothelial involvement and typical B symptoms of weight loss, fatigue, night sweats, and lymphadenopathy can make sarcoidosis often easily confused with lymphoma. Sarcoidosis has a myriad of central nervous system (CNS) effects, which are often not recognized as symptoms of the disease. These neuropsychiatric symptoms can include, but are not limited to, cognitive decline, headaches, and personality changes. In this report, we discuss a case of a patient who presented with symptoms consistent with indolent lymphoma but was eventually diagnosed with sarcoidosis with extrapulmonary manifestations.

Revisiting the Spleen—An Imaging Review of the Common and Uncommon Splenic Pathology

The spleen is the largest lymphatic organ and is responsible for both hematological and immunological functions. Several common etiologies such as trauma, developmental variants, infectious/inflammatory conditions, and benign and malignant lesions can occur in the spleen. The role of imaging modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in diagnosing these conditions continues to evolve. The main objective of this review article is to illustrate the role of imaging in identifying the common and uncommon pathology of the spleen.

Sarcoidosis Mimicking Primary Pulmonary Artery Sarcoma

ABSTRACT

A 71-year-old man with coronary artery disease, sarcoid uveitis, and recurrent ventricular tachycardia treated with implantable cardioverter-defibrillator presented with increasing dyspnea for several months. Echocardiography showed a large echogenic mass causing severe narrowing of the proximal main pulmonary artery and a resultant gradient of 65 mm Hg. Ventilation-perfusion scintigraphy showed diffusely decreased perfusion of the left lung and an additional mismatched segmental perfusion defect in the left upper lobe. Cardiac MRI could not be performed because of the implantable cardioverter-defibrillator.

Spectrum of [18F]FDG-PET/CT Findings in Benign Lymph Node Pathology

Diffuse lymphadenopathy has a long differential diagnosis that includes both malignant and benign causes. As part of the lymphadenopathy work-up, many patients undergo [¹⁸F]FDG-PET/CT for purposes of ruling out malignancy. FDG-avid lymph nodes, however, are not specific for malignancy. This review will illustrate the spectrum of nodal findings on FDG-PET/CT with correlation to other cross-sectional imaging and clinical history in patients with representative infectious, inflammatory, and benign lymphoproliferative disorders. These findings are important for the nuclear medicine radiologist to understand, as they can represent common pitfalls in the work-up of lymphadenopathy. While FDG-PET/CT may be limited in ascertaining a definitive diagnosis in a disease process as the cause of lymphadenopathy, it can help to narrow this differential and rule out certain diseases in the correct clinical context.