Aberrant Lipid Metabolism in Macrophages Is Associated with Granuloma Formation in Sarcoidosis.

Rationale: Chronic sarcoidosis is a complex granulomatous disease with limited treatment options that can progress over time. Understanding the molecular pathways contributing to disease would aid in new therapeutic development. Objectives: To understand whether macrophages from patients with nonresolving chronic sarcoidosis are predisposed to macrophage aggregation and granuloma formation and whether modulation of the underlying molecular pathways influence sarcoidosis granuloma formation. Methods: Macrophages were cultivated in vitro from isolated peripheral blood CD14+ monocytes and evaluated for spontaneous aggregation. Transcriptomics analyses and phenotypic and drug inhibitory experiments were performed on these monocyte-derived macrophages. Human skin biopsies from patients with sarcoidosis and a myeloid Tsc2-specific sarcoidosis mouse model were analyzed for validatory experiments. Measurements and Main Results: Monocyte-derived macrophages from patients with chronic sarcoidosis spontaneously formed extensive granulomas in vitro compared with healthy control participants. Transcriptomic analyses separated healthy and sarcoidosis macrophages and identified an enrichment in lipid metabolic processes. In vitro patient granulomas, sarcoidosis mouse model granulomas, and those directly analyzed from lesional patient skin expressed an aberrant lipid metabolism profile and contained increased neutral lipids. Conversely, a combination of statins and cholesterol-reducing agents reduced granuloma formation both in vitro and in vivo in a sarcoidosis mouse model. Conclusions: Together, our findings show that altered lipid metabolism in sarcoidosis macrophages is associated with its predisposition to granuloma formation and suggest cholesterol-reducing therapies as a treatment option in patients.

Hydroxychloroquine Therapy in Sarcoidosis-Associated Uveitis.

BACKGROUND/PURPOSE: To assess the efficacy and tolerance of hydroxychloroquine in sarcoidosis-associated uveitis. METHODS: Retrospective study on all patients with sarcoidosis-associated uveitis who were treated with hydroxychloroquine between 2003 and 2019 in a French university hospital. RESULTS: Twenty-seven patients with sarcoidosis-associated uveitis received hydroxychloroquine. The mean duration of treatment was 20.0 ± 10.9 months. At the end of the follow-up, hydroxychloroquine success was achieved in 15 (55.6%) patients. Four of them were also on oral corticosteroids, with a prednisone dose ≤5 mg/day. Under treatment, the median prednisone dose decreased from 20.0 (interquartile range (IQR), 7-25) to 5.0 (IQR, 3-6.5) mg/day (p = .02). The incidence rate of flare decreased from 204.6 to 63.8 per 100 person-years (p = .02). Hydroxychloroquine was discontinued in 12 (44.4%) patients during follow-up, including 8 (29.6%) for ineffectiveness, and three who experienced side effects. CONCLUSION: Hydroxychloroquine appears as an interesting option in sarcoidosis-associated uveitis.Abbreviations: AZA: Azathioprine; BAL: Bronchoalveolar Lavage; BCVA: Best-Corrected Visual Acuity; ENT: Ears, Nose and Throat; HCQ: Hydroxychloroquine; IOP: Intra-Ocular Pressure; IQR: interquartile range; MHC: Major Histocompatibility Complex; MMF: Mycophenolate Mofetil; MTX: Methotrexate; PMSI: Programme de Médicalisation du Système d'Information; SAU: Sarcoidosis-Associated Uveitis; SD: Standard Deviation; SUN: Standard Uveitis Nomenclature.

Value of Chest X-Ray and Chest Computed Tomography for Systemic Sarcoidosis Diagnosis in Undifferentiated Uveitis.

BACKGROUND: To evaluate the contribution of chest X-ray and chest CT for the diagnosis of sarcoid uveitis. METHODS: Retrospective study on consecutive patients with uveitis of unknown etiology, who underwent both chest X-ray and CT during uveitis diagnosis workup in a tertiary French university hospital. RESULTS: A total of 914 patients were included. Systemic sarcoidosis was identified in 23.1%. The probability of discordance between chest X-ray and CT increased with age at diagnosis (p < 0.001). In patients 30 years of age and younger, the probability of discordance was 5% or less, and 0.8% if the ACE level was normal. After 78.3 years of age, the probability of discordance was 20% or more. CONCLUSION: We recommend not to perform CT in patients under 30 years of age with a normal chest X ray and ACE level, and suggest performing chest CT first in the elderly.

Aging is associated with impaired triggering of TRPV3-mediated cutaneous vasodilation: a crucial process for local heat exposure.

Sensing temperature is vitally important to adapt our body to environmental changes. Local warm detection is required to initiate regulation of cutaneous blood flow, which is part of the peripheral thermoregulatory mechanisms, and thus avoid damage to surrounding tissues. The mechanisms mediating cutaneous vasodilation during local heat stress are impaired with aging. However, the impact of aging on the ability of the skin to detect subtle thermal changes is unknown. Among heat-activated cation channels, transient receptor potential vanilloid 3 (TRPV3) is a thermo-sensor predominantly expressed on keratinocytes and involved in local vascular thermoregulatory mechanisms of the skin in young mice. In the present study, using a murine in vivo model of local heat exposure of the skin, we showed that heat-induced vasodilation was reduced in old mice associated with reduced expression of TRPV3 channels. We also found a decrease in expression and activity of TRPV3 channel, as well as reduced TRPV3-dependent adenosine tri-phosphate release in human primary keratinocytes from old donors. This study shows that aging alters the epidermal TRPV3 channels, which might delay the detection of changes in skin temperature, thereby limiting the mechanisms triggered for local vascular thermoregulation in the old skin.

Diagnostic value of elevated serum angiotensin-converting enzyme and lymphopenia in patients with granulomatous hepatitis.

BACKGROUND AND AIM: Granulomatous hepatitis (GH) is associated with various aetiologies, especially inflammatory and infectious disorders. Sarcoidosis is a granulomatous disease in which the liver is the fourth most affected organ. Since epithelioid cell granulomas are not specific to sarcoidosis and since most patients with hepatic sarcoidosis are asymptomatic, valuable diagnostic biomarkers are needed to support the diagnosis of sarcoidosis. This study proposes to assess the diagnostic value of serum angiotensin converting enzyme (sACE) and lymphopenia in GH for sarcoidosis. METHODS: We retrospectively analyzed the records of 90 patients referred to the internal medicine or hepatogastroenterology departments of the Lyon University Hospital (Lyon, France) between March 2002 and January 2020 in a context of GH. RESULTS: In our tertiary center, 38 patients with sarcoidosis were identified among 73 patients with GH. Lymphopenia had a high specificity (85.7%), which increased when combined with elevated (97.0%). Interestingly, specificity increased in patients under 50 years old (100%). CONCLUSIONS: Those results suggests that lymphopenia and sACE may be valuable biomarkers for sarcoidosis diagnosis in GH when combined, especially in younger patients.

Whole exome sequencing of a German sarcoidosis family with four affected and one spontaneous remission case.

OBJECTIVES: To analyze genetic mechanisms triggering familial sarcoidosis, whole exome screening of a family of six persons with four cases of sarcoidosis and two healthy controls was performed integrating progressive and spontaneous remission cases and evaluating involved genetic alterations that could potentially determine the individual course of the disease. METHODS: Clinical diagnosis criteria in patients of the selected sarcoidosis family were according to American Thoracic Society/European Respiratory Society/World Association of Sarcoidosis and other Granulomatous Disorders guidelines [1]. Exome screening of four patients and the two intrafamilial healthy relatives was performed by a paired-end (2 × 100 bp) sequencing using a NovaSeq 6000 (Illumina, San Diego, CA). We then selected the gene variants considered pathogenic on the basis of a series of prediction software and present only in subjects affected by sarcoidosis of the family, after subtracting the common variations observed in healthy subjects. RESULTS: Four persons out of six family members were affected by sarcoidosis. 50 genes with uncommon in silico pathogenic variants could be identified that differentiated affected and healthy family members. One patient with sarcoidosis showed spontaneous remission whereas the remaining three patients required immunosuppressive treatment. Subtraction analysis revealed 18 genes that distinguished the three progressive cases from the patient with spontaneous remission. CONCLUSION: The genetic analysis of these cases with familial sarcoidosis identified several involved genes and functional pathways that could help to understand the basic mechanisms that determine the development of the disease and that discriminate spontaneously regressive and progressive forms.

Sarcoidosis-Related Uveitis: A Review.

Sarcoidosis is an inflammatory disease that involves the eyes in 10-55% of cases, sometimes without systemic involvement. All eye structures can be affected, but uveitis is the most common ocular manifestation and causes vision loss. The typical ophthalmological appearance of these uveitis is granulomatous (in cases with anterior involvement), which are usually bilateral and with synechiae. Posterior involvement includes vitritis, vasculitis and choroidal lesions. Tuberculosis is a classic differential diagnosis to be wary of, especially in people who have spent time in endemic areas. The diagnosis is based on histology with the presence of non-caseating epithelioid granulomas. However, due to the technical difficulty and yield of biopsies, the diagnosis of ocular sarcoidosis is often based on clinico-radiological features. The international criteria for the diagnosis of ocular sarcoidosis have recently been revised. Corticosteroids remain the first-line treatment for sarcoidosis, but up to 30% of patients require high doses, justifying the use of corticosteroid-sparing treatments. In these cases, immunosuppressive treatments such as methotrexate may be introduced. More recent biotherapies such as anti-TNF are also very effective (as they are in other non-infectious uveitis etiologies).

The Spectrum of Still's Disease: A Comparative Analysis of Phenotypic Forms in a Cohort of 238 Patients.

Still's disease (SD) is a heterogeneous autoinflammatory disorder for which several phenotypes have been described. We conducted a retrospective study to re-evaluate the dichotomous view of the disease, to compare the juvenile and adult forms, and to look for prognostic factors. We collected data from ten French centers, seeking patients with a diagnosis of adult-onset SD (AOSD) or systemic juvenile idiopathic arthritis (sJIA). We identified 238 patients, 152 (64%) of whom had AOSD while 86 (36%) had sJIA. The median age at SD onset was 26.6 years. In patients with identifiable patterns, the course of SD was systemic in 159 patients (74%), chronic in 55 (26%). Sore throat and myalgia were more frequent in patients with AOSD. Abnormal liver tests, serum ferritin and C-reactive protein levels were higher in AOSD group. Fever and skin rash were predictive of complete remission or recovery and high lactate dehydrogenase level was a poor prognosis factor. Symptoms such as splenomegaly, skin rash, high polymorphonuclear neutrophils count and macrophage activation syndrome were predictive of a systemic phenotype. Overall, there were no major differences between sJIA and AOSD. Our results are consistent with the "biphasic" model of an autoinflammatory disease that can progress to chronic arthritis if not treated early.

Management of Non-Infectious Uveitis, a Selection of Topical Items Updating.

First of all, we would like to thank all of the authors for their contributions and the editorial staff who enabled the achievement of this «Diagnosis and Management of Non-infectious Uveitis: Old and New Challenges¼ Special Issue [...].

Diagnosing Hemophagocytic Lymphohistiocytosis with Machine Learning: A Proof of Concept.

Hemophagocytic lymphohistiocytosis is a hyperinflammatory syndrome characterized by uncontrolled activation of immune cells and mediators. Two diagnostic tools are widely used in clinical practice: the HLH-2004 criteria and the Hscore. Despite their good diagnostic performance, these scores were constructed after a selection of variables based on expert consensus. We propose here a machine learning approach to build a classification model for HLH in a cohort of patients selected by glycosylated ferritin dosage in our tertiary center in Lyon, France. On a dataset of 207 adult patients with 26 variables, our model showed good overall diagnostic performances with a sensitivity of 71.4% and high specificity, and positive and negative predictive values which were 100%, 100%, and 96.9%, respectively. Although generalization is difficult on a selected population, this is the first study to date to provide a machine-learning model for HLH detection. Further studies will be required to improve the machine learning model performances with a large number of HLH cases and with appropriate controls.

Evaluation of Glycosylated Ferritin in Adult-Onset Still's Disease and Differential Diagnoses.

Glycosylated ferritin (GF) has been reported as a good diagnostic biomarker for adult-onset Still's disease (AOSD), but only a few studies have validated its performance. We performed a retrospective study of all adult patients with at least one GF measurement over a 2-year period in one hospital laboratory. The diagnosis of AOSD was based on the expert opinion of the treating physician and validated by two independent investigators. Patients' characteristics, disease activity, and outcome were recorded and compared. Twenty-eight AOSD and 203 controls were identified. Compared to controls, the mean GF was significantly lower (22.3% vs. 39.3, p < 0.001) in AOSD patients. GF had a high diagnostic accuracy for AOSD, independent of disease activity or total serum ferritin (AUC: 0.674 to 0.915). The GF optimal cut-off value for AOSD diagnosis was 16%, yielding a specificity of 89% and a sensitivity of 63%. We propose a modified diagnostic score for AOSD, based on Fautrel's criteria but with a GF threshold of 16% that provides greater specificity and increases the positive predictive value by nearly 5 points. GF is useful for ruling out differential diagnoses and as an appropriate classification criterion for use in AOSD clinical trials.

Extreme Hyperferritinemia: Causes and Prognosis.

The significance of extreme hyperferritinemia and its association with certain diagnoses and prognoses are not well characterized. We performed a retrospective analysis of adult patients with at least one total serum ferritin (TSF) measurement ≥ 5000 µg/L over 2 years, in three university hospitals. Conditions associated with hyperferritinemia were collected, and patients were classified into 10 etiological groups. Intensive care unit (ICU) transfer and mortality rates were recorded. A total of 495 patients were identified, of which 56% had a TSF level between 5000 and 10,000 µg/L. There were multiple underlying causes in 81% of the patients. The most common causes were infections (38%), hemophagocytic lymphohistiocytosis (HLH, 18%), and acute hepatitis (14%). For TSF levels > 10,000 µg/L, there were no solid cancer or hematological malignancy without another cause of hyperferritinemia. Isolated iron-overload syndromes never exceeded TSF levels > 15,000 µg/L. Extreme hyperferritinemia (TSF levels > 25,000 µg/L) was associated with only four causes: HLH, infections, acute hepatitis and cytokine release syndromes. A total of 32% of patients were transferred to an ICU, and 28% died. Both ICU transfer rate and mortality were statistically associated with ferritin levels. An optimized threshold of 13,405 µg/L was the best predictor for the diagnosis of HLH, with a sensitivity of 76.4% and a specificity of 79.3%. Hyperferritinemia reflects a variety of conditions, but only four causes are associated with extreme hyperferritinemia, in which HLH and acute hepatitis are the most common. Extreme hyperferritinemia has a poor prognosis with increased mortality.

Identification of Multidimensional Phenotypes Using Cluster Analysis in Sarcoid Uveitis Patients.

PURPOSE: To identify multidimensional phenotypes of sarcoid uveitis patients. DESIGN: Retrospective cohort. METHODS: Consecutive patients with biopsy-proven, presumed, or probable sarcoid uveitis between December 2003 and December 2020 in Lyon were recruited. Data were collected from the clinical notes, and consisted in laboratory and imaging findings, systemic treatments and outcome. Systemic sarcoidosis was diagnosed according to the Abad's modified criteria and uveitis was classified according to the Standardization of Uveitis Nomenclature. A hierarchical cluster analysis was performed. The main outcome measure was identification of different phenotypes of sarcoid uveitis patients. RESULTS: A total of 299 patients were included. Three clusters were identified: (1) younger non-Caucasian patients who presented acute (75.3%), anterior (55.6%) uveitis, and systemic manifestations (87.8%), requiring oral corticosteroids (75.3%) along with immunosuppressive therapy (17.2%) and who were more prone to experience complete visual recovery (84.1%); (2) middle-aged Caucasian patients who presented chronic (91.7%), panuveitis (79.5%), and isolated uveitis at diagnosis (74.8%), requiring systemic treatment with corticosteroids (74.0%) but less frequently immunosuppressive therapy (9.8%) and a worse prognosis (45.3% complete visual recovery); and (3) middle-aged Caucasian patients, without preferential chronic or acute uveitis, isolated uveitis at diagnosis (81.4%), more homogenous in terms of eye involvement repartition, requiring less corticosteroids or immunosuppressive therapy (respectively 54.1% and 13.1%) and having a prognosis close to cluster 2 patients (55.3% complete visual recovery). CONCLUSIONS: This retrospective study suggested the existence of several phenotypes of sarcoid uveitis patients with different progressions and prognoses. Further studies are needed to determine the genetic and environmental factors that could explain these results.

Challenging Mimickers in the Diagnosis of Sarcoidosis: A Case Study.

Sarcoidosis is a systemic granulomatous disease of unknown cause characterized by a wide variety of presentations. Its diagnosis is based on three major criteria: a clinical presentation compatible with sarcoidosis, the presence of non-necrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. Many conditions may mimic a sarcoid-like granulomatous reaction. These conditions include infections, neoplasms, immunodeficiencies, and drug-induced diseases. Moreover, patients with sarcoidosis are at risk of developing opportunistic infections or lymphoma. Reliably confirming the diagnosis of sarcoidosis and better identifying new events are major clinical problems in daily practice. To address such issues, we present seven emblematic cases, seen in our department, over a ten-year period along with a literature review about case reports of conditions misdiagnosed as sarcoidosis.

Autophagy and Mitophagy-Related Pathways at the Crossroads of Genetic Pathways Involved in Familial Sarcoidosis and Host-Pathogen Interactions Induced by Coronaviruses.

Sarcoidosis is a multisystem disease characterized by the development and accumulation of granulomas, the hallmark of an inflammatory process induced by environmental and/or infectious and or genetic factors. This auto-inflammatory disease mainly affects the lungs, the gateway to environmental aggressions and viral infections. We have shown previously that genetic predisposition to sarcoidosis occurring in familial cases is related to a large spectrum of pathogenic variants with, however, a clustering around mTOR (mammalian Target Of Rapamycin)-related pathways and autophagy regulation. The context of the COVID-19 pandemic led us to evaluate whether such genetic defects may increase the risk of a severe course of SARS-CoV2 infection in patients with sarcoidosis. We extended a whole exome screening to 13 families predisposed to sarcoidosis and crossed the genes sharing mutations with the list of genes involved in the SARS-CoV2 host-pathogen protein-protein interactome. A similar analysis protocol was applied to a series of 100 healthy individuals. Using ENRICH.R, a comprehensive gene set enrichment web server, we identified the functional pathways represented in the set of genes carrying deleterious mutations and confirmed the overrepresentation of autophagy- and mitophagy-related functions in familial cases of sarcoidosis. The same protocol was applied to the set of genes common to sarcoidosis and the SARS-CoV2-host interactome and found a significant enrichment of genes related to mitochondrial factors involved in autophagy, mitophagy, and RIG-I-like (Retinoic Acid Inducible Gene 1) Receptor antiviral response signaling. From these results, we discuss the hypothesis according to which sarcoidosis is a model for studying genetic abnormalities associated with host response to viral infections as a consequence of defects in autophagy and mitophagy processes.

Sarcoidosis: A Clinical Overview from Symptoms to Diagnosis.

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

Uveitis as an Open Window to Systemic Inflammatory Diseases.

Spondyloarthritis (Spa), Behçet's disease (BD) and sarcoidosis are major systemic inflammatory diseases worldwide. They are all multisystem pathologies and share a possible ocular involvement, especially uveitis. We hereby describe selected cases who were referred by ophthalmologists to our internal medicine department for unexplained uveitis. Physical examination and/or the use of laboratory and imaging investigations allowed to make a diagnosis of a systemic inflammatory disease in a large proportion of patients. In our tertiary referral center, 75 patients have been diagnosed with Spa (n = 20), BD (n = 9), or sarcoidosis (n = 46) in the last two years. There was a significant delay in the diagnosis of Spa-associated uveitis. Screening strategies using Human Leukocyte Antigen (HLA)-B27 determination and sacroiliac magnetic resonance imaging in patients suffering from chronic low back pain and/or psoriasis helped in the diagnosis. BD's uveitis affects young people from both sexes and all origins and usually presents with panuveitis and retinal vasculitis. The high proportion of sarcoidosis in our population is explained by the use of chest computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography CT that helped to identify smaller hilar or mediastinal involvement and allowed to further investigate those patients, especially in the elderly. Our results confirm how in these sight- and potentially life-threatening diseases a prompt diagnosis is mandatory and benefits from a multidisciplinary approach.

Detection and Prediction of Macrophage Activation Syndrome in Still's Disease.

Distinguishing between macrophage activation syndrome (MAS) and a simple flare of Still's disease (SD) may be challenging. We sought to clarify the clinical features and outcome of MAS in SD and to explore predictive factors of MAS development. Demographic and clinical data, treatments, and outcomes were recorded in a cohort of 206 SD patients. SD patients with and without MAS were compared. To explore predictive factors for the development of MAS, patients were compared at the time of SD diagnosis. Twenty (9.7%) patients experienced MAS, which was inaugural in 12 cases. Patients with MAS were more likely to have hepatomegaly (OR, 3.71; 95% CI, 1.14-11.2; p = 0.03) and neurological symptoms (OR, 4.43; 95% CI, 1.08-15.3; p = 0.04) than patients without MAS. Cytopenias, abnormal liver tests, and coagulation disorders were significantly more frequent in patients with MAS; lactate dehydrogenase and serum ferritin levels were significantly higher. An optimized threshold of 3500 µg/L for serum ferritin yielded a sensitivity (Se) of 85% and a negative predictive value (NPV) of 97% for identifying patients with/without MAS. Survival analysis showed that a high ferritin level at the time of SD diagnosis was predictive of MAS development (p < 0.001). Specific factors, including neurological symptoms, cytopenias, elevated LDH, and coagulopathy, may contribute to the early detection of MAS. Extreme hyperferritinemia at the onset of SD is a prognostic factor for the development of MAS.

State of the art: approved and emerging JAK inhibitors for rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis (RA) is the most common autoimmune inflammatory arthritis in adults. In the past decade, many treatments have emerged to expand the therapeutic armamentarium of rheumatologists. Among emerging treatments, Janus Kinase inhibitors (JAKi) are promising in treating RA and several other inflammatory conditions, such as psoriatic arthritis (PsA). The JAK/STAT signaling pathway is located downstream certain cytokines receptors that are known to be involved in RA pathogenesis. So far, three JAKi are approved for the treatment of RA, while other JAKi, are under investigation. AREAS COVERED: Herein, the authors review those JAKi approved and emerging for the treatment of RA and provide their expert perspectives on the subject area. EXPERT OPINION: JAKi represent an interesting alternative to other DMARDs when MTX has failed. Long-term extension studies are still ongoing, but one can assume that most of the major safety concerns have already come out. Switching from one JAKi to another DMARD has been little studied, but in such cases, preferring a treatment which does not interfere with the JAK/STAT pathway seems to be a reasonable choice.

Sarcoidosis and Cancer: A Complex Relationship.

Sarcoidosis is a systemic disease of unknown etiology, characterized by the presence of non-caseating granulomas in various organs, mainly the lungs, and the lymphatic system. Since the individualization of sarcoidosis-lymphoma association by Brincker et al., the relationship between sarcoidosis or granulomatous syndromes and malignancies has been clarified through observational studies worldwide. Two recent meta-analyses showed an increased risk of neoplasia in sarcoidosis. The granulomatosis can also reveal malignancy, either solid or hematological, defining paraneoplastic sarcoidosis. Recent cancer immunotherapies, including immune checkpoint inhibitors (targeting PD-1, PD-L1, or CTLA-4) and BRAF or MEK inhibitors were also reported as possible inducers of sarcoidosis-like reactions. Sarcoidosis and neoplasia, especially lymphoma, can show overlapping presentations, thus making the diagnosis and treatment harder to deal with. There are currently no formal recommendations to guide the differential diagnosis workup between the evolution of lymphoma or a solid cancer and a granulomatous reaction associated with neoplasia. Thus, in atypical presentations (e.g., deeply impaired condition, compressive lymphadenopathy, atypical localization, unexplained worsening lymphadenopathy, or splenomegaly), and treatment-resistant disease, targeted biopsies on suspect localizations with histological examination could help the clinician to differentiate neoplasia from sarcoidosis. Pathological diagnosis could sometimes be challenging since very few tumor cells may be surrounded by massive granulomatous reaction. The sensitization of currently available diagnostic tools should improve the diagnostic accuracy, such as the use of more "cancer-specific" radioactive tracers coupled with Positron Emission Tomography scan.