[IgG4-related disease: A proteiform pathology with frequent chest manifestations]. / Maladie associée aux IgG4 : une maladie protéiforme aux manifestations thoraciques fréquentes.

INTRODUCTION: While IgG4-related disease (IgG4-RD) was initially described in the early 2000s, its polymorphic clinical manifestations were previously reported under different names ; they have in common the presence of IgG4+ oligoclonal plasma cells and fibrosis. STATE OF THE ART: Ruling out certain differential diagnoses, the diagnosis of IgG4-RD is based on a bundle of clinical, biological and histological features. Chest involvement is variable and can affect the mediastinum, bronchi, parenchyma, pleura and/or, more rarely, bones and (pericardium, aorta, coronary…) vascular structures. The most frequent radiological manifestations are peribronchovascular thickening, mediastinal lymphadenopathy, and nodular or interstitial patterns. Pleural involvement and posterior mediastinal fibrosis are less frequent, while thoracic paravertebral tissue thickening is highly specific. Systemic corticosteroids are the cornerstone of treatment. In case of relapse or as frontline therapy in case of risk factors for relapse and/or poor tolerance of corticosteroids), a steroid-sparing agent (most often rituximab) is added, and biannual maintenance infusions are associated with a lower risk of relapse. PERSPECTIVES: An international consensus has recently led to the development of classification criteria that should standardize the diagnostic approach and homogenize the enrolment of patients in epidemiological as well as therapeutic studies. Other treatments are also under evaluation, including biologics targeting T2 inflammation, CD-19 (inebilizumab, obexelimab), SLAMF7 (elotuzumab) surface proteins, Bruton's tyrosine kinase, and the JAK/STAT pathway. CONCLUSIONS: Substantial progress has been made over recent years in understanding IgG4-RD pathophysiology, and personalized patient care seems to be an achievable medium-term goal.

[Pelvic mass in 70 years old patient: Difficult diagnosis of Erdheim-Chester disease]. / Masse pelvienne chez un patient de 70 ans : diagnostic difficile de maladie d'Erdheim-Chester.

Erdheim-Chester disease (EC) is a rare disease that is included in Group L in the 2016 revised classification of Langheransian histiocytoses. This disease may be clinically asymptomatic or manifest as a multi-systemic and life-threatening condition. All organs can be affected but typically there is bone involvement, retroperitoneal fibrosis, pituitary involvement, involvement of large vessels, lung, pleura or central nervous system. We are reporting a 70-year-old patient who, as of 2014, had a pelvic mass with retroperitoneal fibrosis and large vessel vasculitis without a definite diagnosis. Histological and molecular examination of the surgical specimen of the pelvic mass with the discovery of the BRAF V600E mutation provided new elements for the definitive diagnosis of Erdheim-Chester disease. We will describe the clinical, histological and molecular features to be known in EC disease.

La fibrose rétropéritonéale idiopathique.

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of fibro-inflammatory tissue around the aorta entrapping the adjacent structures. RPF can be idiopathic or secondary to many disorders. The physiopathology is unknown but can be part of the spectrum of IgG4 related diseases. Imaging studies and inflammatory markers are essential for initial evaluation and follow-up. Biopsy is usually not recommended. The first line of treatment is corticosteroids associated or not with immunosuppressive drugs. In case of ureteral obstruction with renal failure, ureteral stent placement or nephrostomies are recommended. Initial response to treatment is usually good but relapses are frequent.

[Retroperitoneal fibrosis in adults: Diagnostic approach based on a retrospective multicenter study on 32 cases]. / Fibrose rétropéritonéale de l'adulte : approche diagnostique à partir d'une série rétrospective multicentrique de 32 cas.

INTRODUCTION: Retroperitoneal fibrosis is a rare disease, typically with an insidious and various clinical course. The peak incidence is seen in patients 40 to 60 years of age and mostly in man. The characteristic finding in this disease is a periaortic fibrous mass that often surrounds the ureters. The diagnostic approach remains uncodified. We aimed to determine the different clinical, radiological and biological aspects of retroperitoneal fibrosis. PATIENTS AND METHODS: Retrospective multicenter study of 32 retroperitoneal fibrosis cases hospitalized between 1999 and 2014 in the Internal Medicine Department and Urology Department in the university hospital center Sahloul Sousse. RESULTS: There were 24 men and 8 women with a mean age of 58 years. The lumbar pain is the most common clinical signs (53.1%). An inflammatory syndrome and renal failure were the most common biological signs. The diagnosis was suspected on data from the abdominal ultrasound and confirmed by pelvic CT scan that showed a periaortic fibrous mass that often surrounds the ureters. Histological analysis of a surgical biopsy specimen was performed in only eight cases. CONCLUSION: The most common mode of presentation of retroperitoneal fibrosis remains lumbar pain with renal failure and a high sedimentation rate. Although abdominal ultrasound may contribute to the general evaluation of patients with retroperitoneal fibrosis, CT-scanner is the preferred imaging method. The imaging capability of magnetic resonance and the TEP-scan may facilitate assessment of disease extent. LEVEL OF EVIDENCE: 4.

[Differential diagnosis of aortitis]. / Diagnostics différentiels des aortites inflammatoires.

Aortitis are mainly described in inflammatory disorders such as Takayasu arteritis, giant cell arteritis or Behçet's disease. Aortitis is sometimes qualified as idiopathic. However, differential diagnoses must be searched since they need specific interventions. Infectious aortitis should be ruled out first as its rapid evolution and short-term poor prognosis makes it a therapeutic emergency. Furthermore, rarer differential diagnoses should be known as they require specific care that might sometimes differ from the treatment of inflammatory aortitis, such as retroperitoneal fibrosis mostly idiopathic but also secondary to neoplasia or malignant hemopathies. IgG4 related disease, Erdheim-Chester disease and inflammatory abdominal aortic aneurysm due to atherosclerosis are other differential diagnoses to mention in the presence of aortitis in order to adapt patients' care consequently.

[Retroperitoneal fibrosis in adults: Main characteristics and relevance of the diagnostic procedures based on a retrospective multicenter study on 77 cases]. / Fibrose rétropéritonéale de l'adulte : analyse descriptive et évaluation de la pertinence des examens complémentaires réalisés à visée diagnostique à partir d'une série rétrospective multicentrique de 77 cas.

INTRODUCTION: Retroperitoneal fibrosis (RPF) is a rare disorder characterized by the sheathing of retroperitoneal structures by fibro-inflammatory process. It can be either isolated or associated with an underlying disease or condition. In the absence of consistent and consensual approach, the objective of this study was to assess the relevance of diagnostic tests performed during the diagnostic work-up of RPF. METHODS: Seventy-seven patients were included in this retrospective multicenter study. The diagnosis of RPF was defined by the presence of a thickened circumferential homogeneous tissue unsheathing the infrarenal aorta, excluding peri-aneurysmal fibrosis and a clear evidence of a cancer. RESULTS: In 62 cases (80.5%), the RPF was considered as being primary or "idiopathic". Surgical (n=31) or CT-guided (n=9) biopsies of the RPF were performed in half of the patients showing some fibrotic or non-specific inflammatory lesions in 98% of cases. A bone marrow biopsy was performed in 23 patients leading to diagnosis of low grade B cell non-Hodgkin lymphoma in a single patient who also had a monoclonal gammopathy IgM. The systematic search for autoantibodies or serum tumor markers was of no diagnostic value. CONCLUSIONS: Although the diagnostic procedure was heterogeneous, no cause or associated disease was found in the majority of cases of FRP in this series. In the absence of any clinical or paraclinical evidence suggesting an underlying disease or any atypical features at presentation, a number of non-invasive tests (autoantibodies, tumor markers, bone scintigraphy) and also more invasive diagnostic tests (bone marrow and RPF biopsies) seem of little relevance.

[Idiopathic retroperitoneal fibrosis: a multicentric retrospective study of 30 French cases and follow-up of the renal function]. / Fibrose rétropéritonéale idiopathique : évolution à long terme du pronostic rénal dans une série rétrospective multicentrique de 30 cas.

PURPOSE: Idiopathic retroperitoneal fibrosis (IRF) is an inflammatory disorder, affecting the aorta and the surrounding vessels and tissues. The prognosis is mainly driven by the risks of chronic kidney disease and relapse. Our aim was to assess the prevalence of chronic kidney disease at follow-up. METHODS: We retrospectively reviewed the medical records of patients diagnosed for IRF in Seine-Saint-Denis (France) between 1987 and 2011. We collected informations about presentation, radiologic findings and follow-up. Diagnosis of IRF was confirmed when all the following criteria were met: infiltration of the infrarenal aorta or iliac vessels, absence of aneurysmal dilation, lack of clinical suspicion of malignancy. RESULTS: Thirty patients were identified, with a male/female ratio of 4.9. Mean age was 55±13 years old. The mean creatinine clearance was 66 mL/min/1.73 m(2) and the mean CRP was 45±36 mg/L. In 24 (80%) patients, the location of IRF was periaortic and periiliac. Eleven patients (37%) underwent a diagnostic biopsy, and 14 (47%) required an ureteral procedure. A mean follow-up of 63 months was available for 29 patients: 69% relapsed, 7 developed chronic renal disease (24%), and one died of urinary sepsis. Older age (P=0.023), diabetes (P=0.007), and initial renal insufficiency (P=0.05) were associated with a risk of chronic renal insufficiency. CONCLUSION: The high frequency of relapses and chronic renal disease emphasizes the need of close follow-up in patients diagnosed with IRF.

[Long-term follow-up of a French cohort of retroperitoneal fibrosis]. / Fibrose(s) rétropéritonéale(s) : stratégie diagnostique, pathologies associées et suivi à long terme d'une cohorte française.

PURPOSE: Retroperitoneal fibrosis (RPF) is a rare disease with an expanding etiologic spectrum. We aimed to analyze non-invasive diagnosis strategy, associated disorders, monitoring, treatment and prognosis. METHODS: Retrospective cohort study in a single tertiary center. RESULTS: Eighteen RPF cases (11 males) followed between 1996 and 2009 were reviewed. Blood CRP level was high in all cases before treatment. CT scan, associated or not with MRI or 18-FDG PET-scan, confirmed the diagnosis in 15 patients. Histological analysis of a surgical biopsy specimen was performed in only three cases. Ten patients suffered retroperitoneal fibrosis secondary to systemic vasculitis (granulomatosis with polyangeitis, n=1, Takayasu aortitis, n=2), systemic fibrosis with Riedel thyroiditis (n=1) and atheromatous periaortitis (n=6). Fifteen patients were treated with corticosteroids with a mean treatment duration of 60 months (12-228). Dependency to corticosteroids was recorded in ten patients. Patients with fibrosis related to vasculitis were younger, had a higher CRP level, more frequent corticosteroid dependency and a higher relapse rate. Relapses were successfully treated with steroids. Immunosuppressive treatment was only prescribed in the setting of systemic vasculitis. No patient died, after a 6±2 years follow-up. Late relapses could occur, sometimes years after steroid therapy cessation. CONCLUSION: In our study, RPF occurred as a secondary disorder in 60% of the cases. Disease extension, relapse rate and treatment response varied according to the underlying cause of RPF, pleading for an extensive and systematic initial assessment. Since no death or end-stage renal insufficiency was observed, RPF might be considered as a steroid-sensitive and benign disorder.