Le carcinome rénal à cellules chromophobes : une tumeur rare et de bon pronostic

Résumé :Il existe peu d'études dans la littérature comparant les caractéristiques anatomo-cliniques et évolutives des principales formes histologiques de carcinome rénal. Dans nombre de ces études, les carcinomes rénaux étudiés étaient de grades et de stades différents.Buts de l'étude :L'objet de notre étude était d'examiner les caractéristiques anatomo-cliniques d'une série de carcinome rénaux à cellules chromophobes (CRCCh) et de les comparer à celles des carcinomes rénaux conventionnels (CRC) et des carcinomes rénaux papillaires de type 1 (CRP1), à grade et stade équivalents.Matériel et méthodes :41 CRCCh, 40 CRP1 et 153 CRC ont été examinés en se concentrant sur les paramètres suivants : âge et sexe du patient, taille de la tumeur, stade, grade et caractéristiques histologiques. Les survies globales, survies sans récidive et survies sans métastase de chaque groupe tumoral ont été comparées, à grade et stade équivalents (méthode de Kaplan Meier). Les facteurs pronostiques les plus importants ont été recherchés (modèle de Cox).Résultats :En analyse univariée, le CRCCh est celui qui a le meilleur pronostic en terme de survie globale et de survie sans métastase parmi les tumeurs de grade et de stade équivalents. En analyse multivariée, l'histologie CRC est le facteur pronostique le plus important et le plus défavorable.Conclusion A grade et stade équivalents, le pronostic du CRCCh est sensiblement le même que celui du CRP 1 mais significativement meilleur que celui du CRC, avec lequel il ne doit pas être confondu

Symmetric Groups and Quotient Complexity of Boolean Operations

The quotient complexity of a regular language L is the number of left quotients of L, which is the same as the state complexity of L. Suppose that L and L' are binary regular languages with quotient complexities m and n, and that the transition semigroups of the minimal deterministic automata accepting L and L' are the symmetric groups S_m and S_n of degrees m and n, respectively. Denote by o any binary boolean operation that is not a constant and not a function of one argument only. For m,n >= 2 with (m,n) not in {(2,2),(3,4),(4,3),(4,4)} we prove that the quotient complexity of LoL' is mn if and only either (a) m is not equal to n or (b) m=n and the bases (ordered pairs of generators) of S_m and S_n are not conjugate. For (m,n)\in {(2,2),(3,4),(4,3),(4,4)} we give examples to show that this need not hold. In proving these results we generalize the notion of uniform minimality to direct products of automata. We also establish a non-trivial connection between complexity of boolean operations and group theory

Bilateral Ureteral Stenosis with Hydronephrosis as First Manifestation of Granulomatosis with Polyangiitis (Wegener's Granulomatosis): A Case Report and Review of the Literature.

Ureteral stenosis is a rare manifestation of granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis). We report the case of a 76-year-old woman with progressive renal failure in which bilateral hydronephrosis due to ureteral stenosis was the first manifestation of the disease. Our patient also had renal involvement with pauci-immune crescentic glomerulonephritis associated with high titers of anti-proteinase 3 c-ANCAs, but no involvement of the upper or lower respiratory tract. The hydronephrosis and renal function rapidly improved under immunosuppressive therapy with high-dose corticosteroids and intravenous pulse cyclophosphamide. We reviewed the literature and found only ten other reported cases of granulomatosis with polyangiitis/Wegener's granulomatosis and intrinsic ureteral stenosis: in two cases, the presenting clinical manifestation was unilateral hydronephrosis and in only two others was the hydronephrosis bilateral, but this complication developed during a relapse of the disease. This case emphasizes the importance of including ANCA-related vasculitis in the differential diagnosis of unusual cases of unilateral or bilateral ureteral stenosis

HHV-8-negative multicentric Castleman disease presenting as a crescentic immune complexes membranoproliferative glomerulonephritis.

Multicentric Castleman disease is a rare polyclonal lymphoproliferative disorder mainly associated with two renal manifestations: thrombotic microangiopathy and amyloidosis. Nevertheless, we report here a case of human herpes virus-8 negative multicentric Castleman disease with membranous proliferative glomerulonephritis and extracapillary proliferation. A patient was successfully treated with corticosteroids, anti-CD20 and cyclophosphamide therapy

Re-entrant ventricular tachycardia as a complication of ablation of idiopathic ventricular premature beats from the right outflow tract: a case report.

We report an unusual case of non-sustained ventricular tachycardia (NSVT) from the epicardial part of the right ventricular outflow tract (RVOT). A 37-year-old woman who underwent in 2006 an ablation for idiopathic ventricular premature beats (VPBs) from the RVOT presented with pre-syncopal NSVT in 2016. A cardiac workup showed no coronary disease, normal biventricular function, and no enhancement on cardiac magnetic resonance imaging. A metabolic positron emission tomography scan excluded inflammation. Biopsies revealed normal desmosomal proteins. An endocardial mapping revealed an area of low voltage potential (<0.5 mV) at the antero-septal aspect of the RVOT corresponding to the initial site of ablation from 2006. Activation mapping revealed poor prematurity and pace-mapping showed unsatisfactory morphologies in the RVOT, the left ventricle outflow tract and the right coronary cusp. An epicardial map revealed a low voltage area at the antero-septal aspect of the RVOT with fragmented potentials opposite to the endocardial scar. Pace-mapping demonstrated perfect match. An NSVT was induced and local electrocardiogram showed mid-diastolic potentials. Ablation was applied epicardially and endocardially without any complication. The patient was arrhythmia free at 4-year follow-up. Cardiac workup allowed to exclude specific conditions such as arrhythmogenic cardiomyopathy, tetralogy of Fallot, sarcoidosis, or myocarditis as a cause for NSVT from the RVOT. The epi and endocardial map showed residual scar subsequent to the first ablation which served as substrate for the re-entrant NSVT. This is the first case which describes NSVT from the epicardial RVOT as a complication from a previous endocardial ablation for idiopathic VPB

Software Exclusivity and the Scope of Indirect Network Effects in the U.S. Home Video Game Market

This paper investigates the scope of indirect network effects in the home video game industry. We argue that the increasing prevalence of non-exclusive software gives rise to indirect network effects that exist between users of competing and incompatible hardware platforms. This is because software non-exclusivity, like hardware compatibility, allows a software firm to sell to a market broader than a single platform's installed base, leading to a dependence of any particular platform's software on all firms' installed bases. We look for evidence of these market-wide network effects by estimating a model of hardware demand and software supply. Our software supply equation allows the supply of games for a particular platform to depend not only on the installed base of that platform, but also on the installed base of competing platforms. Our results indicate the presence of both a platform-specific network effect and -in recent years- a cross-platform (or generation-wide) network effect. Our finding that the scope of indirect network effects in this industry has widened suggests one reason that this market, which is often cited as a canonical example of one with strong indirect network effects, is no longer dominated by a single platform

Idiopathic desquamative interstitial pneumonia in a child: a case report.

Desquamative interstitial pneumonia is a rare form of interstitial lung disease in children. Respiratory symptoms appear progressively, are often subtle, and diagnosis is often delayed by a mean of 6 months after onset. High resolution chest computed tomography is the most sensitive imaging technique for demonstrating and identifying interstitial pneumonia. The typical histologic pattern of desquamative interstitial pneumonia, with prominent clustered alveolar macrophages, diffuse reactive alveolar epithelial hyperplasia and globular proteinaceous material, is diagnostic. Desquamative interstitial pneumonia in children can be idiopathic, though it is mostly related to an inborn error of surfactant metabolism. We present the complex clinical course and pathologic findings of a 30-months-old Mauritian and Senegalese girl with idiopathic desquamative interstitial pneumonia and multiple extrapulmonary manifestations. To our knowledge, this is the first case report of desquamative interstitial pneumonia to occur as part of a syndrome with multiple organ involvement. We believe that desquamative interstitial pneumonia is not always associated with mutations of the surfactant proteins, and can still be idiopathic, especially when occurring as part of a syndrome with multiple organ involvement, as described in other interstitial lung diseases