Denosumab, an antibody directed against receptor activator of nuclear factor-κB ligand (RANKL), has recently been introduced in the treatment strategy of giant cell tumor of bone. In this study, we assessed the tumor changes induced by denosumab in a national multicentric series of 35 cases (French Bone Pathology Group network—ResOs). Tissue specimens collected before and after denosumab treatment were investigated for RANKL, H3.3 G34W, p63, and Ki-67 expression, and for H3F3A mutation. These parameters were put in correspondance with clinical and radiologic presentation to identify prognostic factors, and more specifically, predictive markers of an optimal histologic response to denosumab, identified as a ≥50% loss in giant cells with fibrosis and ossification. The main changes in posttreatment specimens showed an induction of ossification (P=2.10−5), an increased fibrosis (P=3.10−5), and a major decrease in giant cells (P=6.10−11). No significant change in mononuclear tumor cell density and in patterns of expression of RANKL (P=0.061) and H3.3 G34W was observed (P=0.061). An optimal histologic response to denosumab treatment was associated with an enhanced progression-free survival (P=0.010 in univariate analyses; P=0.040 in multivariate analyses). The initial number of giant cells was predictive of the histologic response to treatment (P=0.016). In summary, denosumab treatment induced radical changes in the tumor. The histologic response, despite the absence of objective regression of the mononuclear cells, was associated with an enhanced progression-free survival. Greater numbers of giant cells represented the only predictive indication of an optimal histologic response to denosumab treatment.

Anaplastic oligodendroglioma (AO), IDH-mutant and 1p/19q codeleted (IDHmut+/ 1p19qcodel), is a high-grade glioma with only limited prognostic markers. The primary objective of this study was to evaluate, by immunohistochemistry, the prognostic value of two proliferation markers, MCM6 and Ki-67, in a large series of IDHmut+/1p19qcodel AO included in the POLA ("Prise en charge des Oligodendrogliomes Anaplasiques") French national multicenter network. We additionally examined the transcriptome obtained from this series to understand the functional pathways dysregulated with the mRNA overexpression of these two markers. The labeling indices (LI) of MCM6 and Ki-67 were obtained via computer-assisted color image analyses on immunostained AO tissues of the cohort (n = 220). Furthermore, a subgroup of AO (n = 68/220) was used to perform transcriptomic analyses. A high LI of either MCM6 (≥50%) or Ki-67 (≥15%) correlated with shorter overall survival, both in univariate (P = 0.013 and P = 0.004, respectively) and multivariate analyses (P = 0.027; multivariate Cox model including age, mitotic index, MCM6 and Ki-67). MCM6 and Ki-67 LI also correlated with overall survival in an additional retrospective cohort of 30 grade II IDHmut+/1p19qcodel oligodendrogliomas. The prognostic value of MCM6 mRNA level was confirmed in The Cancer Genome Atlas (TCGA) IDHmut+/1p19qcodel gliomas. The transcriptomic approach revealed that high transcriptional expressions of MCM6 and MKI67 were both linked positively with cell cycle progression, DNA replication, mitosis, pro-neural phenotype as well as neurogenesis, and negatively with microglial cell activation, immune response, positive regulation of myelination, oligodendrocyte development, beta-amyloid binding and postsynaptic specialization. In conclusion, the overexpression of MCM6 and/or Ki-67 is independently associated to shorter overall survival in IDHmut+/1p19qcodel AO. These two easy-to-use and cost-effective markers could thus be used concurrently in routine pathology practice. Additionally, the transcriptomic analyses showed that AO with high proliferation index have down-regulated immune response and lower microglial cells activation, and bears pro-neural phenotype.

T-box protein 4 mutation causing pulmonary arterial hypertension and lung diseaseTo the Editor:Pulmonary arterial hypertension (PAH) is a progressive disease mainly characterised by a widespread obstruction of distal pulmonary arteries [1]. Untreated, this disease rapidly leads to right heart failure, then to death [2]. Heritable PAH (hPAH) represents about 30% of PAH cases, and this category includes familial forms with or without identified mutations, and sporadic forms carrying a mutation. The first genetic abnormalities discovered in hPAH were bone morphogenetic protein receptor-2 (BMPR2) mutations. Loss of function of this receptor results in proliferation of vascular smooth muscle cells and selection of endothelial cell clones resistant to apoptosis [3]. Since, several other mutations have been implicated in PAH. Mutation in the T-box protein 4 (TBX4) gene lead to an autosomal-dominant disorder called "small patella syndrome" or "coxopodopatellar syndrome", characterised by patellar aplasia and abnormalities of the feet and pelvis [4]. Recently, TBX4 mutation has been reported in childhood-onset PAH [5] and, more rarely, in adults [6,7].We report a case of a TBX4 mutation carrier presenting PAH but also bronchial and pulmonary parenchymal abnormalities potentially related to this mutation.A 34-year-old woman presented in a tertiary care hospital with a potential diagnosis of severe PAH. She was a former smoker (5 pack-years) and had no medical history. The patient had progressive dyspnoea in New York Heart Association (NYHA) functional class III and she experienced right heart failure 2 months before admission.

Background and Objective: Eosinophilic esophagitis (EoE) is an increasingly recognized childhood disease. Esophageal atresia (EA) is the most frequent congenital malformation of the esophagus. Recently, cases of EoE occurring in patients with EA have been reported, although the exact prevalence of EoE in EA remains unknown. The aim is to investigate the prevalence of EoE among EA in adolescents and to describe these patients' characteristics. Methods: Systematic upper gastrointestinal endoscopies with multistage esophageal biopsies were prospectively performed in 63 adolescents with EA. A standardized form was used to collect clinical and endoscopic data. Diagnosis of EoE was made as !15 intraepithelial eosinophils/high power field, whatever the response on proton pump inhibitors therapy. Results: Six patients (9.5%) presented an EoE (17-100 eosinophils/high power field). An atopic condition was reported more frequently in the eosinophil !15 group than in patients with no EoE (66% vs 16%; P ¼ 0.014). Except for chest pain, symptoms and endoscopic features were similar in patients with EoE and patients with no EoE. Conclusion: In our series of 63 patients born with EA, mainly distal tracheoesophageal fistula, the prevalence of EoE is increased, and therefore should be considered in adolescents with EA.