Malignant gastrointestinal neuroectodermal tumor (GNET) is a rare soft tissue sarcoma, previously referred to as clear cell sarcoma-like gastrointestinal tumor (CCSLGT) and also commonly reported in the literature as clear cell sarcoma of the gastrointestinal tract (CCS-GI). The current study reports a case of GNET arising in the stomach of a 17-year-old male, who presented with symptoms of fatigue, anemia and low temperature. Examination with positron emission tomography-computed tomography revealed a soft tissue mass in the gastric antrum. Subsequently, radical distal gastric resection was performed, and the mass measured 6.0×4.0×3.5 cm3. Histopathological analysis revealed that the tumor cells were arranged in nests and focally formed fascicular, pseudopapillary, pseudoalveolar and rosette-like growth patterns. Osteoclast-like giant cells were also observed. Immunohistochemically, the tumor cells were positive for S-100 protein, vimentin and BCL-2, and negative for HMB45, Melan-A, CD117, CD34 and CD99. Additionally, the osteoclast-like giant cells were positive for CD68. Fluorescence in situ hybridization demonstrated EWSR1 gene rearrangement. After 10 months of follow-up, no evidence of recurrence or metastasis was observed. As GNET is currently classified differently and under various names in the literature, the information provided by this case study and review is predicted to be useful towards the accurate diagnosis, treatment and prognosis of this rare tumor type.

This is an open access article under the terms of the Creat ive Commo ns Attri bution-NonCo mmercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. AbstractEstrogen-related receptor-α (ERRα) is a nuclear receptor of transcription factor that binds to estrogen responsive elements and estrogen-related responsive elements.Estrogen-related receptor-α is involved in metabolic processes and implicated in the progression and growth of several human malignancies. However, the biologic role and clinical significance of ERRα in gallbladder cancer (GBC) remains to be clarified.Here, we reported that ERRα protein expression was notably higher in GBC tissues than in cholecystitis tissues, and that the aberrantly higher ERRα expression was positively correlated with advanced TNM stage and indicated dismal prognosis of GBC (P < .01). In GBC cell lines NOZ and OCUG, the targeted depletion of ERRα retarded the growth and suppressed the migration and invasive capabilities of GBC cells, and inhibited epithelial-mesenchymal transition by decreasing the expression of mesenchymal markers and elevating the expression of epithelial markers. Moreover, ERRα knockdown inhibited tumor growth in nude mice and led to decreased expression levels of Nectin-4, p-PI3K p85α, and p-AKT. Overexpression of ERRα in the GBC-SD cell line showed exactly the opposite effect. The targeted inhibition of Nectin-4 antagonized GBC cell proliferation and invasion, which were induced by ERRα upregulation. Moreover, Nectin-4 depletion inhibited the ERRα-induced activation of the PI3K/AKT pathway. Chromatin immunoprecipitation analysis and dual-luciferase reporter gene assays showed that ERRα enhanced the transcription of Nectin-4 by binding to the promoter of Nectin-4. In conclusion, our data indicated that ERRα could be a potential target for the genetic treatment of GBC. K E Y W O R D S ERRα, gallbladder cancer, invasion, Nectin-4, proliferation | 1515 WANG et Al.

Solid pseudopapillary tumors (SPTs) are unusual neoplasms that mostly occur in the pancreas, and predominantly affect young women. As a low-grade malignant neoplasm of the exocrine pancreas, they occasionally metastasize, usually to the liver or peritoneum. It has been reported that <1% of SPTs are primary extrapancreatic SPTs. In the present study, we present two rare, but conspicuous extrapancreatic SPTs. Both occurred in young women, and showed good prognoses following surgery. One was a recurrent SPT of the pancreas that metastasized to the ovary, and the other was a distinct primary neoplasm that arose in the retroperitoneal area. The pathological features of the two tumors, including solid and pseudopapillary growth patterns with pale or eosinophilic cytoplasm, were characteristic of SPTs of the pancreas. However, in the case of the metastatic ovarian tumor, focal necrosis and an increased nuclear-to-cytoplasmic ratio were observed. The presence of positive nuclear-cytoplasmic β-catenin, the loss of membranous E-cadherin expression, and a perinuclear punctate CD99 staining pattern on immunohistochemistical analysis, were essential features for diagnosis. The aim of the present study was to compare the morphological and immunohistochemical features of these tumors with those typical of pancreatic SPTs, and to raise awareness that SPTs are able to metastasize to unusual sites, and may also arise as primary tumors outside the pancreas, which may lead to diagnostic dilemmas. Case reports Clinical features Case 1. A 22-year-old woman presented at the Emergency Department of our hospital with sudden abdominal pain; two years previously, the patient had been diagnosed with a pancreatic SPT that had extensively metastasized into the abdominal cavity. A review of her medical history revealed that the patient

Background: Gallbladder cancer (GBC) is the most common malignant tumour of the bile duct with a poor prognosis. The estrogen-related receptor alpha (ERRα) is a nuclear receptor that has been associated with metabolic processes and cancer progression. Increased ERRα has been shown in endocrine-related cancer and non-endocrine-related cancer. Nevertheless, its role in GBC remains unknown. Methods: ERRα expression was analyzed by immunohistochemistry in 59 GBC samples. Its association with clinicopathologic characteristics was evaluated. The effect of ERRα on GBC cell proliferation and invasion was evaluated by loss- or gain-of-function assays in vitro and in vivo. The influence of ERRα on EMT biomarkers, Nectin-4 and PI3K/AKT signaling pathway was detected by western blotting. Inhibition of Nectin-4 was conducted to explore the potential mechanism of ERRα in GBC. Results: Our study reveals increased ERRα expression in GBC tissues vs. non-tumour adjacent tissues. ERRα expression is significantly positively correlated with high TNM stage, high invasion depth and lymph node metastasis, while negatively associated with prognosis. Targeted depletion of ERRα by lentivirus-mediated shRNA decreased cell proliferation in vitro and in vivo. ERRα promoted cancer cell migration and epithelial-mesenchymal transition by regulating the expression of EMT relevant genes. Ectopic expression of ERRα promoted GBC cell growth and invasion in vitro, while inhibiton of Nectin-4 attenuated cell growth and invasion induced by ERRα. Moreover, ERRα overexpression activated the PI3K/AKT signaling pathway while this effect can be blocked by Nectin-4 depletion. Nectin-4 was involved in the oncogenic function of ERRα to activate PI3K/AKT signaling pathway in GBC. Conclusions: ERRα promotes GBC progression via activating PI3K/AKT signaling pathway mediated by Nectin-4. ERRα may be a potential prognostic factor and molecular therapeutic target for GBC.