title: Primary malignant neuroectodermal tumor of the ileum with predominantly uncommon pseudopapillary architecture.
abstract: A malignant gastrointestinal neuroectodermal tumor (GNET), a distinctive entity covering the characteristics of clear cell sarcoma (CCS) of gastrointestinal tract described recently, arising primarily in the ileum of a 33-year-old woman is reported. Histologically, the neoplasm involved the full thickness of the intestinal wall. Tumor cells, mainly displayed epithelioid or polygonal appearance with oval or round nuclei, arranged in strand, nested, and solid pattern with prominent pseudopapillary architecture instead of the familiar histological image with multinucleated osteoclast-like giant cells. They were positive for vimentin, S-100, synaptophysin, CD56 and CD99 protein, but negative for AE1/AE3, EMA, CEA, LCA, Desmin, CK7, CK20, Villin, CgA, CD117, Dog-1, GFAP, Melan-A, HMB-45, CD34, CR, WT1, D2-40. Fluorescence in situ hybridization (FISH) showed the presence of chromosomal translocation involving EWSR. The patients lived through a calm period after a tumor resection and 4 cycles of chemotherapy combining ifosfamide and epirubicin. This case demonstrates that GNET is a rare tumor in gastrointestinal tract, and furthermore, various misleading histological characteristics should been taken into consideration in the diagnosis.
authors: Department of Pathology, The First Affiliated Hospital of Zhengzhou University Zhengzhou, China.
authors: Zhihua
authors: Z
authors: Zhao
authors: Department of Pathology, The First Affiliated Hospital of Zhengzhou University Zhengzhou, China.
authors: Dandan
authors: D
authors: Zhang
authors: Department of Pathology, The First Affiliated Hospital of Zhengzhou University Zhengzhou, China.
authors: Wencai
authors: W
authors: Li
authors: Department of Pathology, The First Affiliated Hospital of Zhengzhou University Zhengzhou, China.
authors: Lan
authors: L
authors: Zhang
authors: Department of Pathology, The First Affiliated Hospital of Zhengzhou University Zhengzhou, China.
authors: Zhen
authors: Z
authors: Li
authors: Department of Pathology, The First Affiliated Hospital of Zhengzhou University Zhengzhou, China.
authors: Jun
authors: J
authors: Zhou
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D006801:Humans; D007078:Ileal Neoplasms / Q000235:genetics / Q000473:pathology*; D017404:In Situ Hybridization, Fluorescence; D017599:Neuroectodermal Tumors / Q000235:genetics / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D034802:RNA-Binding Protein EWS / Q000235:genetics; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor; D015514:Oncogene Proteins, Fusion; D034802:RNA-Binding Protein EWS
keywords: FISH; Malignant gastrointestinal neuroectodermal tumor; clear cell sarcoma; ileum; immunochemistry; pseudopapillary