title: Esophageal extraskeletal Ewing's sarcoma.
abstract: Extraskeletal Ewing's sarcoma is a rare tumor. The most common sites of occurrence are on the trunk, extremities, and retroperitoneum. This type of tumor is well characterized by recurrent chromosomal translocation such as t (11;22) (q24;q12) (EWSR1/FLI1) or t (21;22) (q22;q12) (EWSR1/ERG) and overexpression of MIC2/CD99 on tumor cell membrane. We describe the first reported case of an esophageal extraskeletal Ewing's sarcoma with confirmation from immunohistochemical and molecular diagnoses. A 56-year-old man developed a polypoid tumor located in the lower part of the esophagus. The tumor was composed of small-sized round cells showing prominent fibrillar cytoplasmic processes. Intracytoplasmic glycogen was detected in all the tumor cells. Immunoreactivity for MIC2/CD99 was positive on the membrane of all tumor cells. A reverse transcriptase-polymerase chain reaction followed by sequencing revealed an EWSR1/ERG chimeric transcript, which combined EWSR1 exon 10 with ERG exon 6. The present report added a new entity of esophageal small round cell tumor.
authors.affiliation: Department of Pathology, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Chihaya
authors.initials: C
authors.lastname: Maesawa
authors.forename: Sin
authors.initials: S
authors.lastname: Iijima
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Sato
authors.forename: Noda
authors.initials: N
authors.lastname: Yoshinori
authors.forename: Michihiro
authors.initials: M
authors.lastname: Suzuki
authors.forename: Mitsu
authors.initials: M
authors.lastname: Tarusawa
authors.forename: Kaoru
authors.initials: K
authors.lastname: Ishida
authors.forename: Gen
authors.initials: G
authors.lastname: Tamura
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Saito
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Masuda
mesh_terms: D000071443:12E7 Antigen; D015703:Antigens, CD / Q000032:analysis; D001859:Bone Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D015815:Cell Adhesion Molecules / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis; D004938:Esophageal Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000032:analysis; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D014157:Transcription Factors / Q000032:analysis; D014178:Translocation, Genetic
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D004273:DNA, Neoplasm; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors; D006003:Glycogen