食道胃接合部に発生したpseudomalignant erosionの4例

Pseudomalignant Erosion at the Esophago-Gastric Junction, Report of Four Cases

要旨　食道胃接合部に発生したpseudomalignant erosionの4例を報告した．全例とも自覚症状に乏しく，検診にて消化管造影あるいは内視鏡検査によって発見された単発性のポリープであり，生検あるいはpolypectomyが施行された．組織学的には，ポリープの表面を覆う重層扁平上皮の一部がびらん性病変を形成し，同部には炎症細胞浸潤を伴う肉芽組織に加えて，大型の組織球様ないし内皮細胞様の，細胞異型および核分裂像に富む細胞が多数認められた．この異型細胞は免疫組織化学的にはvimentinにのみ陽性を示し，他のマーカーはすべて陰性であった．以上より，pseudomalignant erosionと診断した．6か月～6年4か月経過した現在まで再発を認めていない．

　Four cases of pseudomalignant erosion occurred at the esophago-gastric junction (ECJ) were described. All of the patients complained of no symptom at the medical check-up, in which upper gastrointestinal x-ray series or endoscopic examination revealed a small polypoid lesion at ECJ. Histologically, biopsy or polypectomy specimens of all cases were entirely covered by normal stratified squamous epithelium, except for erosive lesions comprising not only granulation tissue with some inflammatory cells but also large cells resembling histiocytes or endothelial cells with severe atypism and mitoses. These atypical cells were immunohistochemically positive only for vimentin, and were negative for other tumor makers useful in identificating tumor cell origin. Thus, these cases were diagnosed as pseudomalignant erosion and have shown no reccurrence of the lesions until now.