Okuno Takayuki, Kanazawa Takamitsu, Kishi Hirohisa, Anzai Hiroyuki, Yasuda Koji, Ishihara Soichiro
Department of Surgery, Douai Memorial Hospital, 2-1-11 Yokoami, Sumida-ku, Tokyo, 130-8587, Japan.
Department of Pathology, Douai Memorial Hospital, 2-1-11 Yokoami, Sumida-ku, Tokyo, 130-8587, Japan.
Surg Case Rep. 2019 Nov 28;5(1):184. doi: 10.1186/s40792-019-0747-x.
Filiform polyposis is a rare form of inflammatory polyposis, which is occasionally formed in the colon of patients with history of inflammatory bowel disease (IBD). It is characterized by presence of several to hundreds of slender, worm-like polyps in the colon lined by histologically normal colonic mucosa and often coalesce, resulting in a tumor-like mass. Filiform polyposis is most frequently associated with a post-inflammatory reparative process in patients with IBD history, and only cases of filiform polyposis occurring in patients without IBD history have been reported. Filiform polyposis has been considered as a benign inflammatory polyposis without any risk of dysplasia, while the possibility of carcinogenesis of inflammatory polyps is not fully excluded. To date, only three cases of filiform polyposis coexisting with dysplasia have been reported.
A 59-year-old male patient with no past medical history of IBD underwent laparoscopic sigmoidectomy for obstructive filiform polyposis, which was associated with sigmoid colon adenocarcinoma. Based on the histological findings of the resected specimen, invasive sigmoid colon adenocarcinoma was surrounded by filiform polyposis, and adenocarcinoma also scattered uniformly on the surface of filiform polyposis. In immunohistochemistry, abnormal p53 expression was observed in adenocarcinoma, while it was not shown in mucosa on filiform polyposis.
This is the fourth case of filiform polyposis that is closely associated with colon dysplasia or adenocarcinoma based on histological findings. However, immunohistochemical findings did not support the theory that inflammation initiates adenocarcinoma in filiform polyposis like IBD. Hence, further immunohistochemical and genetic analyses are needed to clarify the association between filiform polyposis and carcinogenesis.
丝状息肉病是一种罕见的炎性息肉病，偶尔在有炎症性肠病（IBD）病史的患者结肠中形成。其特征是在结肠中存在数个至数百个细长的、蠕虫状的息肉，这些息肉由组织学上正常的结肠黏膜覆盖，且常融合在一起，形成肿瘤样肿块。丝状息肉病最常与有IBD病史患者的炎症后修复过程相关，仅有在无IBD病史患者中发生丝状息肉病的病例报道。丝状息肉病一直被认为是一种良性炎性息肉病，无任何发育异常风险，而炎性息肉的致癌可能性尚未完全排除。迄今为止，仅报道了3例丝状息肉病合并发育异常的病例。
一名59岁男性患者，无IBD既往病史，因梗阻性丝状息肉病接受腹腔镜乙状结肠切除术，该息肉病与乙状结肠癌相关。根据切除标本的组织学检查结果，浸润性乙状结肠癌被丝状息肉病包围，腺癌也均匀地散在丝状息肉病表面。免疫组织化学检查显示，腺癌中观察到p53异常表达，而丝状息肉病黏膜中未显示。
基于组织学检查结果，这是第四例与结肠发育异常或腺癌密切相关的丝状息肉病病例。然而，免疫组织化学检查结果不支持炎症像IBD那样在丝状息肉病中引发腺癌的理论。因此，需要进一步的免疫组织化学和基因分析来阐明丝状息肉病与致癌作用之间的关联。
