Kubota O, Kino I, Kimura T, Harada Y
First Department of Pathology, Hamamatsu University School of Medicine, Japan.
Cancer. 1996 Feb 15;77(4):621-6. doi: 10.1002/(sici)1097-0142(19960215)77:4<621::aid-cncr6>3.0.co;2-j.
Nonpolypoid (depressed or flat) neoplasias are rarely seen in the colon and rectum. We previously reported their histogenesis and characteristics in patients with familial adenomatous polyposis (FAP), but their development in patients without FAP has not been studied systematically.
Three hundred specimens of large intestinal mucosa surgically resected from patients with cancers or other diseases, excluding FAP, were examined with a dissecting microscope. The morphologic types, sizes, locations, and frequencies of detectable colorectal neoplasias, and their histologic features, were analyzed.
A total of 297 adenomas (240 polypoid, 32 flat, and 25 depressed type) were obtained. Nonpolypoid adenomas were most frequently found in the transverse and descending colon. Almost all depressed adenomas (24 of 25; 96%) were less than 3 mm in greatest dimension and almost all flat adenomas (31 of 32; 96.9%) were less than 3.5 mm in greatest dimension. Three minute, nonpolypoid adenocarcinomas (mean size, 2.6 mm; range, 2.4-2.9 mm) were also detected, two of them already invaded the submucosal layer.
Minute nonpolypoid type adenomas may be present in the background mucosa of patients without FAP. This study suggests that even minute nonpolypoid adenocarcinomas have an increased potential for endophytic growth.
非息肉样（凹陷型或扁平型）肿瘤在结肠和直肠中很少见。我们之前报道了它们在家族性腺瘤性息肉病（FAP）患者中的组织发生和特征，但尚未对无FAP患者中此类肿瘤的发生情况进行系统研究。
用解剖显微镜检查了300例因癌症或其他疾病（不包括FAP）而接受手术切除的大肠黏膜标本。分析了可检测到的结直肠肿瘤的形态类型、大小、位置、频率及其组织学特征。
共获得297例腺瘤（240例息肉样、32例扁平型和25例凹陷型）。非息肉样腺瘤最常见于横结肠和降结肠。几乎所有凹陷型腺瘤（25例中的24例；96%）最大直径小于3mm，几乎所有扁平型腺瘤（32例中的31例；96.9%）最大直径小于3.5mm。还检测到3例微小的非息肉样腺癌（平均大小2.6mm；范围2.4 - 2.9mm），其中2例已侵犯黏膜下层。
无FAP患者的背景黏膜中可能存在微小的非息肉样腺瘤。本研究表明，即使是微小的非息肉样腺癌也有增加的内生性生长潜能。
