Non‐polypoid colorectal neoplasms are no longer unique to <scp>J</scp>apan, but do not mix up flat and depressed lesions

INTRODUCTION: In contrast to most colorectal carcinomas arising from pedunculated or sessile protruded adenomas, submucosal-invasive (pT1) colorectal carcinoma exhibiting a depressed surface (hereinafter, “depressed colorectal carcinoma,” identified by means of high-definition endoscopy) is considered to be derived from depressed precursors. We hypothesized that depressed colorectal neoplasms have unique clinicopathological features different that are different from those of protruded and flat colorectal neoplasms. METHODS: We classified 27,129 colorectal neoplasms (909 pT1 carcinomas and 26,220 adenomas) resected between 2001 and 2017 into depressed (211 carcinomas and 109 adenomas), flat (304 carcinomas and 11,246 adenomas), and protruded subtypes (394 carcinomas and 14,865 adenomas) and compared their clinicopathological features. As exploratory analyses of pT1 carcinomas, we conducted whole-exome sequencing for 19 depressed and 8 protruded subtypes and RNA sequencing for 8 depressed and 8 protruded subtypes. RESULTS: pT1 carcinomas were more common in depressed lesions (66%) than in protruded (2.6%) and flat lesions (2.6%) (P < 0.001). Compared with nondepressed pT1 carcinomas, depressed pT1 carcinomas were positively correlated with lymphovascular invasion, tumor budding, and massive submucosal invasion and inversely correlated with the presence of an adenoma component (all P < 0.001). Depressed adenomas were more likely to contain high-grade dysplasia than nondepressed adenomas (49% vs 11%, P < 0.001). A KRAS mutation was observed only in one of the 19 depressed pT1 carcinomas. Relative to protruded carcinomas, depressed carcinomas generally exhibited higher expression of genes related to angiogenesis and epithelial-mesenchymal transition. DISCUSSION: Depressed colorectal neoplasms may harbor a unique combination of malignant histopathological phenotypes and molecular features.

show abstract

“…Very tiny depressed lesions are difficult to detect. We focus on the tiny reddish area in normal mucosa and spray indigo carmine ( 29 , 30 ).…”

Section: Discussionmentioning

confidence: 99%

Depressed Colorectal Cancer: A New Paradigm in Early Colorectal Cancer

Kudo

Kouyama

Ogawa

et al. 2020

Clinical and Translational Gastroenterology

View full text Add to dashboard Cite

show abstract

Diminutive intramucosal invasive (Tis) sigmoid colon carcinoma

Fukami

Kudo

Miyachi

et al. 2018

Clin J Gastroenterol

View full text Add to dashboard Cite

A 60-year-old woman underwent colonoscopy, which revealed a red, 5-mm protruded lesion in the sigmoid colon, surrounded by white spots in white-light imaging. Indigo carmine spray indicated endoscopic morphological type Is + IIc. The vessel pattern was diagnosed as JNET-type 2B in magnifying narrow-band imaging, and magnified crystal violet-stained images revealed a VI low-grade pit pattern. We endoscopically diagnosed this lesion as an intramucosal or slightly invasive submucosal carcinoma with low confidence, and performed endoscopic mucosal resection to obtain a total biopsy. Hematoxylin and eosin staining of the resected specimen showed that the surface of the lesion was well-differentiated adenocarcinoma. The muscularis mucosae was identified by desmin immunostaining. There was no lymphovascular infiltration. Structural atypia was notable in the invasive front, indicating well-to-moderately differentiated adenocarcinoma, which invaded the lamina muscularis mucosae. In addition, desmoplastic reaction was recognized to be present. The lesion was, therefore, diagnosed as an intramucosal invasive (Tis) carcinoma, rather than high-grade dysplasia, according to the World Health Organization definition.

show abstract

Non‐polypoid colorectal neoplasms are no longer unique to Japan, but do not mix up flat and depressed lesions

Cited by 2 publications

References 16 publications

Depressed Colorectal Cancer: A New Paradigm in Early Colorectal Cancer

Depressed Colorectal Cancer: A New Paradigm in Early Colorectal Cancer

Diminutive intramucosal invasive (Tis) sigmoid colon carcinoma

Contact Info

Product

Resources

About