Abstract
Background: Colorectal cancer (CRC) mostly develops through the traditional “adenoma-carcinoma sequence”, however there is a rare “de novo” carcinogenic pathway in which cancer originates from normal mucosa. Here, we report a case of early CRC caused by “de novo” carcinogenesis with submucosal invasion and conduct a literature review of this special type of CRC.Case presentation: A 66-year-old man underwent a screening colonoscopy that revealed a polyp-like lesion (type 0-IIa+IIc in the Paris classification) approximately 0.5 cm in diameter in the descending colon. The patient underwent endoscopic submucosal dissection (ESD); postoperatively, he was pathologically diagnosed with moderately differentiated adenocarcinoma without an adenomatous component from the “de novo” carcinogenic pathway, accompanied by submucosal invasion to a depth of 600 μm. There was no venous or lymphatic permeation, and the margins were negative. A year later, follow-up examinations did not reveal tumour recurrence.Conclusions: Early “de novo” cancer has a low incidence and a low discovery rate through endoscopy. In this case report, we provide informative details about the presentation of such cancers under endoscopy and further support for the aggressive malignant potential of early “de novo” cancer. The development of advanced CRC can be effectively prevented, and the prognosis of these patients can be improved with active early treatment.
Downregulation of microRNA-100/microRNA-125b is associated with lymph node metastasis in early colorectal cancer with submucosal invasion
