Colon adenoma with an excessively long self-knotted stalk

We performed a colonoscopy on a 64-year-old woman. An excessively elongated polyp was detected in the sigmoid colon. There was a knot at the front end of it, and obvious hyperemia, edema and erosion at the top of this polyp (Fig. 1a). Because of administrative reasons, the polyp was not resected. We biopsied it and the pathological finding indicated inflammatory polyp. Four days later, we performed colonoscopy again and the polyp was found to be necrotic from the knot (Fig. 1b). We used a snare with electrocautery and resected the polyp. Histologic examination showed this was a mixed polyp with low-grade adenoma and a small amount of inflammatory necrotic tissue (Fig. 1c). We believe this is the first case report of an excessively long stalk polyp knotting in the body, and necrosis after biopsy is also extremely rare. We speculated that external forces during biopsy caused ischemia and subsequent necrosis of the mucosa at the knotted site. Although the polyp was successfully removed, a submucosal hematoma occurred during the procedure, and the specimen was fragmented (Fig. 1d).

Figure 1.

There was a knot at the front end of it, and obvious hyperemia, edema and erosion at the top of this polyp (A). The polyp was found to be necrotic from the knot (B). Histologic examination showed this was a mixed polyp with low-grade adenoma and a small amount of inflammatory necrotic tissue (C). A submucosal hematoma occurred during the procedure, and the specimen was fragmented (D).

Knotting has been described in other long and tubular structures, including natural (umbilical cord, ileum)^1,2 and artificial (nasogastric tubes).³ Knotting of colonic polyp has not been reported. We speculate that polyp knotting may be caused by polyp length and rapid intestinal peristalsis, but this needs to be verified by accumulating more cases in the future.

Author's contribution

Yimin Ma cared for the patient. Yimin Ma and Gaomin Cheng wrote the paper. Lijie Cheng was involved doing a literature search. Zhenguo Qiao reviewed the manuscript. Zhenguo Qiao was the guarantor of the overall content of the paper and submitted the paper. All authors read and approved the final version.

Informed consent

The patient provided written informed consent for publication of the data in this study.

Funding

This work was supported by grants from the social development science and technology project of Kunshan (KS18107).

Conflict of interest

All authors have no conflicts of interest to disclose.