Recurrence after polypectomy for a pedunculated polyp with subtle invasion but no unfavorable histology

A 42-year-old male patient presented with hematochezia. Colonoscopy revealed an approximately 3-cm pedunculated polyp with a long stalk, at 14 cm from the anal verge. The head of the polyp had a multi-lobular appearance but no ulceration. The stalk was thin and smooth ([Fig. 1 a]). The lesion was resected using standard polypectomy techniques and retrieved in its entirety. Histology showed that the cut end of the stalk was completely negative, and one of the four sections demonstrated subtle invasion into the submucosal layer of the head of the polyp ([Fig. 2 a]). Tumor cells in this area resembled a low-grade adenoma ([Fig. 2 b]). No lymphovascular invasion, no areas of poor differentiation, and no tumor budding were present. Additional surgery was not indicated, and the patient accepted this decision.

At follow-up 1 year and 4 months later, the polypectomy site was easily identified due to previous tattooing. The tattooed normal mucosa adjacent to the polypectomy site seemed slightly elevated ([Fig. 1 b]) although this finding was not appreciated at that time. At repeat follow-up 2 years and 8 months after presentation, an apparent tumor with ulceration was detected at the polypectomy site, identified by the previous tattoo ([Fig. 1 c]). Surgical resection was then carried out, and the specimen showed pure mucinous adenocarcinoma, with pathologic T3N1 staging. The original paraffin-embedded specimen was cut further for immunohistochemistry studies. An expert pathologist reviewed the histologic findings. However, the present case did not possess any unfavorable histology [1] [2] [3] [4] [5].

Fig. 1 Endoscopic findings of a large pedunculated polyp. a At presentation with a long thin stalk. b At follow-up, 1 year and 4 months later. c At repeat follow-up, 2 years and 8 months after presentation.

Fig. 2 Histology of the polypectomy specimen (hematoxylin and eosin). a × 1. b × 40.

To the best of our knowledge, this is the first description of a pedunculated polyp that was initially resected by endoscopy but relapsed as an advanced carcinoma despite lacking the usual indicators.

Colonoscopists should be aware of such a rare case of recurrence, which was unpredictable. Tattooing may be universally applicable for polypectomy sites with possible invasive cancers.

Endoscopy_UCTN_Code_CCL_1AD_2AB

References

• 1 Cranley J P, Petras R E, Carey W D et al. When is endoscopic polypectomy adequate therapy for colonic polyps containing invasive carcinoma?.  Gastroenterology. 1986;  91 419-427
• 2 Cooper H S, Deppisch L M, Gourley W K et al. Endoscopically removed malignant colorectal polyps: clinicopathologic correlations.  Gastroenterology. 1995;  108 1657-1665
• 3 Whitlow C, Gathright Jr J B, Hebert S J et al. Long-term survival after treatment of malignant colonic polyps.  Dis Colon Rectum. 1997;  40 929-934
• 4 Netzer P, Forster C, Biral R et al. Risk factor assessment of endoscopically removed malignant colorectal polyps.  Gut. 1998;  43 669-674
• 5 Ueno H, Mochizuki H, Hashiguchi Y et al. Risk factors for an adverse outcome in early invasive colorectal carcinoma.  Gastroenterology. 2004;  127 385-394