Revisit the Benefit of Transanal Local Excision for Two Cases of Large Prolapsing Malignant Rectal Polyps

Abstract

Transanal local excision was traditionally practiced to remove rectal polyps or early rectal tumor. Since 1980, Buess et al. have recommended the use of endoscopy technology for transanal endoscopic microsurgery (TEM). This technique was not popular due to technical issues of difficult positioning, tricky technique especially when it was introduced in the pre-laparoscopy era. With the inception of flexible endoscopy technology, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) came in as alternative options for colorectal polyps. However, both these flexible endoscopy techniques have their disadvantages. The earlier had the issues of fragmented specimens, the latter is technically more challenging with higher risk of perforation/bleeding. Therefore, the traditional transanal excision surgery remained popular and a cost-effective option. Here, we reported 2 cases of large malignant rectal polyps with broad-based pedicle. Both the patients’ polyps are prolapsing and can be everted out from the anal canal. With this specific anatomical criterion, we observed that the surgical treatment can be simplified with conventional transanal local excision with minimal blood loss and quicker and good complete resection rate. Adding that, it abates the cost from the aforementioned newer endoscopic technique.

Introduction

Transanal local excision (TALE) has been a traditional method for removing rectal polyps or early rectal tumors. Since 1980, Buess et al. recommended the use of transanal endoscopic microsurgery (TEM), utilizing endoscopy for better precision. However, TEM was not widely adopted initially due to technical difficulties, especially before the era of laparoscopy [1].

With the advent of flexible endoscopy, techniques like endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) emerged as alternatives for colorectal polyp removal. [2] However, these techniques have limitations, such as fragmented specimens with EMR and a higher risk of perforation or bleeding with ESD. A systematic review comparing TEM and ESD showed that TEM had higher en bloc and complete resection (R0) rates and reduced the need for further abdominal surgery, but both methods remain technically demanding. [3] Consequently, conventional transanal excision still holds value as a cost-effective alternative in some cases.

This report describes two cases of large malignant rectal polyps with a broad-based pedicle, both of which prolapsed and could be everted from the anal canal. These specific anatomical features allowed successful treatment with conventional transanal local excision, resulting in minimal blood loss, faster recovery, and good resection outcomes.

Case 1

A 45-year-old woman presented with a prolapsing anal mass for 3 months, associated with per rectal bleeding and difficulty passing stools. She had a history of prolapsing hemorrhoids and a family history of breast cancer. On examination, a 4 × 5 cm polyp was palpable 5 cm from the anal verge. Colonoscopy confirmed a large rectal polyp (Fig. 1), and MRI showed a pedunculated lesion without lymph node or mesorectal fascia involvement. She underwent transanal excision under general anesthesia (Fig. 2), and histology revealed a moderate-grade adenocarcinoma arising from a villous adenoma, with a 2-mm resection margin. She was placed on a surveillance strategy.

Fig. 1.

Colonoscopy finding for the first case

Fig. 2.

Intraoperative picture of the large anorectal polyp for the first case with its resected specimen

Case 2

A 66-year-old man with a 1-year history of prolapsing anal mass and recent per rectal bleeding was referred for polyp excision before undergoing coronary artery bypass surgery. He had a history of diabetes and coronary artery disease. Clinical examination revealed a large polyp 3.5 cm from the anal verge. Colonoscopy suggested a traditional serrated adenoma (Fig. 3). CT and MRI showed no distant metastasis or lymphadenopathy. Due to scarring from a previous hemorrhoidectomy and proximity to the perianal skin, endoscopic resection was not feasible. Transanal excision was performed, revealing two polyps, one in the anorectal region and another 4 cm from the anal verge. Histology showed traditional serrated adenoma and high-grade dysplasia in the anorectal polyp, with uncertain submucosal invasion. Unfortunately, the patient died from a myocardial infarction three weeks later before further treatment options could be discussed.

Fig. 3.

Colonoscopy finding for the second case

Discussion

While advanced endoscopic techniques like TEM and ESD are valuable, traditional transanal excision remains a viable option, particularly for low-lying or prolapsing polyps. Both cases in this report demonstrate that conventional transanal excision is quicker, less costly, and can achieve comparable oncologic outcomes. The first case had a complete excision with clear margins, while the second case, with a challenging low-lying polyp, showed fragmented excision due to scarring.

Accurate preoperative assessment, including MRI for transmural and nodal staging, is crucial for planning surgery. In both cases, no regional lymph node involvement was identified, allowing for surveillance in the first case. However, due to the uncertain margin in the second case, further management would have been considered if the patient had survived. Ultimately, conventional excision remains a practical choice for patients with favorable anatomical conditions.

Author Contribution

All authors agreed with the content of the final manuscript.

Declarations

Ethics Approval

The authors conformed to the provisions of the Declaration of Helsinki in 1995 (as revised in Brazil in 2013).

Consent for Publication

Written informed consent was obtained from the patient for publication of this case report and accompanying images.

Competing Interests

The authors declare no competing interests.