RECTOSIGMOIDECTOMY WITH TME AFTER TEO, IN A PATIENT WITH A LESION MEETING HIGH-RISK CRITERIA

Case Presentation A 62-year-old female patient presented to an oncological reference service with a colonoscopy showing a 20 mm polypoid lesion, with an eroded surface covered by fibrin and irregular microvascularization in the distal rectum, near the first Houston valve, with histopathological findings of intramucosal adenocarcinoma. Staging exams, including MRI, reported an apparent sessile lesion on the anterior wall of the rectum, 6.5 cm from the anal margin, measuring 1.5 cm in length, with no suspicious lymph nodes in the mesorectum and no apparent invasion of the submucosa. A transanal resection using the TEO platform was initially chosen. The histopathological report showed low-grade invasive adenocarcinoma extending into the submucosa, Haggitt level 4, with a submucosal invasion thickness of 5 mm (about two-thirds of the submucosa), angiolymphatic invasion present, and intermediate tumor budding, classified as pT1, with no microsatellite instability. Due to the presence of high-risk factors in the histopathology, additional surgery was planned, and the patient underwent a rectosigmoidectomy with total mesorectal excision and a protective ileostomy via robotic surgery. The pathology of this procedure showed no residual neoplasia in the colon wall, however 2 out of 30 mesorectal lymph nodes were affected by neoplasia, and the patient was referred for adjuvant oncological treatment.

Discussion The use of platforms for resection of rectal tumors is a valid option for sparing patients with early lesions from more extensive surgeries, with total mesorectal excision, as long as the tumor size and location allow for an R0 resection. This procedure should be preceded by thorough staging with pelvic MRI or endorectal ultrasound to assess the tumor's depth in the rectal wall and to check for lymph node involvement. Histopathological predictive factors for lymph node involvement include submucosal invasion, differentiation grade, lymphovascular and/or perineural invasion, and tumor budding. The risk of lymph node metastasis in T1 tumors is between 6.3% and 10%. Transanal endoscopic resection of rectal tumors can be both diagnostic and curative, depending on the lesion's histopathology.

Conclusion This case highlights the importance of proper analysis of the histopathological study following a TEO resection, as, despite the correct indication for local resection, high-risk factors were present, resulting in undetected lymph node invasion on imaging exams.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025