Introduction

Local excision (LE) is increasingly used to treat early rectal cancer (cT1-2N0M0), but its role in pT2 cancer remains controversial due to a reported 20–30% risk of lymph node metastasis (LNM). Since this risk is largely linked to adverse histological features, patients without these risk factors may safely avoid completion total mesorectal excision (cTME). We aimed to refine LNM risk in pT2 rectal cancer following LE to better guide decisions on rectal-preserving treatment strategies.

Aims & Methods

Patients with pT2 rectal cancer who underwent en bloc LE for cT1-2N0M0 lesions were retrospectivelly enrolled from seven international centres (2015-2025). Eligible patients received either cTME or active surveillance with MRI follow-up for at least two years. Exclusion criteria were positive resection margins (<0.1mm), synchronous or recurrent colorectal cancer and (neo)adjuvant therapy. LNM were confirmed through TME histology or considered absent when no suspicious lymph nodes appeared on follow-up MRI. A detailed histological review of LE specimens was conducted by specialised pathologists at each participating centre using a standardised protocol. Assessed risk factors included high-grade differentiation and/or mucinous subtype, lymphovascular invasion (small and/or large vessels), tumour budding grade 2-3 and/or poorly differentiated clusters grade 2-3, and perineural invasion. Primary endpoint was LNM rate in patients without histological risk factors. Secondary endpoints included the association between individual risk factors and LNM, as well as locoregional recurrences during active surveillance.

Results

A total of 103 patients (mean age 66 (SD 10), 56% male) with a median lesion size of 25mm (IQR 15) were included. Endoscopic LE was performed in 31 patients (30%) and surgical LE in 72 (70%). After LE, 76 patients (74%) underwent cTME while 27 (26%) opted for active surveillance. The overall LNM rate was 17.5% (18/103). Among the 36 patients (35%) without histological risk factors, the LNM rate was 5.6% (2/36; OR 0.19, 95% CI 0.04-0.87, p=0.032). Both LNM cases were detected in the cTME group. LNM rates per individual risk factor are presented in Table 1.
In the active surveillance group, no locoregional recurrences occurred in the ten patients without risk factors during a median follow-up of 53 months (IQR 26). Among patients with risk factors, two of 14 patients with one risk factor developed a locoregional recurrence and one of two patients with two risk factors. All recurrences occurred intramurally following prior surgical LE. The only patient with three risk factors had no locoregional recurrence but died from unrelated cause at 24 months.

Table 1. Univariate analyses of histological risk factors for lymph node metastasis

Conclusion

In this group of pT2 rectal cancer patients treated with LE, detailed histological analysis suggests a low LNM risk (5.6%) in patients without histological risk factors. No locoregional recurrences occurred in this low-risk group during active surveillance. As 35% of pT2 rectal cancers lacked histological risk factors, a risk-stratified approach could potentially allow a substantial proportion of patients to avoid cTME. Prospective validation in larger cohorts is needed before clinical implementation.

Introduction

Endoscopic resection techniques, particularly endoscopic submucosal dissection (ESD), are increasingly adapted for lesions located beyond the gastrointestinal tract, including the hypopharynx. Atypical lesions in the pyriform sinus are uncommon and pose significant diagnostic and therapeutic challenges due to their anatomical complexity and limited endoscopic experience. We present a rare case of a flat mucosal lesion in the left pyriform sinus, initially suggestive of low-grade dysplasia (LGD) managed by ESD for excisional biopsy. Our optical diagnosis and resection strategy were based on a previously published case by Di et al., who demonstrated the feasibility of modified ESD in the hypopharyngeal region. (BMC Cancer 17, 712 (2017).

Aims & Methods

A 28-year-old female presented with upper abdominal pain and was referred for diagnostic esophagogastroduodenoscopy (EGD). She was a non-smoker with no relevant oncological family history. Routine examination of the esophagus, stomach, and duodenum was unremarkable. However, careful inspection of the hypopharynx revealed a flat elevated lesion (Paris 0-IIa), approximately 10×10 mm in size, with a demarcated border, located in the left pyriform sinus. Under narrow-band imaging (NBI) with dual focus, intrapapillary capillary loop (IPCL) pattern type IV was observed, raising suspicion for low-grade neoplasia or high-grade neoplasia. The lesion was photo-documented, and the patient was referred for therapeutic resection.
ESD was performed under general anesthesia. En bloc excision was achieved without adverse events; the resection time was 12 minutes.

Results

Histopathologic analysis revealed stratified non-keratinizing squamous epithelium overlying subepithelial lymphoid tissue, consistent with mucosa-associated lymphoid tissue (MALT). Areas of lymphoid follicular hyperplasia with fused follicles were present. The epithelium was non-dysplastic, with regenerative changes and mild intraepithelial lymphocytosis. Immunohistochemistry revealed non-block-type p16 staining, and Ki-67 expression was limited to the basal layer. No morphological or immunohistochemical evidence of high-grade squamous intraepithelial lesion (HSIL) was found.
The patient experienced mild local discomfort for two weeks post-procedure, controlled with ibuprofen. Follow-up endoscopy at one month confirmed complete healing with no recurrence.

Conclusion

This case highlights the growing applicability of advanced endoscopic techniques beyond the gastrointestinal tract and emphasizes the diagnostic limitations of optical assessment in small hypopharyngeal lesions. Despite features suggestive of squamous dysplasia, accurate diagnosis relied on excisional biopsy. ESD proved to be a safe and effective therapeutic option in this anatomically challenging location.

References

Di, L., Fu, KI., Xie, R. et al. A modified endoscopic submucosal dissection for a superficial hypopharyngeal cancer: a case report and technical discussion. BMC Cancer 17, 712 (2017). https://doi.org/10.1186/s12885-017-3685-7