Submucosal gland tumor spreading in mucosal squamous cell carcinoma: a concern for radiofrequency ablation?

Abstract

Radiofrequency ablation (RFA) has been recently proposed as an efficacious alternative for resection of superficial esophageal squamous cell carcinoma (SCC).1Bergman J. Zhang Y.M. He S. et al.Outcomes from a prospective trial of endoscopic radiofrequency ablation of early squamous cell neoplasia of the esophagus.Gastrointest Endosc. 2011; 74: 1181-1190Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar, 2Abrams A. Ablation of esophageal squamous neoplasia: addressing the bigger picture.Gastrointest Endosc. 2011; 74: 1191-1193Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar We report here the case of an 89-year-old woman with a flat hemicircumferential, mucosal-limited (EUS assessment) lower esophageal SCC who underwent endoscopic submucosal dissection with en bloc complete resection of the lesion, without any complications. Microscopically, it was described as a complete resected pT1m1 SCC with spreading to submucosal glands through the muscularis mucosae (Fig. 1) . To date, after 8 months of follow-up, there has been no evidence of recurrence or metastasis. This case illustrates the advantages of en bloc resection of SCC that allowed precise staging of a pT1m1 SCC with the uncommon description of tumor spreading in the submucosal glands without extension to the chorion, inasmuch as no invasion through the basal margin of the glands could be observed. Submucosal glands, generally located in the lower part of the esophagus,3Shimada H. Nabeya Y. Matsubara H. et al.Prediction of lymph node status in patients with superficial esophageal carcinoma: analysis of 160 surgically resected cancers.Am J Surg. 2006; 191: 250-254Abstract Full Text Full Text PDF PubMed Scopus (119) Google Scholar lie in straight rows that extend outward from the esophageal lumen toward the muscularis mucosae both within the mucosa and the submucosa. The consequences of invasion by SCC of these submucosal glands are an increased risk of R1 resection and local recurrence or lymph node metastasis.3Shimada H. Nabeya Y. Matsubara H. et al.Prediction of lymph node status in patients with superficial esophageal carcinoma: analysis of 160 surgically resected cancers.Am J Surg. 2006; 191: 250-254Abstract Full Text Full Text PDF PubMed Scopus (119) Google Scholar A similar risk has been encountered in Barrett's esophagus after ablative therapies. Buried glands beneath regenerative neosquamous epithelium are often found, to varying degrees, on follow-up4Chennat J. Ross A.S. Konda V.J. et al.Advanced pathology under squamous epithelium on initial EMR specimens in patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma: implications for surveillance and endotherapy management.Gastrointest Endosc. 2009; 70: 417-421Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar and may be a cause of concern because of the difficulty of detecting them under the neosquamous epithelium. The possible extension of the cancer to the submucosal glands below the muscularis mucosae questions the efficacy of ablation techniques such as RFA, which has recently been promoted as an alternative or complementary treatment to endoscopic resection for eradicating early esophageal cancer, including SCC,1Bergman J. Zhang Y.M. He S. et al.Outcomes from a prospective trial of endoscopic radiofrequency ablation of early squamous cell neoplasia of the esophagus.Gastrointest Endosc. 2011; 74: 1181-1190Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar, 2Abrams A. Ablation of esophageal squamous neoplasia: addressing the bigger picture.Gastrointest Endosc. 2011; 74: 1191-1193Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar, 5van Vilsteren F. Pouw R. Seewald S. et al.Stepwise radical endoscopic resection versus radiofrequency ablation for Barrett's oesophagus with high grade dysplasia or early cancer: a multicentre randomised trial.Gut. 2011; 60: 765-773Crossref PubMed Scopus (260) Google Scholar but in which destruction is limited to the mucosa, respecting the muscularis mucosae, and is therefore associated with a low rate of stenosis. If our patient had been treated with RFA, the submucosal glandular component would have been left in situ. Physicians should therefore be aware that mucosal cancer may spread to the submucosal glands, that no conventional pretherapeutic imaging can predict this uncommon glandular extension, and that RFA might not be curative in this setting. Moreover, postablation biopsy appears to be inadequate to allow the exclusion of subsquamous metaplasia/dysplasia because the lamina propria is not present in a large majority of specimens.6Gupta N. Mthur S. Dumot J. et al.Adequacy of esophageal squamous mucosa specimens obtained during endoscopy: are standard biopsies sufficient for postablation surveillance in Barrett's esophagus.Gastrointest Endosc. 2012; 75: 11-18Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar