Squamous cell carcinoma after radiofrequency ablation for Barrett's dysplasia

Abstract

Barrett's oesophagus (BO) is a usually indolent condition that occasionally requires endoscopic therapy. Radiofrequency ablation (RFA) is an effective endoscopic treatment for high grade dysplasia (HGD) and intramucosal cancer in BO. It has a good efficacy, durability and safety profile although complications can occur. Here we describe a case of RFA in a patient with high grade dysplasia. Although the response to treatment was initially very good with the development of neosquamous epithelium, the patient very rapidly developed a squamous cell cancer of the oesophagus confirmed on radiology, histology and immunohistochemistry. Sanger sequencing confirmed that the original HGD and the squamous cell cancer (SCC) were derived from separate clonal origins. The report highlights the fact that SCC of the oesophagus has been noted after endoscopic ablation for BO previously and suggest that ablation of BO may encourage the clonal expansion of cells carrying carcinogenic mutations once a dominant clonal population has been eradicated.

Keywords: Barrett’s oesophagus; High grade dysplasia; Radiofrequency ablation; Squamous carcinoma oesophagus; Squamous cell cancer.

Figure 1

Endoscopic, genetic and histological figures of the patient before and immediately after radiofrequency ablation for Barrett’s related high grade dysplasia. A: Sanger sequencing from columnar lined oesophagus taken in June 2010 (2) showing a mutation in CDKN2A c.286 G > A (p.V100M) (starred). A control sequence is also shown (1); B: Haematoxylin and eosin stain at × 10 magnification from a biopsy taken in June 2010. This demonstrates high grade dysplasia with nuclear pleiomorphism, increased nuclear: cytoplasmic ratio and disordered nuclei (arrow); C: Endoscopic view of the patient’s columnar-lined oesophagus (April 2009) showing classical salmon pink mucosa between 28cm and 36cm from the incisors; D: Endoscopic view of the patient’s re-epithelialized oesophagus (September 2010) after radiofrequency ablation.

Figure 2

Endoscopic, genetic and histological figures of the patient after radiofrequency ablation. A: Endoscopic view of a 4cm ulcerating mass between 35 to 39 cm; B: Example of positive p63 stain of the biopsies taken from the ulcerating mass (arrow); C: Haematoxylin and eosin stain of biopsies taken from the ulcer crater demonstrating invasive squamous cell cancer (arrow); D: Sanger sequencing of a mutation in TP53 c.817 C>T p. R273C (upper panel, starred) Wild type Sanger sequence of TP53 (lower panel).