Local recurrence after rectal endoscopic submucosal dissection: a case of tumor cell implantation

The patient was a 52-year-old male. He had a positive screening fecal occult blood test, and a subsequent colonoscopy at an outside facility revealed a tumor in the lower rectum. He was admitted to our department for further treatment. Colonoscopy at our department showed a 0–IIa lesion, a granular type with lateral spread in the lower rectum (Fig. 1a–d). The procedure for ESD is as follows. A diluted hyaluronic acid solution was injected into the submucosa distal to the tumor. Subsequently, an incision was made into the mucosa distal to the tumor (Fig. 2a). Local injections were repeated as needed while the submucosa was dissected just above the muscular layer toward the proximal side of the tumor (Fig. 2b). Submucosal dissection was performed as the hood compressed the tumor (Fig. 2c). After adequate submucosal dissection was completed, the mucosal incision was extended proximally from the left and right sides to make a circumferential mucosal incision (Fig. 2d). Finally, the remaining submucosal layer was dissected and the tumor was resected en bloc (Fig. 3a). The procedure time required for ESD was 227 min. Grossly, the tumor measured 60×65 mm and the lateral margin was negative (Fig. 3a). The fixed specimen was cut into 33 slices at 2–3 mm intervals (Fig. 3a). Microscopic examination revealed a well-differentiated adenocarcinoma, a negative vertical margin, a negative lateral margin, intramucosal cancer with no vascular invasion, and negative budding (Fig. 3b, c). There was no evidence of histological damage to the muscularis mucosa by any cautery effect or air (Fig. 3b). Curative resection was therefore achieved, defined as satisfying all the following criteria based on the Japanese Society for Cancer of the Colon and Rectum Guidelines 2010 for the Treatment of Colorectal Cancer [2]—negative vertical and lateral margin, depth of submucosal invasion of <1,000 μm, negative vascular invasion, and negative budding. Fifty-three months after ESD, surveillance colonoscopy showed no recurrence on the ESD scar (Fig. 4a). However, 74 months after ESD, surveillance colonoscopy showed an elevated lesion resembling a submucosal tumor with a central depression on the ESD scar (Fig. 4b). A biopsy specimen from a central depression showed group V. We therefore diagnosed the lesion as a local recurrence after ESD and performed a low anterior resection (intersphincteric) with lymph node dissection. Pathology revealed a well-differentiated adenocarcinoma, which was the same as the ESD specimen. The cancer was exposed to the mucosa at the central depression and infiltrated into the muscular layer (Fig. 5). There were no lymph node metastases. A local recurrence was diagnosed 9 months after surgery and the patient underwent an abdominoperineal resection and adjuvant chemotherapy. He is alive with no cancer recurrence.