A case of undifferentiated-type mucosal gastric cancer with multiple lymph node metastases fulfilling the curative criteria for endoscopic resection according to routine pathological analysis

Abstract

BackgroundEndoscopic resection is accepted as the standard treatment for early mucosal gastric cancer, and its indications have recently been expanded while its long-term outcomes are still unclear. Herein, we present a didactic case of undifferentiated-type mucosal gastric cancer fulfilling the expanded indication and curative criteria for endoscopic submucosal dissection (ESD), having synchronous multiple lymph node metastases.Case presentationA 40-year-old woman was found to have a Helicobacter pylori infection at a standard health check with no abdominal symptoms. She received an upper gastrointestinal endoscopy and found to have an undifferentiated-type mucosal gastric cancer with the size of 15 mm in diameter without ulceration, which fulfilled the expanded indication for ESD. According to patient’s preference, we performed laparoscopy-assisted distal gastrectomy with D1+ lymph node dissection, and routine pathological analysis revealed a predominantly signet ring cell carcinoma limited to the mucosa without ulceration or any vessel involvement; on the other hand, 15 lymph node metastases were detected. Then, we added deep sectioning of the whole tumoral area at a thickness of 20 μm and immunohistochemical analyses. As the result, an isolated lymphatic capillary involvement of the extremely superficial submucosa was identified in a single histological section, and pathological diagnosis was corrected to ly1. She received postoperative adjuvant chemotherapy with an S-1 oral agent and had no recurrence under strict surveillance for 1 year postoperatively.ConclusionsWhen we perform ESD for undifferentiated-type gastric cancer, deep sectioning of the whole tumoral area into thin slices and immunohistochemical staining using D2-40 should be practically considered.

Impact of examining additional deeper sections on the pathological diagnosis of endoscopically resected early gastric cancer

“…Ideally, the pathological diagnosis should be made after evaluating the entire EGC specimens. There were some case reports in which the diagnosis was changed from curative resection to non‐curative resection after lymphatic invasion was detected in additional deeper sections, and we have also had similar experiences. In these cases, the pathological diagnosis re‐evaluated after looking at additional deeper sections was considered to be the correct and final diagnosis, because it was more detailed than that obtained from a routine pathological examination.…”

“…In our experience, we have sometimes had to change the pathological diagnosis after examining additional deeper sections from the specimen. In fact, there were some case reports in which the diagnosis was changed from curative resection to non‐curative resection because lymphatic invasion was detected in deeper sections . Therefore, we considered that the standard method of examining sections from the specimen may be inadequate for the pathological diagnosis of EGC.…”