A 63-year-old man was referred to our center for endoscopic submucosal dissection (ESD) of a depressed lesion in the lower gastric body. The lesion had been diagnosed as adenocarcinoma on biopsy during a screening esophagogastroduodenoscopy performed 2 weeks previously. The Helicobacter pylori breath test result was positive.
During the magnifying endoscopy with narrow-band imaging (ME-NBI) before ESD, a 3-cm lesion, 0-IIc by Paris classification, was identified (Fig. 1). The lesion was soft in the inflating and deflating test. It was also negative for the nonextension sign, a phenomenon that refers to a localized increase in thickness and rigidity caused by massive submucosal cancer invasion.1 The demarcation line was well defined, and an irregular mesh pattern vessel was noted (Fig. 2). Therefore, the diagnosis was considered as intramucosal differentiated-type cancer. ESD was performed uneventfully. Final pathologic diagnosis was mixed adenocarcinoma with a solid-type poorly differentiated component identified only in the submucosa, with a depth of 1100 μm, staging the lesion at T1b (Fig. 3). There was no vascular invasion and both the horizontal and vertical margins were clear. Because of a mixed-type poorly differentiated pathology and depth of submucosal invasion, endoscopic resection was deemed noncurative. Mixed adenocarcinoma accounts for about 20.2% of early gastric cancers2, 3, 4 and is associated with poor prognosis and metastases.3,5 Surgical resection was recommended because of concern for potential lymph node metastases.
Figure 1.
Lesion under white-light endoscopy. A reddish soft depressive lesion (yellow dashed line) was found in the posterior wall of the lower gastric body.
Figure 2.
Lesion under narrow-band imaging (NBI). With NBI, irregular microvessels (yellow arrows) and clear boundary were visualized (yellow dashed lines).
Figure 3.
Histopathologic examination of the removed specimen. Immunohistochemical double staining for cytokeratin and desmin demonstrated that the muscularis mucosae (outlined with a red dotted boundary) was intact, and solid-type poorly differentiated components (outlined with a red solid linear border) were identified only in the submucosa (hematoxylin and eosin, original magnification ×100).
ME-NBI is essential to evaluate the suitability of early gastric cancer for ESD. However, the depth of observation with magnifying endoscopy is limited to the superficial mucosa. In our case, the poorly differentiated components were all located in the submucosa, which is impossible to diagnose via magnifying endoscopy. This case highlights the limitations of ME-NBI diagnosis, the importance of pathology evaluation, and the need for pre-ESD discussion with patients regarding the possibility of unexpected noncurative resection because of the presence of deeper undifferentiated components at the invasion front that would not be detected by magnifying endoscopy.
Patient Consent
Written informed consent was obtained from the patient for publication of this case and accompanying images.
Disclosure
All authors disclosed no financial relationships.
References
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