Preoperative Iodine Staining May Complicate the Demarcation of Esophageal Carcinoma
The patient was a 53-year-old man with no appreciable disease. His alcohol consumption was low (350 mL beer every day) and he did not have a history of smoking. He underwent esophagogastroduodenoscopy as part of a medical checkup and an iodine-unstained area through Lugol chromoendoscopy was pointed out. The next day, he was referred to our institution for further examination. Conventional endoscopy using a high-resolution upper gastrointestinal endoscope (GIF-H260Z; Olympus Medical System Corp., Tokyo, Japan) showed a reddish rough mucosal area on the right side of the middle thoracic esophagus, occupying one third of the circumference of the esophagus (). The lesion was evaluated as a clearly distinguishable brownish area by narrow band imaging (NBI) endoscopy (). Dilated and irregular intraepithelial papillary capillary loop (IPCL) pattern was observed in the whole lesion through magnifying endoscopy with NBI. Although elongation of the IPCL was observed partially in the lesion, severe destruction of the vessels was not observed. These findings suggested that it was either high grade intraepithelial neoplasia or invasive squamous cell carcinoma limited to the lamina propria. After noninvasive observation, 20 mL of 3% Lugol's solution was applied on the esophageal mucosa. The lesion was identified as a clearly distinguishable iodine-unstained area measuring about 40 mm or less in diameter (). A targeted biopsy from the center of the lesion was performed, and the histopathological assessment was atypical squamous cells suggesting squamous cell carcinoma. Computed tomography showed no lymph node metastasis or distant metastasis. Thus, the tumor was thought to be a candidate for ESD.\nESD was performed 22 days after the previous endoscopy. GIF-H260Z was used for evaluation of the horizontal extent of the tumor and marking, and GIF-Q260J for resection of the tumor, respectively. At the time of treatment, the oral border of the tumor was unclear by conventional endoscopy although we used the same endoscope, GIF-H260Z, as in the previous endoscopy (). The lesion was observed as a brownish area with a vague border and could be barely demarcated by magnifying endoscopy with NBI (). After that, intraoperative iodine staining with 3% Lugol's solution was performed, and it revealed a 25 mm unstained area as well as many other small unstained areas scattered on the oral side (). We put marking dots around the identified tumor border including small unstained areas with a 5 mm margin at 2 to 3 mm interval by Dual knife (Olympus Medical System Corp.) because they seemed to concur with the brownish area identified through magnifying endoscopy with NBI and also with the iodine-unstained area observed in the preoperative endoscopy. The ESD procedure was carried out as described previously ().\nHistopathological assessment revealed proliferation of atypical squamous cells limited to the mucosal epithelium, indicating high-grade intraepithelial neoplasia. The tumor size was 35 mm in diameter. Both lateral and vertical margins were tumor-free, and there was no vessel infiltration. The extent of tumor cells seemed to coincide with the preoperative assessment (). Tumor cells were also found in the basal-parabasal layers of the mucosa where small unstained areas were scattered, although superficial layers showed well-differentiation containing glycogen in cytoplasm.\nThe patient was discharged from the hospital 9 days after treatment without any complications. He was pathologically judged to be completely cured, and follow-up endoscopy has detected neither local recurrence nor metachronous lesion so far.