Lugol Iodine Solution Reveals a Well Camouflaged Esophageal Squamous Cell Carcinoma

Abstract

Introduction: Squamous cell carcinoma of the esophagus can be subtle and difficult to diagnose, especially early-stage esophageal squamous cell carcinoma. We describe a case of esophageal squamous cell carcinoma that was almost imperceptible on high-definition white light endoscopy until highlighted by Lugol iodine solution. Case description: A 62-year-old male smoker with alcohol use disorder and chronic pancreatitis was transferred to our institution for further management of a suspected squamous cell carcinoma (SCC) of the esophagus reportedly seen on upper endoscopy. An initial esophagogastroduodenoscopy (EGD) did not show any lesion despite a careful white-light examination. Decision was made to repeat an EGD with Lugol iodine chromendoscopy. Narrow band imaging was also used on repeat EGD for comparison. Endoscopic application of a dilute lugol iodine solution to the esophageal mucosa clearly delineated a 2 cm lesion at 21 cm from the incisors. Targeted biopsies to the mucosal irregularity were then performed and confirmed the diagnosis of esophageal SCC. The patient was clinically staged as 1a by PET-CT and EUS, completed definitive chemotherapy and radiation, and is doing well 6 months after initial diagnosis. Discussion: Lugol chromoendoscopy is a cheap and well-established method for highlighting glycogenpoor cells of early esophageal squamous cell carcinoma. It is most useful in screening high-risk patients such as those with a history of head and neck squamous cell carcinoma. Chest discomfort or pneumonitis are potential complications of Lugol chromendoscopy. Despite the fact that it is a safe, easy, cheap, and widely available technique in the detection of subtle esophageal squamous lesions, Lugol chromendoscopy is not widely practiced or taught in training programs, and we present this case to raise awareness of this technique.1767_A Figure 1. A subtle lesion is barely apparent on high definition white light endoscopy.1767_B Figure 2. Narrow band imaging (NBI) shows a more distinct border around the lesion.1767_C Figure 3. Chromendoscopy with a dilute lugol iodine solution clearly highlights the lesion.