Intestinal metaplasia of the stomach is a common metaplastic lesion associated with chronic gastritis and mucosal atrophy. However, squamous metaplasia is a comparatively rare condition. On endoscopy, squamous metaplasia is usually observed as a whitish mucosal lesion in the lesser curvature of the cardiac region of the stomach. When Lugol's iodine solution is applied, the lesion stains brown in the same way as normal esophageal mucosa. We report a case of 79-year-old man with a whitish flat lesion in the lesser curvature of the cardiac region on surveillance endoscopy after endoscopic treatment of gastric adenoma. The endoscopic biopsy showed stratified squamous epithelial mucosa.
Squamous metaplasia of the stomach is a relatively unusual clinical condition that has been occasionally described. It can occur during healing of inflammatory conditions,
A 79-year-old man had undergone an endoscopic submucosal dissection for a gastric adenoma with low grade dysplasia 3 years ago. The final histological diagnosis was low grade dysplasia, equal to the preresectional diagnosis. Then he underwent surveillance endoscopy annually. There was no abnormal finding on first and second follow-ups. However, at the third visit, a conventional endoscopy revealed a whitish flat lesion in the lesser curvature of cardiac region of the stomach (
Gastric squamous metaplasia is a somewhat rare clinical entity. Normal gastric columnar epithelium generally appears pink and normal esophageal squamous epithelium appears white on endoscopy. Therefore, if the squamous metaplasia was present in the stomach, it would appear as a whitish lesion. In addition, after spraying Lugol's iodine solution, the lesion would be stained brown like normal esophageal mucosa. Actually in a previous report,
Squamous cell metaplasia may affect the lesser curvature of the stomach preferentially, if it does not spread into the entire stomach.
Lugol's iodine staining interacts with carbohydrate containing structures inside the cell and color of the mucosa changes changes into brown color. Lugol's iodine spraying causes dark brown staining of nonkeratinized squamous epithelium, while decrease or absence of dye uptake is seen in conditions, such as esophagitis, squamous cell dysplasia, or carcinoma, which result from depletion of glycogen in squamous cells.
The pathogenesis of squamous metaplasia in the stomach remains obscure.
In summary, if a whitish lesion is observed in the lesser curvature of the cardiac region of the stomach and if it appears a normal esophageal mucosa, application of Lugol's iodine solution is helpful in distinguishing squamous metaplasia from other whitish mucosal lesions such as gastric adenoma or early gastric cancer.
The authors have no financial conflicts of interest.
A surveillance endoscopy after endoscopic treatment of gastric adenoma. An area of whitish lesion is found in the lesser curvature of the cardiac region of the stomach.
Chromoendoscopy using Lugol's iodine solution. The whitish lesion is stained brown with Lugol's iodine solution.
Histopathologic finding. The biopsy from the white area revealed stratified squamous epithelial mucosa (H&E stain, ×100).