At the upper left is a remnant of squamous esophageal mucosa that has been undermined by an infiltrating squamous cell carcinoma of the mid-esophagus. Solid nests of neoplastic cells are infiltrating down through the submucosa at the right. Esophageal cancers often spread to surrounding structures, making surgical removal difficult.

Question: What are risk factors for esophageal squamous carcinoma?

AnswerTobacco and alcohol use are risks. Nutritional factors (foods with nitrosamines and tannins, lack of vitamin A and zinc) may play a role in some parts of the world.