D00-D09: In situ neoplasms

D00: Carcinoma in situ of oral cavity, oesophagus and stomach

Carcinoma in situ of the oral cavity, oesophagus, and stomach refers to a group of conditions where abnormal cells are found only in the lining of the oral cavity (mouth), oesophagus (the tube that connects the throat to the stomach), or stomach. These cells have not invaded deeper tissues or spread to other areas of the body and, therefore, are termed 'in situ', meaning 'in its original place'. Causes include chronic irritation from alcohol, tobacco, or refluxed stomach acid, infection with certain types of human papillomavirus (HPV), or chronic infection with a bacterium called Helicobacter pylori. Common symptoms may include a long-lasting sore in the mouth, difficulty swallowing, persistent heartburn, or unexplained weight loss. Although these conditions are initially localized, without treatment they may progress to invasive cancer affecting multiple body systems.