Malignant adenoma
*Malignant adenoma* is a precancerous lesion of the colon (sphincter-adenoma of the colon) and the submucosal layer of the stomach. Diagnosed in approximately 30% of cases in patients over 50 years of age. In most cases, the adenoma is malignant, it transforms into a cancerous tumor and is asymptomatic, which leads to untimely contact with specialists and irretrievable loss of time and resources.