[Flat adenoma. Endoscopic aspects]

Flat adenomas are small, barely visible, raised lesions, sometimes with a central depression, which may be markers for a familial risk of cancer. Severe dysplasia is found in nearly half the cases. Carcinomas usually considered as occurring de novo may develop from flat adenomas. Detection of flat adenomas is difficult and substantially increases the duration of colonoscopy; therefore it should be reserved for high risk families. The stains and instruments needed to detect flat adenomas are detailed herein, as well as the excision technique.