[Retroperitoneal phlegmon after transanal endoscopic microsurgical excision of rectal adenoma].

We report the case of a 55-year old male patient who underwent transanal endoscopic microsurgery for recurrent benign rectal adenoma. He developed severe postoperative retroperitoneal phlegmon and sepsis and died 28 days after the operation due to untreatable diffuse intraabdominal bleeding caused by persistent thrombocytopenia.