[Appendicitis necessitatis: appendicitis perforating the abdominal wall].

Perforation of the appendix through the anterior abdominal wall is a rare complication of a frequent disorder. We report on a 37-year old patient presenting with purulent secretion from the right lower abdomen. The CT scan of the abdomen revealed a perityphlitic abscess with perforation of the anterior abdominal wall. The patient underwent laparotomy with appendectomy and subsequent revision of the abdominal wall. Appendicocutaneous fistula due to perforation through the abdominal wall is a rarity. In analogy to empyema necessitatis, which would require the pleural empyema to penetrate the thoracic wall, the entity was denoted appendicitis necessitatis.