[Retroperitoneal abscess due to asymptomatic duodenal perforation by foreign body. A case report].

We present a case of retroperitoneal abscess due to asymptomatic duodenal perforation by foreign body. Patient has been admitted for lumbar pain and subocclusive crisis, with a medical history negative for acute symptomatology. After both clinical and radiologic evaluation, an abscess-like mass was detected in the context of right psoas muscle. Patient underwent surgical operation and a lumbar abscess has been found containing a foreign body (toothpick). There has been a transduodenal migration of the foreign body, without clinical signs of duodenal perforation.