Peritoneal invagination hernia in the virgin abdomen.

Hernias are a common cause of small bowel obstruction. Many different classifications of hernias exist, all differing by location throughout the abdomen and hernia contents. We present a case report that describes a unique hernia-a peritoneal invagination hernia-which may lead to small bowel obstruction. The peritoneal invagination hernia is a defect in the peritoneum, in this case located on the right anterolateral abdominal wall, allowing small bowel to enter and become incarcerated. In our patient, the peritoneal defect was circular with smooth, rolled borders. The defect contained intact peritoneum overlying intact transversalis fascia. The patient had no prior abdominal surgeries. This hernia differs by location and etiology from preperitoneal interparietal hernias, which are found in the inguinal and femoral regions. This case describes a newly characterized abdominal hernia which is hypothesized to be due to a prior intra-abdominal inflammatory process.