Abstract
Spigelian hernia occurs on Spigelian aponeurosis between the semilunar line from which the fiber of transversus muscle changes to aponeurosis and the lateral margin of the rectus abdominis muscle. We report a case of Spigelian hernia obtaining a clear image by an abdominal CT scan and the resultant preoperative diagnosis.
A 68-year-old woman was seen at the hospital because of abdominal pain and nausea. A 10cm elastic soft mass with tenderness was palpable in the right lower quadrant, and an abdominal CT scan showed the absence of aponeurosis at the lateral margin of the right rectus abdominis muscle and the intestinal tract projecting out of the abdominal cavity. Having opened the abdomen owing to Spigelian hernia, a 6×8cm hernia sac covered with preperitoneal adipose tissue was present directly below the aponeurosis of external oblique muscle. The content was small intestine. The hernia orifice was 2×3cm in size and located on Spigelian aponeurosis of the lateral margin.
Spigelian hernia occurs in an incidence of 2% or less of all primary abdominal wall hernias, and so far 39 cases have been reported in Japan. In this case, the aponeurosis of the internal oblique muscle and transversus muscle were absent, and the CT demonstrating the layer structure and defective site of the abdominal wall was useful for the diagnosis.
