Spigelian Hernia Presenting As Abdominal Wall Abscess

Dear Editor, Spigelian hernia can be described as a protrusion of a peritoneal sac, organ, or preperitoneal fat through a congenital or acquired defect in the Spigelian fascia, which is the part transeversus abdominis aponeurosis that lies between the semilunar (Spigelian) line and the lateral edge of the rectus muscle, often above the inferior epigastric vessels, at the level of the arcuate line where the fascia is widest and weakest. Some authors have suggested that perforating vessels can weaken the fascia, permitting the entrance of a lipoma and leading to hernia formation. Because of their small neck size, approximately one third of Spigelian hernias in adults appear incarcerated during surgery. Spigelian hernia is in itself very rare and is difficult to diagnose clinically. It has been estimated that it constitutes 0.12% of abdominal wall hernias. Despite the fact that cases of Spigelian hernia have also been reported in children or even infants, it is a relatively rare hernia that occurs usually in females between 40 and 70 years of age, while the etiologic factors classically associated with this defect are claimed to be obesity, chronic obstructive pulmonary disease, prior surgery, and abdominal trauma. Patients with Spigelian hernia usually complain of pain or lump or both at the site of herniation. The pain is sharp and constant or intermittent, or there is a dragging and uncomfortable feeling. It has been estimated that Spigelian hernias are approximately 2% of the abdominal wall hernias that require emergency operation due to incarceration. When strangulation or incarceration of the herniated contents is present, the pain at the hernia site will be severe and constant. A correct preoperative diagnosis is made in only 53 to 75% of patients, and a significant percentage of incarcerated Spigelian hernias are diagnosed during an emergency laparotomy. Spangen reported that 24.1% of Spigelian hernias reach the surgeon incarcerated and that the hernial sac contents are usually found to be small bowel, colon, or omentum. This is supported by our patient in whom hernia sac content was omentum. This report emphasizes possibility of a hernia while a surgeon is dealing with an abdominal wall abscess and the surgeon has to be totally sure about the appropriate treatment to prevent devastating complications. A 60-year old obese female presented to our hospital with history of constant pain and lump in the right lower abdominal wall for the last three days. She also gave history of fever for the last two days. Her bowel habits were normal and did not have any other complaint. On examination, a soft lump of about 4x4x1.5 cm was found on right lower abdomen at the margin of the right semilunar line with inflamed overlying skin (Figure 1 and 2).