1992, The British Journal of Radiology, 65, 453-454
Case of the month An underdiagnosed abdominal mass? By *R. D. Edwards, MRCP, FRCR and W. Kincaid, FRCR Department of Radiology, Western Infirmary, Dumbarton Road, Glasgow G11 6NT, UK (Received 24 April 1991 and accepted 4 June 1991)
A 49-year-old woman presented with a 6 h history of severe abdominal pain and a superficial, palpable mass in the right lower abdomen. She was obese and had noted a variable swelling in this area for 4 months. A right inguinal herniorrhaphy had been performed 3 months previously. Views from the initial ultrasound (US) of the anterior abdominal wall and subsequent barium follow-through (FT) are shown (Figs 1 & 2). *Author for correspondence.
Figure 1. Longitudinal US scan of the anterior abdominal wall.
Vol. 65, No. 773
Figure 2. View from barium FT examination.
453
Keywords: Abdomen, Hernia, Spigelian hernia, Ultrasound
Case of the month
may dissect the layers of the transverse and internal oblique muscles and present clinically as a mass lateral to the semilunar line. In less than 5% of cases, the sac penetrates the external oblique muscle and lies subcutaneously, as was seen in this patient. In a review of 744 patients with surgically confirmed Spigelian hernia (Spangen, 1984), the mean age was 50 years (range 6-94 years) with a slight female preponderance (male:female ratio = 1:1.4). The hernial orifice is usually less than 2 cm in diameter but may reach 8 cm. Incarceration is seen in 2 1 % of cases treated surgically (Spangen, 1984). The hernial sac most often contains omental fat, small bowel or colon, but may consist solely of pre-peritoneal fat. Rarely, the sac may contain stomach, gallbladder, appendix, Meckel's diverticulum, ovary, uterine fibroid or testicle. An association with inguinal or femoral hernia is recognized. The commonest symptom is pain, which is typically intermittent and is aggravated by prolonged standing or sustained physical effort. A lump, noticed by the patient in 54% of cases (Weiss et al, 1974), may be impalpable as it is normally covered by the external oblique aponeurosis. Localized tenderness may be the only physical sign and may lead to an unnecessary laparotomy. In one series the correct pre-operative diagnosis was made in only 52% of cases, while the remainder were diagnosed as appendicitis, adhesions, tumours and intestinal obstruction (Weiss et al, 1974). Ultrasound can identify the defect in the aponeurosis (Deitch & Engel, 1980), determine the contents of the hernial sac and distinguish it from other causes of an anterior abdominal wall mass (Fried & Meeker, 1979). Barium studies are of value only if the hernial sac contains bowel. Thin section computed tomography (CT) may demonstrate the hernial orifice (Pyatt et al, 1982). Excision of the sac and repair of the defect is the standard surgical treatment. In this case necrotic omentum was found, but the herniated bowel had Figure 3. Oblique spot film of hernial sac. reduced spontaneously. Awareness of the condition is probably the major factor in the diagnosis of Spigelian hernia. Ultrasound The US shows an oval hypoechoic structure of the abdominal wall is the diagnostic method of choice containing gas lying subcutaneously in the anterior and should be considered in a patient with relatively abdominal wall. The barium FT shows a dilated proxinon-specific lower abdominal symptoms with or without mal small bowel and a herniated loop of bowel in the a mass in the region of the Spigelian line. right lower quadrant. An oblique spot film taken during the barium FT (Fig. 3) shows the neck of the hernial sac (curved arrow) and its relationship to the external References DEITCH, E. A. & ENGEL, J. M., 1980. Spigelian hernia. An oblique muscle (arrowheads). ultrasonic diagnosis. Archives of Surgery, 115, 93. FRIED, A. M. & MEEKER, W. R., 1979. Incarcerated Spigelian
Discussion hernia. Ultrasonic differential diagnosis. American Journal of Roentgenology, 133, 107-110. The patient has a Spigelian hernia (also known as a spontaneous lateral ventral hernia). This uncommon PYATT, R. S., ALONA, B. R., DAYE, S., WENZEL, D. J., WOODS, E. & ALEXIEVA, B., 1982. Case report: Spigelian hernia. hernia consists of a defect in the aponeurosis of the Journal of Computer Assisted Tomography, 6, 643-645. transverse abdominal muscle between the semilunar SPANGEN, L., 1984. Spigelian hernia. Surgical Clinics of North (Spigelian) line and the lateral border of the rectus America, 64, 351-366. muscle. 90% occur between the level of the umbilicus WEISS, Y., LERNAU, O. Z. & NISSAN, S., 1974. Spigelian hernia. and the anterior superior iliac spine. The hernial sac Annals of Surgery, 180, 836-839. 454
The British Journal of Radiology, May 1992
Case of the month An underdiagnosed abdominal mass? By *R. D. Edwards, MRCP, FRCR and W. Kincaid, FRCR Department of Radiology, Western Infirmary, Dumbarton Road, Glasgow G11 6NT, UK (Received 24 April 1991 and accepted 4 June 1991)
A 49-year-old woman presented with a 6 h history of severe abdominal pain and a superficial, palpable mass in the right lower abdomen. She was obese and had noted a variable swelling in this area for 4 months. A right inguinal herniorrhaphy had been performed 3 months previously. Views from the initial ultrasound (US) of the anterior abdominal wall and subsequent barium follow-through (FT) are shown (Figs 1 & 2). *Author for correspondence.
Figure 1. Longitudinal US scan of the anterior abdominal wall.
Vol. 65, No. 773
Figure 2. View from barium FT examination.
453
Keywords: Abdomen, Hernia, Spigelian hernia, Ultrasound
Case of the month
may dissect the layers of the transverse and internal oblique muscles and present clinically as a mass lateral to the semilunar line. In less than 5% of cases, the sac penetrates the external oblique muscle and lies subcutaneously, as was seen in this patient. In a review of 744 patients with surgically confirmed Spigelian hernia (Spangen, 1984), the mean age was 50 years (range 6-94 years) with a slight female preponderance (male:female ratio = 1:1.4). The hernial orifice is usually less than 2 cm in diameter but may reach 8 cm. Incarceration is seen in 2 1 % of cases treated surgically (Spangen, 1984). The hernial sac most often contains omental fat, small bowel or colon, but may consist solely of pre-peritoneal fat. Rarely, the sac may contain stomach, gallbladder, appendix, Meckel's diverticulum, ovary, uterine fibroid or testicle. An association with inguinal or femoral hernia is recognized. The commonest symptom is pain, which is typically intermittent and is aggravated by prolonged standing or sustained physical effort. A lump, noticed by the patient in 54% of cases (Weiss et al, 1974), may be impalpable as it is normally covered by the external oblique aponeurosis. Localized tenderness may be the only physical sign and may lead to an unnecessary laparotomy. In one series the correct pre-operative diagnosis was made in only 52% of cases, while the remainder were diagnosed as appendicitis, adhesions, tumours and intestinal obstruction (Weiss et al, 1974). Ultrasound can identify the defect in the aponeurosis (Deitch & Engel, 1980), determine the contents of the hernial sac and distinguish it from other causes of an anterior abdominal wall mass (Fried & Meeker, 1979). Barium studies are of value only if the hernial sac contains bowel. Thin section computed tomography (CT) may demonstrate the hernial orifice (Pyatt et al, 1982). Excision of the sac and repair of the defect is the standard surgical treatment. In this case necrotic omentum was found, but the herniated bowel had Figure 3. Oblique spot film of hernial sac. reduced spontaneously. Awareness of the condition is probably the major factor in the diagnosis of Spigelian hernia. Ultrasound The US shows an oval hypoechoic structure of the abdominal wall is the diagnostic method of choice containing gas lying subcutaneously in the anterior and should be considered in a patient with relatively abdominal wall. The barium FT shows a dilated proxinon-specific lower abdominal symptoms with or without mal small bowel and a herniated loop of bowel in the a mass in the region of the Spigelian line. right lower quadrant. An oblique spot film taken during the barium FT (Fig. 3) shows the neck of the hernial sac (curved arrow) and its relationship to the external References DEITCH, E. A. & ENGEL, J. M., 1980. Spigelian hernia. An oblique muscle (arrowheads). ultrasonic diagnosis. Archives of Surgery, 115, 93. FRIED, A. M. & MEEKER, W. R., 1979. Incarcerated Spigelian
Discussion hernia. Ultrasonic differential diagnosis. American Journal of Roentgenology, 133, 107-110. The patient has a Spigelian hernia (also known as a spontaneous lateral ventral hernia). This uncommon PYATT, R. S., ALONA, B. R., DAYE, S., WENZEL, D. J., WOODS, E. & ALEXIEVA, B., 1982. Case report: Spigelian hernia. hernia consists of a defect in the aponeurosis of the Journal of Computer Assisted Tomography, 6, 643-645. transverse abdominal muscle between the semilunar SPANGEN, L., 1984. Spigelian hernia. Surgical Clinics of North (Spigelian) line and the lateral border of the rectus America, 64, 351-366. muscle. 90% occur between the level of the umbilicus WEISS, Y., LERNAU, O. Z. & NISSAN, S., 1974. Spigelian hernia. and the anterior superior iliac spine. The hernial sac Annals of Surgery, 180, 836-839. 454
The British Journal of Radiology, May 1992
