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Meckel's Diverticulitis Due to an Obstructing Enterolith: Ultrasound and CT Appearances
Clinical Radiology (2001) 00: 1±3 doi:10.1053/crad.2000.0702, available online at http://www.idealibrary.com on
Case Report Meckel's Diverticulitis Due to an Obstructing Enterolith: Ultrasound and CT Appearances A N TO N Y P. H IG GI NS O N *, R I C HA R D I. H A L L{ *Department of Radiology and {Departments of Radiology and Surgery, Derby City General Hospital, Derby, UK
It has not been previously emphasized in the literature that Meckel's diverticulitis in the presence of an obstructing enterolith results in a rounded structure with an air/¯uid level, rather than a ¯uid-®lled tubular structure reported in other cases without enteroliths. We report a case which illustrates the ultrasound and computed tomography (CT) appearances of Meckel's diverticulitis due to an obstructing enterolith.CASE REPORT A 52-year-old man presented with a short history of severe sharp lower abdominal pain. There had been no previous episodes. He had previously had an appendicectomy. On examination he was tender in the left iliac fossa with no guarding. There was a low grade pyrexia. The white blood cell count was 9109/l. An initial diagnosis of ureteric colic was made and an intravenous urogram was performed, which did not demonstrate a renal calculus. An ultrasound examination was requested and demonstrated a 5 cm rounded hypoechoic mass to the right of the umbilicus with a surrounding hyperechoic circular area (Fig. 1). At the time of ultrasound, tenderness was localized to this area. There was an echogenic focus anteriorly within the mass with posterior acoustic shadowing. This was interpreted as air anteriorly within a collection. Proximal small bowel was minimally dilated. Retrospectively, a stone with peripheral calci®cation and a lucent centre was identi®ed on the plain radiograph in a corresponding position (Fig. 2). The stone was not demonstrated at ultrasound. The diagnoses of Meckel's diverticulitis or a collection secondary to colonic diverticulitis were entertained, with enteroliths present. It was also considered that the enteroliths not demonstrated at ultrasound might lie within small bowel lumen and relate to a small bowel stricture, possibly due to Crohn's disease with an associated collection. Abdominal CT con®rmed the presence of an enterolith at the neck of a thin walled outpouching related to small bowel, containing an air/¯uid level, with surrounding mesenteric in¯ammatory change in the right paraumbilical area (Fig. 3). Water was given rather than positive oral contrast medium, to avoid obscuring the enterolith present on the plain radiograph. Multiple diverticulae were demonstrated within the sigmoid colon but not in continuity with this area. A diagnosis of Meckel's diverticulitis was made. At laparotomy there was free pus and an in¯amed Meckel's diverticulum with a necrotic tip containing stones impacted proximal to the neck (Fig. 4). The diverticulum was easily dissected o the mesentery and transected at the base. The patient made an uneventful recovery. Author for correspondence and guarantor: Dr Antony Higginson, Department of Radiology, Leicester Royal In®rmary, Leicester LE1 5WW, U.K. Fax: 44 (0) 116 258 671; E-mail: [email protected] 0009-9260/01/000001+03 $35.00/0
Fig. 1 ± Transverse US of right paraumbilical mass, showing air anteriorly (black arrow) within a rounded ¯uid collection (black arrowheads) and surrounding mesenteric in¯ammation.
DISCUSSION
Meckel's diverticula occur in 2% of the population within 2 feet of the ileocaecal valve on the antimesenteric side and are 2 inches long. Stones form in the absence of ectopic gastric mucosa and are typically faceted, laminated or have peripheral calci®cation with a lucent centre [1]. A plain radiograph of the enteroliths which were all extracted from this patient illustrates these appearances as well as the range of densities of calci®cation present (Fig. 5). Enterolith formation is rare. A previous case of Meckel's diverticulitis has been described at ultrasound. In this case the appearance was that of a non-compressible tubular structure with a blind end, concentric layers and a diameter of 21 mm. The ®ndings were mistaken for appendicitis although no continuity with the caecum had been demonstrated [2]. Similar cases of CT demonstration of Meckel's diverticulitis # 2001 The Royal College of Radiologists
2
CLINICAL RADIOLOGY
Fig. 4 ± Surgical appearances of Meckel's diverticulum.
Fig. 2 ± IVU control ®lm showing a stone with peripheral calci®cation and lucent center, in the right paraumbilical area (white arrowhead).
Fig. 5 ± Plain radiograph of the extracted enteroliths demonstrating the various radiographic appearances.
Fig. 3 ± Enhanced axial CT (10 mm collimation) showing obstructing enterolith (white arrow) in the neck of the diverticulum which contains an air/¯uid level (white arrowhead).
have been described, showing tubular ¯uid ®lled structures with surrounding in¯ammatory change [3±6]. This is the ®rst reported case of the ultrasound demonstration of Meckel's diverticulitis due to obstructing enteroliths within the neck of the diverticulum. The
appearances are of a rounded hypoechoic mass containing an air/¯uid level and surrounding mesenteric in¯ammation. It may be dicult to distinguish air from enteroliths, as both may have an echogenic appearance with posterior acoustic shadowing, although air will rise anteriorly within a collection and enteroliths will lie in a dependent position. In this case the presence of air anteriorly obscured the enteroliths present. The corresponding CT performed shows a rounded mass with an air/¯uid level in common with two previous cases of Meckel's diverticulitis described at CT with obstructing enteroliths [7,8]. The use of positive oral contrast medium may have resulted in failure to demonstrate the obstructing enterolith found at surgery in one of these cases. This would re¯ect the dierences in density of the enteroliths present as illustrated by our case, in which even without positive oral contrast all of the enteroliths present were not demonstrated. In view of the use of ultrasound in the diagnosis of appendicitis and similar clinical presentation of Meckel's
3
CASE REPORT
diverticulitis, it is important to be aware of both possible appearances of an in¯amed Meckel's diverticulum. In the absence of obstruction, a blind ending tubular structure with appearances similar to appendicitis may result, although the structure is likely to have a diameter at the upper limit usually found in appendicitis. In this situation, the position and inability to demonstrate continuity with the caecum should raise the possibility of Meckel's diverticulitis. The ultrasound appearance of a well-de®ned rounded hypoechoic mass containing air and ¯uid in the periumbilical area with mesenteric in¯ammation, should also raise the possibility of Meckel's diverticulitis. Positive oral contrast should not be given before CT to con®rm the diagnosis and dierentiate from either appendicitis or colonic diverticulitis, so that the obstructing enterolith likely to be present is demonstrated.
REFERENCES 1 Pantongrag-Brown L, Levine MS, Buetow PC, Buck JL, Elsayed AM. Meckel's enteroliths: clinical, radiologic, and pathological ®ndings. Am J Roentgenol 1996;167:1447±1450. 2 Poelman JG, Hupscher DN, Ritsema GH. Sonographic manifestation of an in¯amed Meckel's diverticulum: a case report. Eur J Radiol 1991;12:45±46. 3 Hughes JA, Hatrick A, Rankin S. Computed tomography ®ndings in an in¯amed Meckel diverticulum. Br J Radiol 1998;71:882±883. 4 Nagler J, Clarke JL, Albert SA. Meckel's diverticulitis in an elderly man diagnosed by computed tomography. J Clin Gastroenterol 2000;30(1):87±88. 5 Nigogosyan M, Dolinskas C. CT demonstration of in¯amed Meckel diverticulum. J Comp Assist Tomogr 1990;14:140±142. 6 Russ PD, Friefeld GD, Nauck CJ, Wilmouth RJ. Infarcted Meckel diverticulum detected by computer tomography. Am J Roentgenol 1988;150:299±300. 7 Macari M, Panicek DM. CT ®ndings in acute necrotizing Meckel diverticulitis due to obstructing enterolith. J Comp Assist Tomogr 1995;19:808±810. 8 Gayer G, Zissin R, Apter S, Shemesh E, Heldenberg E. Acute diverticulitis of the small bowel: CT ®ndings. Abdom Imag 1999;24: 452±455.
Case Report Meckel's Diverticulitis Due to an Obstructing Enterolith: Ultrasound and CT Appearances A N TO N Y P. H IG GI NS O N *, R I C HA R D I. H A L L{ *Department of Radiology and {Departments of Radiology and Surgery, Derby City General Hospital, Derby, UK
It has not been previously emphasized in the literature that Meckel's diverticulitis in the presence of an obstructing enterolith results in a rounded structure with an air/¯uid level, rather than a ¯uid-®lled tubular structure reported in other cases without enteroliths. We report a case which illustrates the ultrasound and computed tomography (CT) appearances of Meckel's diverticulitis due to an obstructing enterolith.CASE REPORT A 52-year-old man presented with a short history of severe sharp lower abdominal pain. There had been no previous episodes. He had previously had an appendicectomy. On examination he was tender in the left iliac fossa with no guarding. There was a low grade pyrexia. The white blood cell count was 9109/l. An initial diagnosis of ureteric colic was made and an intravenous urogram was performed, which did not demonstrate a renal calculus. An ultrasound examination was requested and demonstrated a 5 cm rounded hypoechoic mass to the right of the umbilicus with a surrounding hyperechoic circular area (Fig. 1). At the time of ultrasound, tenderness was localized to this area. There was an echogenic focus anteriorly within the mass with posterior acoustic shadowing. This was interpreted as air anteriorly within a collection. Proximal small bowel was minimally dilated. Retrospectively, a stone with peripheral calci®cation and a lucent centre was identi®ed on the plain radiograph in a corresponding position (Fig. 2). The stone was not demonstrated at ultrasound. The diagnoses of Meckel's diverticulitis or a collection secondary to colonic diverticulitis were entertained, with enteroliths present. It was also considered that the enteroliths not demonstrated at ultrasound might lie within small bowel lumen and relate to a small bowel stricture, possibly due to Crohn's disease with an associated collection. Abdominal CT con®rmed the presence of an enterolith at the neck of a thin walled outpouching related to small bowel, containing an air/¯uid level, with surrounding mesenteric in¯ammatory change in the right paraumbilical area (Fig. 3). Water was given rather than positive oral contrast medium, to avoid obscuring the enterolith present on the plain radiograph. Multiple diverticulae were demonstrated within the sigmoid colon but not in continuity with this area. A diagnosis of Meckel's diverticulitis was made. At laparotomy there was free pus and an in¯amed Meckel's diverticulum with a necrotic tip containing stones impacted proximal to the neck (Fig. 4). The diverticulum was easily dissected o the mesentery and transected at the base. The patient made an uneventful recovery. Author for correspondence and guarantor: Dr Antony Higginson, Department of Radiology, Leicester Royal In®rmary, Leicester LE1 5WW, U.K. Fax: 44 (0) 116 258 671; E-mail: [email protected] 0009-9260/01/000001+03 $35.00/0
Fig. 1 ± Transverse US of right paraumbilical mass, showing air anteriorly (black arrow) within a rounded ¯uid collection (black arrowheads) and surrounding mesenteric in¯ammation.
DISCUSSION
Meckel's diverticula occur in 2% of the population within 2 feet of the ileocaecal valve on the antimesenteric side and are 2 inches long. Stones form in the absence of ectopic gastric mucosa and are typically faceted, laminated or have peripheral calci®cation with a lucent centre [1]. A plain radiograph of the enteroliths which were all extracted from this patient illustrates these appearances as well as the range of densities of calci®cation present (Fig. 5). Enterolith formation is rare. A previous case of Meckel's diverticulitis has been described at ultrasound. In this case the appearance was that of a non-compressible tubular structure with a blind end, concentric layers and a diameter of 21 mm. The ®ndings were mistaken for appendicitis although no continuity with the caecum had been demonstrated [2]. Similar cases of CT demonstration of Meckel's diverticulitis # 2001 The Royal College of Radiologists
2
CLINICAL RADIOLOGY
Fig. 4 ± Surgical appearances of Meckel's diverticulum.
Fig. 2 ± IVU control ®lm showing a stone with peripheral calci®cation and lucent center, in the right paraumbilical area (white arrowhead).
Fig. 5 ± Plain radiograph of the extracted enteroliths demonstrating the various radiographic appearances.
Fig. 3 ± Enhanced axial CT (10 mm collimation) showing obstructing enterolith (white arrow) in the neck of the diverticulum which contains an air/¯uid level (white arrowhead).
have been described, showing tubular ¯uid ®lled structures with surrounding in¯ammatory change [3±6]. This is the ®rst reported case of the ultrasound demonstration of Meckel's diverticulitis due to obstructing enteroliths within the neck of the diverticulum. The
appearances are of a rounded hypoechoic mass containing an air/¯uid level and surrounding mesenteric in¯ammation. It may be dicult to distinguish air from enteroliths, as both may have an echogenic appearance with posterior acoustic shadowing, although air will rise anteriorly within a collection and enteroliths will lie in a dependent position. In this case the presence of air anteriorly obscured the enteroliths present. The corresponding CT performed shows a rounded mass with an air/¯uid level in common with two previous cases of Meckel's diverticulitis described at CT with obstructing enteroliths [7,8]. The use of positive oral contrast medium may have resulted in failure to demonstrate the obstructing enterolith found at surgery in one of these cases. This would re¯ect the dierences in density of the enteroliths present as illustrated by our case, in which even without positive oral contrast all of the enteroliths present were not demonstrated. In view of the use of ultrasound in the diagnosis of appendicitis and similar clinical presentation of Meckel's
3
CASE REPORT
diverticulitis, it is important to be aware of both possible appearances of an in¯amed Meckel's diverticulum. In the absence of obstruction, a blind ending tubular structure with appearances similar to appendicitis may result, although the structure is likely to have a diameter at the upper limit usually found in appendicitis. In this situation, the position and inability to demonstrate continuity with the caecum should raise the possibility of Meckel's diverticulitis. The ultrasound appearance of a well-de®ned rounded hypoechoic mass containing air and ¯uid in the periumbilical area with mesenteric in¯ammation, should also raise the possibility of Meckel's diverticulitis. Positive oral contrast should not be given before CT to con®rm the diagnosis and dierentiate from either appendicitis or colonic diverticulitis, so that the obstructing enterolith likely to be present is demonstrated.
REFERENCES 1 Pantongrag-Brown L, Levine MS, Buetow PC, Buck JL, Elsayed AM. Meckel's enteroliths: clinical, radiologic, and pathological ®ndings. Am J Roentgenol 1996;167:1447±1450. 2 Poelman JG, Hupscher DN, Ritsema GH. Sonographic manifestation of an in¯amed Meckel's diverticulum: a case report. Eur J Radiol 1991;12:45±46. 3 Hughes JA, Hatrick A, Rankin S. Computed tomography ®ndings in an in¯amed Meckel diverticulum. Br J Radiol 1998;71:882±883. 4 Nagler J, Clarke JL, Albert SA. Meckel's diverticulitis in an elderly man diagnosed by computed tomography. J Clin Gastroenterol 2000;30(1):87±88. 5 Nigogosyan M, Dolinskas C. CT demonstration of in¯amed Meckel diverticulum. J Comp Assist Tomogr 1990;14:140±142. 6 Russ PD, Friefeld GD, Nauck CJ, Wilmouth RJ. Infarcted Meckel diverticulum detected by computer tomography. Am J Roentgenol 1988;150:299±300. 7 Macari M, Panicek DM. CT ®ndings in acute necrotizing Meckel diverticulitis due to obstructing enterolith. J Comp Assist Tomogr 1995;19:808±810. 8 Gayer G, Zissin R, Apter S, Shemesh E, Heldenberg E. Acute diverticulitis of the small bowel: CT ®ndings. Abdom Imag 1999;24: 452±455.