An 82-year-old woman presented with a 24-hour history of sharp, mid-abdominal pain radiating to the right lower quadrant. Physical examination revealed right lower quadrant tenderness with localized rebound and guarding. The patient was afebrile. Laboratory values demonstrated a normal white blood cell count and normal blood chemistry.
An 82-year-old woman presented with a 24-hour history of sharp,
mid-abdominal pain radiating to the right lower quadrant. Physical
examination revealed right lower quadrant tenderness with localized
rebound and guarding. The patient was afebrile. Laboratory values
demonstrated a normal white blood cell count and normal blood
Plain abdominal radiographs showed a nonspecific bowel gas
pattern without evidence of abnormal calcification or soft-tissue
mass. A contrast-enhanced CT scan of the abdomen and pelvis was
performed (figure 1), and a 2-cm thick-walled, fluid-filled mass
was identified in the right mid-abdomen adherent to the wall of the
distal ileum, associated with surrounding inflammatory changes. A
radionuclide scan using 99-m Tc-pertechnetate was negative. The
lesion subsequently was removed surgically (figure 2).
Inflamed Meckel's diverticulum
The gross pathologic specimen was a portion of ileum containing
a purulent, inflamed diverticulum on the antimesenteric border with
inflammation of the mesenteric fat. Microscopic examination
demonstrated gastric metaplasia.
Meckel's diverticulum is the most frequent congenital anomaly
involving the intestinal tract. The incidence at autopsy has been
reported to be 0.3 to 3%.1 This is a true diverticulum because it
contains all the layers of the bowel wall and, unlike
pseudodiverticula, arises from the antimesenteric border. The
diverticulum is formed by incomplete obliteration of the ileal end
of the vitilline duct and usually is located within 100 cm of the
ileocecal valve.1 Histologically, ectopic gastric mucosa is present
in about 25% of all Meckel's diverticula, in over 50% of those that
are symptomatic, and in 90% of those presenting with bleeding.2
Most Meckel's diverticula are clinically silent and become
apparent only in patients with complications, which is reported to
occur in 19% of cases.3 Intestinal obstruction is the most common
complication; it may be caused by any of the following:
strangulation of the bowel, intussusception, volvulus,
incarceration of the diverticulum in a Littre's hernia, or tumors
originating in the diverticulum.4 Another complication, bleeding,
usually occurs in children, where it is the most common presenting
sign. Diverticulitis occurs in 13 to 31% of the patients who have
complications.5 This condition may mimic the symptoms of acute
appendicitis. The inflammation usually results from the effect of
peptic acids produced by ectopic gastric mucosa on the surrounding
ileal mucosa.3 Other causes are similar to acute appendicitis, such
as enteroliths obstructing the lumen.
It may be difficult to diagnose a Meckel's diverticulum unless
it becomes inflamed, as in the case presented here. Radionuclide
scanning with technetium pertechnetate detects ectopic gastric
mucosa in Meckel's diverticula in approximately 80 to 90% of
asymptomatic pediatric patients, but in less than 50% of adults.2
Small bowel series rarely provide the diagnosis, and computed
tomography often is not helpful because it is difficult to
differentiate a Meckel's diverticulum from a bowel loop in the
abdomen on CT.6 However, due to the inflammation in this case, the
Meckel's diverticulum was able to be distinguished from other small
bowel loops, and was therefore able to be diagnosed on the CT
In the appropriate clinical setting, an inflamed Meckel's
diverticulum should be considered (along with the far more common
acute appendicitis) in the differential diagnosis of acute right
lower quadrant pain.
1. Gore RM, Levine MS, Laufer I: Textbook of Gastrointestinal
Radiology, pp 1002-1004. Philadelphia, WB Saunders, 1994.
2. Putman CE, Ravin CE: Textbook of Diagnostic Imaging, ed 2, pp
782-783. Philadelphia, WB Saunders, 1994.
3. Rossi P, Gourtsoyiannis N, Bezzi M, et al: Meckel's
diverticulum: imaging diagnosis. AJR 166:567-573, 1996.
4. Mackey WC, Dineen P: A fifty-year experience with Meckel's
diverticulum. Surg Gynecol Obstet 156:56-64, 1983.
5. Yamaguchi M, Takeuchi S, Awazu S: Meckel's diverticulum:
Investigation of 600 patients in Japanese literature. Am J Surg
6. Ikard RW: Diagnosis of Meckel's diverticulum by computerized
tomography. Tenn Med 89(5):164-165, 1996.
7. Nigogosyan M, Dolinskas C: CT demonstration of inflamed
Meckel's diverticulum. J Comput Assist Tomogr 14(1):140-142,
Prepared by Lance J. Becker, MD and Karen Fried, MD, Lenox Hill
New York, NY.