A 32-year-old man presented to the emergency department with complaints of mid-abdominal pain, bloating, decreased appetite, and no bowel movements for 2 days.
Prepared by
Vivek Mishra, MD
and
Myron Kirshenbaum, MD
from the Department of Radiology, Advocate Illinois Masonic
Medical Center, Chicago, IL.
CASE SUMMARY
A 32-year-old man presented to the emergency department with
complaints of mid-abdominal pain, bloating, decreased appetite, and
no bowel movements for 2 days. He had stopped taking his medicine
(Pancrease, McNeil Laboratories, Raritan, NJ) 5 months previously.
Clinical examination revealed hypoactive bowel sounds and
tenderness to deep palpation. Stool was heme-negative. His
laboratory work was within normal limits with a normal white blood
cell count and normal amylase and lipase.
DIAGNOSIS
Meconium ileus equivalent in adults
IMAGING FINDINGS
A radiograph of the abdomen, performed in the emergency
department, revealed dilated small bowel loops suggestive of
obstruction. A few foci of peritoneal calcification were also seen
(Figure 1).
A computed tomography (CT) scan of the abdomen, performed after
oral and intravenous contrast administration, revealed dilated
small bowel loops with intraluminal bubbly fecal material seen in
the distal ileum. Large bowel was unremarkable. The pancreas showed
generalized fatty replacement, which is characteristic of cystic
fibrosis. Peritoneal calcification was also seen (Figures 2, 3, and
4). A diagnosis of meconium ileus equivalent was made.
The Gastrografin (Bracco Diagnostics, Princeton, NJ) enema done
in the radiology department did not show any obstructing lesion,
with contrast refluxing into terminal ileum (Figure 5). The patient
was given Gastrografin enemas every 4 hours for the first day, and
every 12 hours on the second day. Patient was also given Golytely
(Braintree Laboratories Inc., Braintree, MA) by mouth on both days.
His abdominal pain gradually subsided and the patient had 6 to 7
bowel movements on the third day with relief of his symptoms. He
was discharged on a pancreatic enzyme supplement.
DISCUSSION
Meconium ileus equivalent is a complication that is encountered
with increasing frequency due to increased longevity of patients
with cystic fibrosis (mucoviscidosis) as a result of improved
treatment methods. Clinically it represents partial or complete
intestinal obstruction. Some patients may experience acute complete
obstruction, but most suffer from chronic partial obstruction, with
recurring colicky abdominal pain and distension. The condition
occurs only in cystic fibrosis patients who have exocrine
pancreatic insufficiency. It has not been seen in other cystic
fibrosis patients or other patients with exocrine pancreatic
insufficiency. The frequency of these symptoms has been reported to
be about 2.4% to 25%.
1
Pathophysiologically, meconium ileus equivalent is caused by a
combination of exocrine pancreatic insufficiency, increased transit
time, and abnormal intestinal mucus and results from obstruction by
putty-like fecal material in the terminal ileum and cecum.
1-3
Microscopically it represents plugging of mucosal crypts with
mucoid secretion, distension of goblet cells, and the presence of a
thick layer of mucus, admixed with fecal material, adherent to the
mucosal surface.
4
Plain films of the abdomen show a small bowel obstruction. A
nodular pattern in the small bowel, with the nodules being larger
than those seen in quiescent cystic fibrosis, has been reported.
5
On imaging, the CT scan may show features of cystic fibrosis,
including fatty replacement of the pancreas, fatty infiltration of
the liver, and partial or complete bowel obstruction with presence
of bubbly fecal material in the terminal ileum and ascending colon.
No other cause for mechanical obstruction may be evident. Other
features of meconium ileus, such as peritoneal calcification, may
also be seen.
The treatment is primarily nonsurgical. Specific treatment with
N-acetyl cysteine, administered orally and/or as an enema, is
recommended. Alternative treatment with water-soluble contrast
medium, such as Gastrografin, administered orally or as an enema
provides an easily available treatment as well as a means to
perform a diagnostic study to rule out mechanical obstruction. It
has a reported success rate of 81%, with 75% of patients treated as
outpatients.
6,7
This was the method employed in our case. It is important that the
physician be familiar with the disease entity and available
treatment methods. Nonoperative treatment is effective and the
morbidity and mortality associated with surgery can be avoided.
CONCLUSION
Meconium ileus equivalent is an entity that is infrequently
encountered, but will be seen more often with the increasing
longevity of patients with cystic fibrosis. It is important to be
aware of this disease, as nonoperative treatment is effective and
the morbidity and mortality of surgery can be avoided.