Brief Reports
Importance of ileoscopy during colonoscopy for the early diagnosis of ileal tuberculosis: report of two cases
Vincent K. S. Leung, MBBS, MRCP, Wai Lun Tang,
MBChB, Chi Hang Cheung, MBBS, FRCS, Moon Sing Lai,
MBBS, MRCP, FRCP
Intubation of the terminal ileum during colonoscopy, although well described, is not routinely performed. Terminal ileoscopy is invaluable in cases of
suspected or established inflammatory bowel disease
or lower GI tract bleeding. In recent years, colonoscopy with colonoscopically obtained biopsy specimens has been shown to be useful for the diagnosis
of colonic tuberculosis (TB).1-5 This is a description of
2 patients with normal-appearing colonic mucosa at
colonoscopy in whom the diagnosis of ileal TB would
not have been established if ileoscopy with biopsies
From the Department of Medicine, Department of Pathology, and
Department of Surgery, Alice Ho Miu Ling Nethersole Hospital,
Hong Kong.
Reprint requests: Dr. Vincent K. S. Leung, Department of Medicine,
Alice Ho Miu Ling Nethersole Hospital, Tai Po, New Territories,
Hong Kong SAR.
Copyright © 2001 by the American Society for Gastrointestinal
Endoscopy
0016-5107/2001/$35.00 + 0
37/54/114954
doi:10.1067/mge.2001.114954
VOLUME 53, NO. 7, 2001
V Leung, W Tang, C Cheung, et al.
had not been performed. Incidentally, the diagnostic
procedures in these 2 cases were performed consecutively during the same colonoscopy session.
CASE REPORTS
Case 1
A 48-year-old Chinese man presented with a 3-month
history of epigastric pain accompanied by anorexia, constipation, and weight loss of approximately 5 kg. He was
previously healthy and had no history of TB. Physical
examination did not reveal any abnormality. A complete
blood count and standard serum chemistries were within
normal limits. An erythrocyte sedimentation rate (ESR)
was 2 mm/h (normal: <15 mm/h). Chest radiograph disclosed clear lung fields. Fecal occult blood tests were
repeatedly negative. He was then referred for EGD and
colonoscopy to rule out GI malignancy.
EGD revealed a moderate degree of fundal gastritis, and
a rapid urease test for Helicobacter pylori was positive. The
entire colon, including the cecum and the ileocecal valve,
appeared unremarkable at colonoscopy. Terminal ileoscopy
revealed three 0.5 cm shallow ulcers with normal-appearing surrounding mucosa (Fig. 1A). Biopsy specimens from
the ulcer edges were sent for histologic examination but not
for culture. Histologic examination of the specimens disclosed well-formed granulomas containing Langhans’ giant
cells (Fig. 1B), and Ziehl-Neelsen stain demonstrated several acid-fast bacilli (Fig. 1C). Antituberculous chemotherapy consisting of isoniazid, rifampicin, pyrazinamide, and
GASTROINTESTINAL ENDOSCOPY
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V Leung, W Tang, C Cheung, et al.
Brief Reports
A
Figure 2. Endoscopic view (Case 2) showing small ulcer with
nodular edges in terminal ileum.
ileoscopy at this time revealed no abnormality. Histologic
examination of biopsy specimens obtained randomly from
the terminal ileum disclosed only normal ileal mucosa.
Case 2
A 64-year-old Chinese man was referred from the surgical clinic for EGD and colonoscopy to screen for GI
malignancy. He presented with a 4-month history of
recurrent epigastric pain associated with increased frequency of bowel movements, anorexia, and weight loss.
There was no significant medical history. Examination
was unremarkable. Blood tests and chest radiograph were
not obtained before the endoscopic examinations.
EGD disclosed a moderate degree of antral gastritis
and a rapid urease test for H pylori was positive.
Colonoscopy was performed and the terminal ileum intubated. One 0.5-cm ulcer was noted in the terminal ileum
(Fig. 2). The remainder of the examination was normal.
Histologic examination of biopsy specimens from the ulcer
confirmed the presence of TB with well-formed granulomas containing Langhans’ giant cells, and acid-fast bacilli were present on Ziehl-Neelsen stain. The biopsy specimens were not sent for bacterial culture. The patient
refused to return for further treatment.
B
DISCUSSION
C
Figure 1. A, Endoscopic view (Case 1) showing small discrete ulcer in terminal ileum. B, Photomicrograph of biopsy
from ulcer (Case 1). A granuloma (arrowhead) consisting of
Langhans’ giant cells (asterisks) and histiocytes, scattered
lymphocytes and plasma cells is present (H&E, orig. mag.
×200). C, Photomicrograph showing intracellular refractile,
beaded acid-fast bacilli within Langhans’ giant cells (ZiehlNeelsen, orig. mag. ×600).
ethambutol was initiated. The patient’s symptoms disappeared shortly afterward.
Six months after starting antituberculous treatment,
the patient remained free of GI symptoms and his body
weight had increased by more than 7 kg. Colonoscopy with
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GASTROINTESTINAL ENDOSCOPY
The incidence of intestinal TB has increased along
with the overall resurgence of TB in recent years.6
The signs and symptoms of intestinal TB are nonspecific and a high index of suspicion is important to
ensure timely diagnosis. Associated active pulmonary
disease is present in only about 20% of cases.6
In a review of 297 patients with intestinal TB, the
most frequent sites of involvement were the distal
ileum and cecum, with over 40% of patients having
disease at these sites.7 Other locations, in order of
frequency, were jejunoileum, colon, anorectum,
stomach, appendix, duodenum, and esophagus. The
predilection of the bacillus for the ileocecum is
attributed to 3 factors: (1) relative physiologic stasis
VOLUME 53, NO. 7, 2001
Brief Reports
within the area, (2) a high rate of absorption with
more complete digestion, and (3) an abundance of
lymphoid tissue.6
The most common presenting complaint of patients
with intestinal TB is chronic abdominal pain, which is
present in about 85% of patients.6-7 Weight loss is
noted in two-thirds of cases, a change in bowel habit
in 20%, and fever in 35% to 50%.6,7 Other symptoms
including malaise, anorexia, nausea, vomiting, melena, and rectal bleeding may also be present.4,5
Colonoscopy with procurement of biopsy specimens is considered the most valuable diagnostic
method for identifying colonic and terminal ileal
TB.1-5 Ulcerations and mucosal nodules are the
most common lesions encountered endoscopically,
being present in over 80% to 90% of cases.3-5 The
ileocecal valve is deformed in about half the cases.4,5
Other endoscopic findings include strictures, polypoid lesions, and fibrous strands.3-5 Histologic examination of biopsy specimens may reveal caseating
granulomas containing Langhans’ giant cells, and
acid-fast bacilli may be seen in appropriately
stained slides. Biopsy specimens should also be cultured for TB but the yield is variable.1-4
The 2 patients described here had mild, nonspecific symptoms, normal-appearing colonic mucosa,
and subtle ileal mucosal abnormalities. The diagnosis of TB was only made when biopsy specimens of
the ileal mucosa revealed granulomas and ZiehlNeelsen stain demonstrated acid-fast bacilli. The
biopsy specimens were not sent for bacterial culture
because the endoscopist did not anticipate the diagnosis of TB at the time of ileoscopy. In the absence of
bacteriologic confirmation, Crohn’s disease is an
alternative diagnosis that has to be considered.
However, the granulomas seen in our 2 cases are
compatible with those associated with TB rather
than Crohn’s disease. The granulomas associated
with TB have histologic features that are distinct
from those of Crohn’s disease. They are frequently
large, they tend to coalesce, often contain Langhans’
giant cells, may caseate, and contain acid-fast bacilli.8 In our geographic region, the most likely
pathogen responsible for mycobacterial infection is
Mycobacterium tuberculosis.
Our 2 cases illustrate the importance of ileal
intubation during colonoscopy for the early diagnosis of intestinal TB. It is our belief that both our
patients were in the early stages of tuberculous
infection because the ileocecal valve and the cecum
were spared. In established infection the distal and
proximal aspects of the ileocecal valve are usually
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V Leung, W Tang, C Cheung, et al.
involved simultaneously.9,10 In fact, it has been suggested that ileal disease alone should prompt consideration of another diagnosis.9
Examination of the terminal ileum is optional
during routine colonoscopy, although some investigators recommend ileal intubation in all cases, circumstances permitting.11-13 The diagnostic yield of
routine ileal intubation is low in asymptomatic
patients undergoing surveillance colonoscopy, but
valuable information may be gained in patients with
suspected inflammatory bowel disease, lower GI
tract bleeding, chronic diarrhea, and unexplained
abdominal pain.13,14 Therefore, it is our belief that
intubation of the terminal ileum should be attempted routinely to allow the endoscopist to develop and
maintain the necessary skill.
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