A 32-year-old woman was referred to our outpatient department
because of anal bleeding. She had been diagnosed with ulcerative proctitis
about 1 year previously and had experienced intermittent anal bleeding during
treatment at a local clinic. She had no significant medication history and in
particular had not used laxatives or oral iron. The initial colonoscopy
revealed numerous variable-sized areas of black pigmentation in the mucosa of
the terminal ileum ([Fig. 1 a]); however,
the pigment was not detected in the colorectum.
Fig. 1 Endoscopic view of the
terminal ileum showing numerous areas of dark pigmentation during:
a the initial colonoscopy; b the
surveillance colonoscopy 5 year later.
A capsule endoscopy also demonstrated the areas of pigmentation in
the terminal ileal mucosa, although the remainder of the small bowel appeared
normal ([Fig. 2]).
Fig. 2 Capsule endoscopy
showing gray to black pigmented mucosa in the terminal ileum.
Histological examination of biopsy specimens showed coarse black
particles with irregular borders that were freely dispersed or focally
aggregated in the lamina propria and submucosa ([Fig. 3]).
Fig. 3 Histological view of the
terminal ileal mucosa showing brown to black pigment deposition in the lamina
propria.
These areas of pigmentation were negative with Prussian blue and
Fontana–Masson stains.
The patient’s medication history was reviewed after the
evaluation; it was revealed that she had taken two teaspoons of edible charcoal
powder daily for 2 days to relieve abdominal pain before the initial
colonoscopy. Following this test, she took no further charcoal powder, but a
surveillance colonoscopy performed 5 years later showed that the black
pigmented mucosa in the terminal ileum remained unchanged ([Fig. 1 b]).
Pseudomelanosis ilei is rarely reported and in most of the case
reports, iron deposition has been observed in the ileum [1]. Charcoal-induced pseudomelanosis ilei is extremely rare,
with only two cases having been reported in the English literature
[2]
[3]. In our patient, the ileal
pigment was thought to result from charcoal ingestion because she had not taken
laxatives, oral iron, or antihypertensive agents, and the pigments in the
biopsy specimens were negative for iron and melanin stains. The consequences of
charcoal pigmentation are unknown, although it is believed to be a benign
condition, as appears to be the case in our patient. Endoscopists should
consider charcoal ingestion as one of the possible causes of pseudomelanosis
ilei when they observe black pigmentation in the terminal ileum.
Endoscopy_UCTN_Code_CCL_1AC_2AH
