Sessile serrated adenomas/polyps (SSA/Ps) have a well-established malignant potential.
Because of their subtle appearance, they pose a special diagnostic challenge for the
endoscopist [1]
[2].
Improving SSA/P detection and characterization during routine colonoscopy is crucial
to prevent right colon cancer [3]. Acetic acid is a fatty acid. When sprayed on a mucosal surface, it alters the structure
of the glycoproteins and the nuclear and cytoplasmatic proteins of the cells [4]. This process changes the optical properties of these areas and results in acetowhitening.
Positive acetowhitening could occur in SSA/Ps owing to their high number of goblet
cells with high mucous content (glycoproteins).
We present three cases illustrating the usefulness of acetic acid in the detection
and characterization of subtle right colonic lesions in patients undergoing screening
colonoscopy using a standard definition scope (CF-Q150 L colonoscope; Olympus Medical,
Tokyo, Japan).
In the first patient, the lesion was almost invisible, except for the presence of
vessel amputation. Acetic acid instillation clearly showed a well-defined polyp ([Fig. 1 a, b]). In the two other patients, 0-IIa type subtle lesions with unclear, blurry limits
were identified. Acetowhitening not only allowed better definition of the margins
(and pit pattern), but in one case also revealed that an edematous-looking adjacent
area was also part of the polyp ([Fig. 2 a, b], [Fig. 3]).
Fig. 1 Colonic lesion area (inside white arrows) before and after acetic acid instillation.
a Vessel amputation without visible polyp. b Clear polyp identification after acetowhitening.
Fig. 2 Lesion before and after acetic acid instillation. a Subtle lesion without clear margins. b Clear margin delimitation after acetowhitening.
Fig. 3 Pit pattern identification after acetic acid instillation.
Acetic acid chromoendoscopy is inexpensive and easy to perform. We highly recommend
its use to help evaluate subtle serrated lesions and optimize their management.
Video 1 Usefulness of acetic acid chromoendoscopy in the detection and characterization of
subtle right colonic lesions found during routine screening colonoscopy.
Endoscopy_UCTN_Code_TTT_1AQ_2AB
Endoscopy E-Videos is a free access online section, reporting on interesting cases and new techniques
in gastroenterological endoscopy. All papers include a high
quality video and all contributions are
freely accessible online.
This section has its own submission
website at
https://mc.manuscriptcentral.com/e-videos