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Barrett's Esophagus Tutorial |
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Problems with Grading of Dysplasia in Barrett’s Esophagus
Two principle problems interfere with the diagnosis and grading
of dysplasia in Barrett’s esophagus: fixation and orientation.
Formalin is not the ideal fixative for nuclear detail, and we rely
heavily on nuclear features for the diagnosis and grading of dysplasia. We
use Hollande’s fixative, which is a modification of Bouin’s solution, for
our biopsy material. We have had excellent results with this fixative, and
if you compare the nuclear detail achieved with Hollande’s solution as
compared to that achieved with formalin, the differences become obvious.
Another important element is proper orientation of the specimen.
Surface epithelial involvement by atypical epithelium is an important
criterion for the diagnosis of dysplasia. Improperly oriented specimens
make it difficult to evaluate the surface epithelium and often result in
the diagnosis of indefinite for dysplasia. Ideally, the endoscopist or an
assistant should orient the biopsy onto a substrate, such as monofilament
mesh, by teasing it out of the biopsy forceps and onto the tip of the
finger. The biopsy can then be carefully flattened out on the fingertip,
mucosal surface down, with the aid of the side of a dissecting needle, and
can subsequently be transferred to the selected substrate with the mucosal
surface up.
The use of the larger 3.4 mm forceps results in larger biopsies than
the standard 2.4 mm biopsy forceps, and they are therefore best for
diagnostic purposes. The larger specimens obtained with these forceps
are easier to orient and have proportionately less crush artifact. The
use of the large forceps is not associated with a higher risk of
complications. In clinical research at the University of Washington,
over 100,000 biopsies have been taken with the larger forceps without
any increase in complications beyond that expected for the smaller
forceps.
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