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Liquid-based
ThinPrep Paps vs. Conventional Pap Smears
In 2001, our lab processed over 8,000 paps by a new liquid-based
technology. Clinicians prepare conventional "pap smears"
by smearing the cervical cell sample directly on a glass slide and
then spray-fixing the cells. With the new liquid-based technology,
the clinician instead places the cervical cell sample directly into
a vial of fixative solution, and then a thin layer of cells is created
in the lab with a Thin PrepÒ processing machine. This allows
for a more uniform layer of cells, better preservation, with less
obscuring by blood and inflammation. The other benefit of this new
technology is that HPV and other ancillary testing can be performed
from the vial of remaining specimen. (Link to Cytyc Corp. ThinPrep
page: http://www.thinprep.com/)
HPV Test
For managing women with ASCUS, reflex HPV DNA testing is now the
preferred approach when liquid-based cytology is used. (Reference
and/or link to Consensus Guidelines and Algorithms.) HPV testing
reveals whether the patient has high-risk or low-risk HPV types.
For HPV testing on ThinPrep samples, the specimen should be less
than 20 days old, and at least 10cc should be remaining in the vial.
For HPV testing on Digene samples, the specimen should be less than
4 weeks old. When an HPV test is requested, the office will receive
a separate report.
ThinPrep® Method
for Collection of GYN (Pap Smear) Specimens
(from "ThinPrep® Pap TestTM Quick Reference Guide",
1997, Cytyc Corporation)
General notes:
1) The specimen should not be taken during menstruation. Douching
prior to the exam and lubricants should be avoided.
2) The cervical transformation zone should be thoroughly sampled
in a patient with a cervix.
3) The pap smear (conventional or ThinPrep) is a screening procedure
to aid in the detection of cervical cancer and its precursors. Both
false positive and false negative results are known to occur.
Broom-like device
protocol:
1) Insert the central bristles of the broom into the endocervical
canal deep enough to allow the shorter bristles to fully contact
the ectocervix. Push gently, and rotate the broom in a clockwise
direction five times.
2) Rinse the broom in the PreservCyt Solution vial by pushing the
broom into the bottom 10 times, forcing the bristles apart. As a
final step, swirl the broom vigorously to further release material.
Discard the collection device.
3) Tighten the cap so that the torque line on the cap passes the
torque line on the vial, label with patient's name, and send in
a plastic bag with completed requisition form.
Endocervical
brush/spatula protocol:
1) Obtain an adequate sampling from the ectocervix using a plastic
spatula.
2) Rinse the spatula in the PreservCyt Solution vial by swirling
the spatula vigorously 10 times. Discard the spatula.
3) Obtain an adequate sampling from the endocervix using an endocervical
brush device. Insert the brush into the cervix until only the bottommost
fibers are exposed. Slowly rotate ¼ or ½ turn in one
direction. DO NOT OVER-ROTATE.
4) Rinse the brush in the PreservCyt Solution by rotating the device
10 times while pushing against the vial wall. Swirl vigorously.
Discard the brush.
5) Tighten the cap so that the torque line on the cap passes the
torque line on the vial, label with patient's name, and send in
a plastic bag with completed requisition form.
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