2011, Number 3
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Rev Invest Clin 2011; 63 (3)
Abnormalities in cervical smears stored in plastic bags: Potential cause of false negatives
Ortega-González P, González-Bravo MS, Jiménez-Muñoz-Ledo G, Macías AE
Language: Spanish
References: 12
Page: 263-267
PDF size: 186.80 Kb.
ABSTRACT
Introduction. Cervical smear is the most economic and efficient
diagnostic tool for the screening of cervical cancer. However,
since plastic bags have been used in Guanajuato to
transport and store smears, we have observed cytological abnormalities
which difficult the diagnosis and lead to false negatives.
Objective. To describe those abnormalities.
Methods. Out of 340 women registered in a primary care
center in Mexico, 68 were selected through systematic random
sampling during 2007. A cervical smear was obtained and
placed on two slides. The first sample was allowed to dry, but
the second one was placed into the plastic bag immediately after
fixation. After 15 days all the smears were stained with the
Papanicolaou technique. A certified pathologist, blinded about
the variable of study, interpreted the samples according to the
Bethesda system, and evaluated the presence of necrosis, edema,
holes, and opportunistic microorganisms.
Results.
Of the 68 smears exposed to a humid storage, 36 (53%) were
inadequate for diagnosis (Fisher’s exact probability ‹ 0.001).
From them, 36 (53%) had holes or lagoons, 34 (50%) had
edema, 31 (46%) had necrosis, and 15 (22%) had fungus. On
the other hand, the 68 dried cervical smears were all adequate
for diagnosis and none had the changes or cytological
abnormalities.
Conclusion. The humid transport and
storage of cervical smears produced abnormalities in the
normal morphology that could lead to false negative results.
The guideline for the handling of cervical smears must stress
the importance of allowing the smears to dry completely after
fixation and before storing them in plastic bags.
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