chapter
5
Evaluation of the Sample in Smears
and Liquid-Based Preparations
Marluce Bibbo and Joseph F Nasuti
Contents
In tro d u c tio n
N o n g y n e c o lo g ic C y t o lo g y
C e r v ic o v a g in a l C y t o lo g y
S p e c im e n T y p e
S p e c im e n T y p e
S p e c im e n C r o s s - C o n t a m in a tio n
p a t ie n t I d e n t if ic a t io n
S p e c im e n M is h a n d lin g
C lin ic a l I n f o r m a t io n
C o n c lu d in g R e m a rk s
M ic r o s c o p ic E v a lu a tio n
Introduction
Several factors play a role in the evaluation of the cellular sam-
ple. The method of sample collection and fixation, the labora-
tory procedure to process the sample, and the integration of the
morphologic features observed in the sample with the clinical
information may affect the quality of interpretation/diagnosis
reached.
The ultimate goal in specimen processing is to preserve,
as much as possible, in vitro or in vivo aspects of the sample
obtained. This includes the original size, shape, and texture
of the cytoplasmic and nuclear components present. Among
the desired results of a well-preserved cellular specimen is the
ability to accurately assess quantitative and semiquantitative
criteria including hyperchromasia, nuclear/cytoplasmic ratio,
and chromatin patterns. The recognition of fine nuclear details
such as grooves, notches, inclusions, and pseudo-inclusions
are essential for the definitive diagnosis of certain subtypes of
thyroid, breast, urinary, and soft-tissue tumors with concomi-
tant prognostic implications. Equally important is maximizing
the number of true tissue fragments. In contrast to the screening
nature of the Pap test, where an interpretation of the sample is
followed by a biopsy to establish the final diagnosis, fine-needle
aspiration (FNA) is used to obtain a definitive diagnosis and as
more targeted therapies are developed, expectations on the diag-
nostic performance of cytopathologists will increase.1
Cervicovaginal Cytology
Specimen Type
Two types of specimen are available for cervicovaginal cytology:
smear
for the conventional Pap (CP) and
liquid-based preparation
(LBP), which emerged as an alternative sampling and prepara-
tion method in the 1990s.2 In the United States ThinPrep and
SurePath are the first two LBP approved by the Food and Drug
Administration. In several countries manual methods of LBP
such as DNA Citoliq, Cyto-Screen, PapSpin, and Autocyte
Manual are available. The overall quality of most LBP is surpris-
ingly good because cell preservation is enhanced in contrast to
conventional smears, which may have thick and thin areas or
air-drying artifacts.3,4
Patient Identification
It is important to match the name of the patients on the smears
or LBP vials with the names in the requisition form, to prevent
mix-ups. The use of an automated processing system improves
the accuracy of patient identification and ensures patient chain
of custody with bar-coded labels and etched numbers on the
glass slides.
Clinical Information
Clinical information needs to be integrated with the sample
interpretation. Minimal information required is patient age,
date of last menstrual period, history of previous abnormal Paps,
the latter being more often available in the laboratory compu-
ter system. Age and menstrual status are particularly important
for the interpretation of endometrial cells. A history of previous
malignancies of the female genital tract will alert the laboratory
of the possibility of a recurrent disease or changes secondary to
treatment.
Microscopic Evaluation
In the United States most laboratories follow the 2001 Bethesda
System for reporting cervicovaginal cytology.5 Other countries
utilize national reporting systems. In most laboratory settings
the evaluation of gynecologic specimens is performed by both
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