Diagnostic Cytology
Immunostaining using cell block material is useful to
help differentiate malignant cells from reactive mesothelial
cells. Antibodies useful in this regard include carcinoembry-
onic antigen (CEA), Leu-M1, and B72.3 as well as Calretinin.
Immunocytochemistry also helps clarify the identity of small
numbers of abnormal cells that might otherwise be missed
in a cellular washing from a patient with clinical evidence of
malignancy.14,20,21 However, care should be taken in interpreta-
tion of results because glandular cells from endometriosis may
show positive immunostaining for epithelial markers such
as CEA.
Overinterpretation can be avoided by performing tests on a
panel of antibodies and correlating the results with the morpho-
logic features seen on tissue or cell block material.14
In peritoneal washings of gastrointestinal and gynecologic
cancers, molecular methods have potential to detect small quan-
tities of residual disease not apparent by morphology alone. In
situ hybridization techniques for detection of CEA or human
telomerase RNA components have potential for detection of
small numbers of cancer cells from body fluids in patients with
abdominal malignancies.21-24
Diagnostic Accuracy
Peritoneal lavage cytology is a specific but a relatively insensi-
tive procedure for detection of peritoneal surface involvement
by malignant cells. To be useful, therefore, the cytologic findings
should be evaluated in conjunction with clinical, serologic, and
laparoscopic findings. The sensitivity of peritoneal cytology for
detection of malignant cells varies from 48 to 88% for patients
undergoing primary laparotomy for ovarian carcinoma,1,25 and
includes intraoperative cytologic evaluation.26
Sensitivity is less for second-look procedures and histologi-
cally confirmed microscopic involvement in patients without
gross peritoneal disease.1,27,28 This relates to reduced tumor
burden or poor distribution of cells due to localization by
adhesions. Separate collection of washing samples from mul-
tiple intra-abdominal sites does not appear to increase sensitiv-
ity either.27 Because brushings and smear specimens are usually
obtained from a limited number of sites in the peritoneal cavity
in patients without celioscopic evidence of tumor, the sensitivity
of the technique is understandably low. Sensitivity of washing
for gastric carcinoma is also low but use of adjunctive molecular
techniques may help.22,23
Sensitivity of peritoneal washing cytology for ovarian tumor
of low malignant potential is high and correlates with surface
ovarian involvement and peritoneal implants.29
A small but significant false-positive rate has been noted for
cytologic washings in ovarian carcinoma,15,27,28,30,31 and several
of the contributing factors have been discussed. Histologic
correlation, preparation of cell block, and or immunostains
may help to reduce this false-positive rate in peritoneal
In some cases it is possible that inadequate histologic sam-
pling may account for what has been called erroneous false-
positive results.15,28 Positive washings are infrequent in patients
with clinical stage I endometrial carcinoma.31 Some of these
results could be attributed to lymphatic spread or fallopian tube
extravasation after endometrial biopsy procedures.32 Spread
from lymphatics during hysterectomy procedures has been sug-
gested as the reason for the presence of tumor cells only on post-
procedure washings.33
Fine-needle aspiration (FNA) cytologic evaluation of primary
ovarian masses was introduced as a valuable diagnostic tech-
nique more than 20 years ago.34,35 Despite some initial skepti-
cism as to its accuracy and efficacy, FNA is rapidly becoming the
primary diagnostic and therapeutic maneuver for the evaluation
of clinically and sonographically nonsuspicious cystic ovarian
masses that persist in women of reproductive age. Other com-
mon indications for aspiration cytology include drainage of
large cysts to permit laparoscopic removal of the cyst wall or
ovary,36 avoidance of surgery in the pregnant patient,37 evalua-
tion of ovarian tumors in patients with previously diagnosed
and treated cancers, particularly when surgical options may be
limited, and evaluation of a radiologically suspicious mass in
patients who refuse or cannot tolerate surgical evaluation. The
approach to complex or solid ovarian masses remains surgical
in most instances.
Hesitation in the acceptance of ovarian cyst FNA centers on
concerns regarding peritoneal seeding from tumor cell spillage,38
reliability of cytologic diagnoses,39,40 and redundancy of the
procedure, as up to 75% of benign cysts will recur,41 ultimately
requiring excision. Careful evaluation of clinical and ultra-
sonographic information should be applied to all cysts prior to
aspiration, to limit or eliminate the risk of aspirating a malig-
nant neoplasm, with the small but real possibility of peritoneal
seeding. However, recent trends toward delayed childbearing
have bolstered efforts to preserve ovarian tissue throughout
the reproductive years. Additionally, some fertility drugs have
been associated with an increased incidence of persistent fol-
licle cysts.42,43 FNA drainage of cysts with cytologic evaluation of
the fluid coupled with sclerotherapy to prevent recurrence may
aid in preservation of fertility.44-46 This trend, combined with
improvements in the technology of high-frequency sonography
and increasing experience in the cytopathologic interpretation
of ovarian cyst fluid, has led to broader acceptance and utiliza-
tion of ovarian FNA.47,48
Sampling Techniques
Ovarian aspiration may be performed transvaginally, transrec-
tally, transabdominally (via direct palpation or radiographically
guided), laparoscopically, or directly at the time of laparotomy.
Transrectal FNA is now used rarely, as a result of concerns regard-
ing infection and the availability of other techniques. The trans-
vaginal approach involves the insertion of a 14- to 22-gauge
needle along a vaginal probe guided via real-time sonography.47
Strict sonographic criteria are used to identify cysts that can be
drained safely in this manner. These criteria include size less
than 10 cm; unilaterality; low echogenicity; absence of ascites;
thin, regular walls in unilocular cysts, or thin, smooth septa in
multinodular cysts; and no hypervascular foci on Doppler ultra-
sound.48, 49 Cysts with low-level echogenicity, consistent with
a hemorrhagic or endometriotic cyst, may also be included in
patients with known or suspected endometriosis.41
Basic Histology
The ovaries are paired, ovoid organs that lie near the pelvic
sidewall and lateral to the uterus. They are draped by a fold of
the peritoneal mesothelium, with which the ovarian surface
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