Diagnostic Cytology
Fig. 10.41 Primary invasive malignant melanoma of the cervix.
Conventional cervicovaginal specimen (Papanicolaou x HP). Note the
discohesive nature of the malignant cells.
elevated pHCG levels. The potentially malignant form of GTD
is choriocarcinoma. These tumors follow less than 1 in 20,000
pregnancies,100 most often after an abnormal pregnancy such
as a complete hydatidiform mole, but can follow a normal
pregnancy or abortion. Choriocarcinoma involves a prolifera-
tion of the biphasic trophoblastic tissue consisting of cyto- and
syncytiotrophoblastic cells, without the formation of cho-
rionic villi. These tumors are highly invasive and frequently
metastasize. Nevertheless the prognosis is excellent due to high
response rates to chemotherapy.101
The cytologic features of cyto- and syncytiotrophoblast
have been described in the section "Cytologic Findings during
Gestation." Although the trophoblast associated with GTD
will be abundant and may show more atypia, neither of these
features is sufficient to allow definitive diagnosis with exfoliative
cytology. Other than the rare cases in which exfoliative cytol-
ogy may detect such abnormal trophoblasts, exfoliative cytology
and direct endometrial sampling have no role in the diagnosis
or monitoring of GTD.
Extrauterine Cancer
Carcinoma of the Fallopian Tube
Carcinoma of the fallopian tube is an uncommon malignancy
accounting for < 1% of all gynecologic cancers. Abnormal cells
from a fallopian tube carcinoma can present in cervicovagi-
nal cytology either due to cervical or vaginal metastases or by
direct passage of the cells from the tube lumen into the uterine
cavity and cervical canal. In a review of the literature, Gupta
found that 10% of extrauterine malignancies that presented
with abnormal cervical cytology arose in the fallopian tube.102
A preoperative diagnosis of fallopian tube carcinoma is made
in less 10% of cases103 but 14% of such patients will have an
abnormal Pap test.104 Therefore, cervicovaginal cytology may
provide an opportunity to increase the detection of these rare
carcinomas. Fallopian tube carcinoma should be suspected in
a woman that has malignant glandular cells in her cytology
but endocervical and endometrial workup has failed to reveal
a source.103
The most common malignancy involving the fallopian tube
is a serous adenocarcinoma that arises from the lining of the
tube. In cervicovaginal cytology serous cells are present in small
papillary or acinar arrangements. Individual cells have promi-
nent nucleoli, coarse chromatin, and cytoplasmic vacuoles.102
The number of abnormal cells is usually less than that seen
with endometrial or endocervical primaries. The background is
usually clean and lacking diathesis.103 The absence of a diathe-
sis in conventional cytology preparations may be useful in dis-
tinguishing endometrial from extrauterine adenocarcinoma.76
Psammoma bodies are a common finding in well-differenti-
ated serous carcinoma and they may be found in association
with malignant glandular cells detected with cervicovaginal
cytology. However, psammoma bodies are rare, being found
in less than 0.001% of Pap tests.105 The concentrically lami-
nated calcified bodies must be distinguished from inspissated
mucous, degenerated cell blobs in atrophy, and foreign mate-
rial.105 The finding of psammoma bodies may raise concerns
about associated malignancy; however, the reported rates
vary from 0 to 22% and the majority of cases are associated
with benign conditions such as inflammation, endosalpingi-
osis, and benign neoplasms.105,106 The most reliable indicator
of malignancy is the detection of cytologically abnormal cells
associated with psammoma bodies. However, in the absence
of abnormal cells, psammoma bodies should be reported and
clinically follow-up is warranted.106
Ovarian and Peritoneal Carcinomas
The source of malignant cells in exfoliative cervicovaginal cytol-
ogy specimens in most cases is from the uterus. Less frequently
these cells may have an extrauterine origin. The most common
extrauterine sources are ovarian carcinoma and extragenital car-
cinomas which have involved the pelvic and abdominal peri-
toneum, for example colonic and mammary adenocarcinomas.
These ovarian and peritoneal carcinomas may be detected in
exfoliative cervicovaginal cytology as a result of either mucosal
involvement of the uterus, including cervix, by either the primary
tumor or a metastasis, and/or passage of tumor cells through
patent fallopian tubes. The latter, transtubal route seems to be
the more common method of transit for detected malignant
cells.54 In ovarian carcinoma the presence of ascites increases
the likelihood of malignant cells being detected in cervicovagi-
nal specimens.54,103 Cervicovaginal cytology cannot be used as
a screening method for ovarian carcinoma because malignant
cells are detected in only a minority of cases.54,103
The number of carcinoma cells present in cases of extra-
uterine carcinomas vary widely.54 If tubal passage of carcinoma
cells alone is responsible for the presence of such cells, then
usually they are few in number. Many of the cytologic features
of extrauterine primary carcinomas are shared by endometrial
adenocarcinoma, so these origins generally lack a distinctive
appearance (Fig. 10.42). Cytoplasmic vacuolation, which may
distort the nucleus, is very common, but unlike endometrial car-
cinoma cells in exfoliative cervicovaginal specimens these vac-
uoles rarely contain neutrophils.54 In contrast to both cervical
and endometrial adenocarcinomas in exfoliative cervicovaginal
cytology specimens, there is frequently an absence of any associ-
ated tumor diathesis.
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