Diagnostic Cytology
Fig. 7.73
Enterobius vermicularis
larva in the smear.
smear (Papanicolaou x LP).
Fig. 7.74
Entamoeba histolytica.
In contrast to the
E ntam oeb a gingivalis
seen in Fig. 7.32, the cytoplasm of
E. histolytica
contains red blood cells and
not leukocytic debris. Vaginopancervical smear (Papanicolaou x HP).
discoloration. Bipolar colorless prominence is typical of the eggs
and is diagnostic. The infection is seen in tropical countries.
Entamoeba histolytica
Entamoeba histolytica
is a protozoan that may infect the lower
genital tract. Clinically, the affected area is ulcerated and fun-
gating and can be misdiagnosed as neoplasm. Intermixed with
necrotic material, numerous trophozoite forms can be seen (Fig.
7.74). These histiocytic-type organisms have biphasic cytoplasm
with vesicular nuclei containing a central karyosome. Ingested
red blood cells are often seen within the cytoplasm. Only rarely
may a cyst form be observed in the vaginal smear (Fig. 7.75). This
most likely represents a contaminant from the alimentary tract.
Entamoeba gingivalis
These protozoa may be seen in vaginopancervical smears in asso-
ciation with
Such a relationship was documented
by de Moraes-Ruehsen and associates.45 These histiocytic-type
organisms have numerous ingested fragments of leukocytic
nuclei and cellular debris in the cytoplasm. They do not con-
tain the intracytoplasmic red blood cells commonly observed in
E. histolytica
Fig. 7.75 Cyst of
Entamoeba histolytica.
Vaginopancervical smear
(Papanicolaou x HP).
The most common nematode causing vascular space infection
Wuchereria bancrofti.
Microfilariae may sometimes be seen in
vaginal smears in endemic areas.126 The microfilariae are gen-
erally 175-260 nm in length. They have a pointed tail with
an elongated terminal nucleus. A 5- to 15-nm caudal space is
present beyond the nucleus terminally.
This nematode infection is caused by
Ascaris lumbricoides
Although alimentary in habitat, the organism may migrate to
various parts of the body and be seen in pulmonary and vaginal
specimens. In vaginal smears, both unfertilized and fertilized
ova may be observed.127
Hymenolepis nana
is a cestode that causes alimentary tract symp-
toms. The eggs may occur in the vaginal smear as a contaminant
from the feces.128 Eggs of the various tapeworms can be distin-
guished by detailed morphologic examination.
Water fleas or mites, but more commonly human body louse
Pediculus humanus
or human pubic louse
Phthirus pubis
may be
seen as contaminants in the vaginal smear.
Detached ciliary tufts (Fig. 7.76) can masquerade as parasites
and have been reported as "ciliated protozoa." The appearance
of DCT is a physiologic occurrence when ciliated tufts are shed
in the vaginal smear.128a
Other organisms including
Schistosoma, Toxoplasma,
Balantidium coli,
Turbatrix aceti
(vinegar eels) have been
observed in vaginal smears.
Acquired Immunodeficiency Syndrome (AIDS)
Most of the parasitic infections, although uncommon in West-
ern populations, are being observed with increased frequency
among patients with AIDS. Single and multiple infections occur
in women who are positive for the human immunodeficiency
virus (HIV) and who have a history of intravenous drug abuse
or heterosexual relationships. An association of HIV-induced
immunosuppression with HPV infections and CIN has more
previous page 128 ComprehensiveCytopathology 1104p 2008 read online next page 130 ComprehensiveCytopathology 1104p 2008 read online Home Toggle text on/off