Pleural, Peritoneal, and Pericardial Effusions
Strongyloidiasis, infection by the nematode
S. stercoralis,
is prev-
alent through the tropical and temperate climates but is most
common in warm, wet regions. In the United States, the para-
site is more prevalent in the South. Healthy individuals tolerate
infection by
S. stercoralis
well, but in immunosuppressed patients,
filariform larvae resident in the intestine may penetrate the intes-
tinal wall and spread to other organs in the body and in doing so
provoke the formation of pleural or peritoneal effusion.
We have seen one example of
S. stercoralis
in a serous fluid.127
The patient, a man from Kentucky who was being treated with
developed abdominal symptoms and was found to have ascites.
The ascitic fluid contained larvae of
S. stercoralis.
The patient
died, and necropsy revealed disseminated strongyloidiasis.
Other examples of the cytologic detection of
S. stercoralis
serous fluids have been reported.128-130 In a case described by
Lintermans, a child died of peritonitis, and
S. stercoralis
found in the peritoneal fluid.129 The diagnosis of infection with
S. stercoralis
is very important because life-saving therapy can be
instituted, in some cases resulting in a cure.
Trichomonads rarely infect serous fluids, and the only fluids in
which they have been reported have been pleural.131-133 In two of
the three reported cases as well as in our own case, invasion of
the pleural cavity by the organism was attributable to an abnor-
mal connection between the respiratory or alimentary tract and
a pleural cavity through a leaking suture line in patients who had
undergone gastrectomy and partial esophagectomy for gastric
adenocarcinoma. In one reported case, the patient developed
empyema as a consequence of aspiration pneumo-
nia, but there was no evidence of any connection between the
respiratory tract and the pleural space.133 In none of the reported
cases of
infections of serous fluid, as in our own
case, was it possible to culture the organism. The significance
of trichomonads in a pleural fluid is unknown. However, it
appears that the organism can be eliminated by treatment with
The organism is easily demonstrated by direct microscopic
examination of fresh unfixed material. In our own case, an
unstained wet film of pleural empyema effusion contained a
scattering of highly mobile trichomonads executing a jerky, roll-
ing movement. We were not able to find the organism in our
Papanicolaou-stained smears.
Giardiasis is infection of the small intestine by the protozoan
Giardia lamblia,
a harmless commensal in most subjects. The
parasite is found worldwide, and higher rates of infection occur
in warmer climates and in crowded, unsanitary environments.
Giardiasis may be epidemic and has achieved some notoriety on
the medical scene by infecting travelers to certain areas.
Giardia lamblia
occurs as trophozoites and cysts. The former
are flat, pear-shaped, binucleated, flagellate organisms, which
are most numerous in the duodenum and upper jejunum. Our
experience of
G. lamblia
in duodenal aspirates has shown that
the organism is quite recognizable in Papanicolaou-stained
material, being about as visible as
Trichomonas vaginalis
in vagi-
nal specimens. However, because of its rarity in peritoneal fluids,
it could easily be overlooked. Examples of
G. lamblia
have been
described in a peritoneal "aspirate," in two peritoneal lavage
specimens, and in "peritoneal fluid."6,134,135 In at least three of
these four patients, the peritoneal specimens were obtained
as part of an investigation to diagnose ruptured intestines
secondary to abdominal trauma. The four specimens contained
trophozoites of
G. lamblia,
and one contained cysts. The signifi-
cance of finding the parasite in peritoneal fluid is that it would
be evidence of perforation of the intestine.
Balantidiasis, infection by the protozoan
Balantidium coli,
worldwide, but infections are more common in tropical and
subtropical regions. In temperate zones, higher rates of infection
develop where there is crowding and poor personal hygiene.
Trophozoites of
B. coli
live in the large intestine, where they
may invade the mucosa, causing ulceration. Perforation of the
bowel wall with accompanying peritonitis is a rare but some-
times fatal complication. Lahiri and associates described a case
of fatal balantidium peritonitis that was diagnosed by cytologic
examination of peritoneal fluid.136
Schistosomiasis (Bilharziasis)
Schistosomiasis is infection caused by flukes (trematodes) of any
species of the genus
. The geographic distribution of
schistosomiasis in humans depends on the distribution of snail
hosts and opportunity for infection for both snail and human.
The basic lesions of schistosomiasis are circumscribed granu-
lomas or eosinophilic and neutrophilic infiltrates around eggs.
The eggs frequently become calcified and surrounded by hyali-
nized scar tissue. Okuyama and co-authors described an ovum
Schistosoma japonicum
in ascitic fluid of an elderly woman who
died with hepatic cirrhosis in which the hepatic scar tissue con-
tained numerous schistosomal ova, and Bedrossian illustrated
an ovum of
Schistosoma mansoni
in a serous effusion, presumably
peritoneal, of a resident of northeastern Brazil.6,137
Amebiasis is invasion of tissue by the protozoan
Entamoeba his-
Infection takes place when trophozoites of
E. histolytica
invade the colonic mucosa, where the infection may remain
localized and minimal for years or may extend to the liver and
other organs. Amebiasis is found worldwide but varies greatly in
severity from patient to patient and from one geographic area
to another.
Complications of colonic amebiasis include peritonitis from
perforation and amebic abscess of the liver. Complications of
liver abscess include perforation and peritonitis and extension
through the diaphragm to the pleural cavity and pericardium.
Therefore, it is entirely possible that a cytologic specimen from
any of the serous cavities could contain
E. histolytica.
We have not seen amebae in any of our specimens of serous
effusion, but they have been described in pericardial fluid of
patients with suppurative amebic pericarditis. The presence of
liver cells in the pericardial fluid of one patient was in keeping
with the amebic pericarditis, being secondary to an amebic liver
abscess that had spread through the diaphragm into the pericar-
dial cavity.138 In most of the patients, the pericardial fluid had
the typical granular gray-pink ("anchovy sauce") appearance.
The type of filariasis usually manifested in serous fluids is ban-
croftian filariasis, an infection by the filarial worm
that causes disease by blocking lymphatic vessels. The
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