PART TWO
Diagnostic Cytology
Fig. 13.47 Yeast forms of
Blastomyces dermatitidis
exhibiting
well-defined cell walls. Typically, internal structure can be discerned, although
this is absent in one of the cells shown. Sputum (Papanicolaou x OI).
In cytologic materials that have been fixed in 95% alcohol
and stained by the Papanicolaou technique,
B. dermatitidis
appears as single or budding spheric cells 8-15 pm in diameter
with thick refractile walls. The thickness of the walls may impart
to these forms a double-contoured appearance. No hyphae are
seen. An important criterion for morphologic confirmation of
blastomyces is the nature of the budding. Single budding is
characteristic. The bud has a tendency to remain in close appo-
sition to the mother cell such that a flattening of the two sur-
faces occurs. Staining is of little help as an aid in identifying
this organism. The wall is highly refractile and may stain cyano-
philically. The cytoplasm stains variably. In some cells, scattered
brownish-red granules are seen embedded in an otherwise non-
staining cytoplasmic mass. In other cells, the entire cytoplasmic
mass may shrink within the cell wall and may show cyanophilic
staining. The unwary may mistake these yeast cells for those of
human origin. The cell wall is mistaken for cytoplasm, and the
cytoplasmic mass is mistaken for a nucleus (Fig. 13.47).169,195,196
The Splendore-Hoeppli phenomenon around these organisms
in cytologic preparations has been reported by Subramony and
colleagues.197
The inflammatory reaction induced by infection with
B. der-
matitidis
may vary from that of the production of classic tuber-
culoid granulomata to the production of microabscesses with a
predominance of neutrophils. The cytologic examination of res-
piratory cellular material from such cases reflects this spectrum
of inflammatory reactivity. One may occasionally also see multi-
nucleated giant cells with the organism within; however, giant
cells without apparent organisms are more frequently seen. The
cellular picture has nothing specific to suggest that infection
with blastomyces has occurred.
The presence in itself of these organisms is diagnostic for infec-
tion. All varieties of respiratory and FNA specimens may reveal
the organisms. The following cases are fairly typical of patients
with pulmonary blastomycosis diagnosed in our laboratory.
A 62-year-old man with diabetes mellitus was transferred
from another hospital. A chest radiograph at that time had
revealed fluffy white infiltrates in both lungs. He had been treated
with large doses of penicillin and corticosteroids. Cytologic
examination of a specimen of sputum revealed the characteristic
budding yeast-like forms of
B. dermatitidis.
He died several days
later. An autopsy revealed systemic blastomycosis. In this case,
the possibility of carcinoma of the lung was considered in the
differential diagnostic interpretation of the radiologic findings.
Had these organisms not been identified, the patient most likely
would have received an exploratory thoracotomy.
In another case, a 9-year-old girl presented with a cavitary
lesion in the left lower lobe. FNA was performed and revealed
the budding yeasts of
B. dermatitidis.
The child lived in a part of
North Carolina where this disease is endemic.
Pulmonary Cryptococcosis
Cryptococcosis is a systemic infectious disease caused by the
yeast-like fungus
Cryptococcus neoformans.
Although infection
most often involves the central nervous system, it may also
involve the lungs, skins, bones, liver, adrenals, kidneys, pros-
tate, endocardium, and pericardium. The causative agent is an
encapsulated organism that reproduces by budding. It has a
worldwide distribution, is found in the soil, and is most fre-
quent in soil contaminated with bird droppings, particularly
those of pigeons. The primary portal of entry into the human
host is through the respiratory tract. The prevalence of human
disease is highest in the United States and Australia. Although
the organism is classified as a primary pathogen, it is more often
encountered as a cause of an opportunistic infection.193
Pulmonary cryptococcosis may encompass a spectrum of
disease that ranges from that with no symptoms to that with a
chronic course and associated with extrapulmonary infection.
Patients with the disease may present with chronic cough, fever,
chest pain, blood-streaked sputum, or mucoid sputum and
weight loss. Radiologic findings may include simple or multiple
nodules that resemble primary lung cancer or metastatic cancer,
consolidation, and pleural effusion.
The budding yeast of
C. neoformans
has been reported in
cytologic preparations of sputum, bronchial material, BALs, and
FNAs.198-203 Like blastomyces, single budding is characteristic of
this yeast; however, in contrast to blastomyces, the single bud of
Cryptococcus
pinches off, leaving a markedly attenuated isthmus
of attachment to the mother yeast cell and thus assuming a tear-
drop shape. The cell is ovoid to spheric, thick walled, and 5-
20 pm in diameter (Figs 13.48 and 13.49). It is usually surroun-
ded by a gelatinous capsule, which may require special stains for
visualization (periodic acid-Schiff, mucicarmine, or Alcian blue).
Occasionally, however, even with Papanicolaou staining alone,
the capsule can be visualized. It may stain faintly cyanophili-
cally, or it may be seen as a nonstaining space between the cell
body and displaced mucus. The visual effect is similar in princi-
ple to an India ink preparation.
As has been reported by Williamson and associates in five
cases, on rare occasions the cryptococcal organism can mani-
fest itself as atypical forms including chains of budding yeasts,
pseudohyphae, and germ tube-like structures. These appearances
could result in misdiagnosing these as
Candida-type
species or
other organisms.204
This finding of pseudohyphae in cryptococcal organisms has
also been reported by Kimura and associates.205
Of additional significance in the correct identification of these
organisms in respiratory specimens is the frequency with which
they may be at the small end of the size spectrum. Because of
this small size, they may be easily overlooked. Additionally, the
cryptococci are much more variable in their internal morphology
than the blastomyces. A rather vague, empty appearance to the
internal structure of the organism may be encountered. A dark
322
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