Table 13.5 Staining Characteristics of Infectious Organisms Commonly
Seen in Cytologic Specimens from the Lung
M ycobacterium avium
N ocardia asteroides
Coccidioides im m itis
H istoplasm a
G eotrichum candidum
C andida albicans
Aspergillus fum ig atus
PAS = periodic acid-Sch iff; Meth.-Ag = methenamine silver.
diagnosis, which will enable the clinicians to begin therapy on
an informed basis, before the definitive diagnosis is provided
by more sophisticated methods. Avoiding a delay in treatment,
albeit currently experimental, may be life-saving to a patient
who is threatened by an overwhelming viral infection.
Cytologic diagnosis can provide this critical information.
Many reports describe changes in cells from the respiratory
tract in association with a number of different viral infections,
including adenovirus,17,172 herpes simplex,173,174 herpes zoster,171
measles,175 cytomegalovirus,176-178 parainfluenza, and respira-
tory syncytial virus.179-182 The cellular changes occurring in these
patients can be divided into three general categories. First is a
cellular alteration observed and named ciliocytophthoria by
Papanicolaou in 1956.183 This is a peculiar degeneration of the
ciliated respiratory epithelium in which a pinching off occurs
between the cilia-bearing cytoplasm and the nucleated cyto-
plasm, resulting in an anucleated mass of cytoplasm-bearing
cilia and a degenerating nucleus with cytoplasm (Fig. 13.44).
A second type of cellular alteration most frequently associ-
ated with viral pneumonia may occur and produce diagnostic
problems in differentiation from cancer. This alteration is a
form of regeneration and atypia of the respiratory epithelium
appearing in sputum and bronchial material as tissue fragments
composed of cells bearing enlarged hyperchromatic nuclei
Fig. 13.44 Ciliocytophthoria. Sputum (Papanicolaou x OI).
Fig. 13.45 Herpes simplex. The cell in the center shows the characteristic
multinucleation, nuclear molding, ground-glass appearance of the nuclei, and
peripheral margination of the chromatin. Sputum (Papanicolaou x OI).
with prominent nucleoli. The tightly cohesive features of the
cells in the tissue fragments and the absence of atypical cells
lying singly help in avoiding the incorrect diagnosis of cancer.
The third type of cellular alteration is much more specific and
may be diagnostic for certain viral infections. Most frequently
observed are the changes seen in association with infection with
herpes simplex virus. The hallmark of cellular alteration pro-
duced by herpes is that of cells with multiple molded nuclei,
which may contain eosinophilic irregular inclusion bodies or
exhibit a peculiar type of nuclear degeneration that appears as
slate gray, homogenized contents (Fig. 13.45). Alveolar lining
cells infected by herpes zoster are indistinguishable from those
infected by herpes simplex.
Cells infected by cytomegalovirus are larger and may show
some multinucleation, but they have fewer nuclei and none of
the molding seen in herpes simplex. Large amphophilic, smooth,
intranuclear inclusions, surrounded by very prominent halos and
marked margination of chromatin on the inner surface of the
nuclear membrane, are present. Within the nucleus, cytomega-
lovirus particles take on a protein envelope and migrate out into
the cytoplasm, where they appear as cytoplasmic inclusions man-
ifested as a textured appearance of the cytoplasm. An example of
a cell infected with cytomegalovirus is shown in Fig. 13.46.