7
Microbiology, inflammation, and Viral infections
Fig. 7.54 Human papillomavirus (HPV) infection.
This photomicrograph
reveals the dyskeratosis that frequently accompanies the viral infection. Some
of the cells are elongated, fiber-shaped, and bizarre. These keratinized cells,
if not carefully examined, can be mistaken for evidence of invasive cancer.
Vaginopancervical smear (Papanicolaou stain x MP).
1
5
4
6
7
8
Fig. 7.55 Human papillomavirus (HPV) infection.
This infection appears
to involve the ectocervix and the transformation zone simultaneously. Both
mature squamous cells and immature metaplastic-type cells are observed.
Some of the cells show small tissue fragment formation. Multinucleation and
keratinization are also observed. Vaginopancervical smear (Papanicolaou
stain; X172).
features, especially changes in tinctorial character, occur com-
monly in HPV-infected cells. Abnormal shape is another feature
affecting the squamous epithelial cells. Frayed edges (Fig.
7.54), fiber, and tadpole formations are some of the features
observed in HPV-infected squamous cells. Nuclear changes
must be evaluated in these cases for proper interpretation of
cytomorphology.
Parakeratosis (Fig. 7.55) is another feature that sometimes is
seen in association with HPV infections. This finding is impor-
tant in cases that may not have an inflammatory background.
The parakeratotic cells can reveal abnormal keratinization or
dyskeratosis. Hyperkeratosis may be seen as anucleated squa-
mes. This per se is not considered suggestive of HPV infection,
and a better cellular sample should be examined in such cases.
In cases in which the HPV infection may dominate the
transformation zone or involve the endocervical canal, the
infected cells as observed in vaginopancervical smears appear
Fig. 7.56
A diagrammatic representation of cellular changes in the cervix
following
human papillomavirus (HPV) infection
(see text).
(1) Normal squamous cells. (2) Koilocytes. (3) Plaques of HPV-infected cells.
(4) Parakeratotic cells. (5) Dyskaryosis with atypical forms. (6) Hyperkeratosis
with anucleate squames. (7) Metaplastic-type HPV-infected cells. These
cyanophilic cells have eccentric nuclei and peripheral cytoplasmic
condensation. (8) HPV-infected cells from the transformation zone. These
appear undifferentiated. (9) HPV-infected cells from the transformation zone.
These cells are of unclassified type.
cyanophilic and may not be the keratinized squamous type.
Atypical repair-type cells (discussed elsewhere) may dominate
the smear. Very commonly, these cases have immature, meta-
plastic-type cells infected with HPV in the smear (Figs. 7.56,
7.57). They appear as single and basophilic with dense cyto-
plasm and round or oval shapes. They may be as small as para-
basal or appear as big as intermediate cells. Some anisocytosis
is common in these cells. The cytoplasm may show peripheral
condensation similar to that seen in typical koilocytes. The
nuclei may be eccentrically located, reveal size variation, and
show features of increased activity such as enlargement, chro-
matin granularity, and bi- or multinucleation. The nucleoli
are inconspicuous. When the infection is nested in the trans-
formation zone, parakeratotic and metaplastic-type cells may
predominate. Small tissue fragments can be seen sometimes.
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