PART TWO
Diagnostic Cytology
known as the antrum and pylorus. It is contiguous with the first
segment of the duodenum.
The histologic appearance of the gastric mucosa corresponds,
to a large extent, to the gross divisions. Yet, the entire mucosal
surface is lined by very similar appearing mucus-secreting
columnar cells. These cells are characterized by small basally
oriented round-to-ovoid nuclei, abundant cytoplasmic mucin,
and low N/C ratios. Similar cells line the gastric pits that make
up the superficial portion of the mucosa and that join the more
deeply located glands. In the cardiac and antral portions, similar
mucus-secreting cells are present in the glands. In the fundus
and body, the mucus-secreting cells are combined with parietal
and chief cells. In addition, neuroendocrine cells are scattered
throughout the glands.
As the entire mucosal surface is lined by similar cells through-
out the stomach, it is generally impossible to specify, on the
basis of cytomorphologic findings, the portion of the stomach
that was specifically sampled. Brushing smears are dominated
by rather large tightly cohesive aggregates of glandular epithelial
cells. For the most part, these aggregates present as flat sheets
with smooth, sharply defined external edges. This is a reflection
of the maintenance of normal intercellular cohesion. Within the
aggregates, the nuclei are uniformly distributed with essentially
no evidence of overlapping. Cell borders are well defined. These
features combine to create the classic honeycomb arrangement,
reflecting the maintenance of normal polarity. The glandular
nuclei are small, round or slightly ovoid, and pale-staining.
Their chromatin is finely granular, and nucleoli are generally
inconspicuous. Cytoplasm has a granular or slightly foamy
appearance. At the edges of the aggregates, the columnar nature
of the cells may be more apparent, as they are arranged in a
picket-fence pattern (Fig. 14.12). Individually dispersed benign
glandular cells are sparse in brushings but may be more numer-
ous in various types of lavage specimens. The smear background
is clean, with only small numbers of both mononuclear and seg-
mented leukocytes. Elements consistent with intestinal metapla-
sia are not evident in the normal stomach. Squamous epithelial
cells from the oral cavity and esophagus are the most common
contaminants. Food particles, including skeletal muscle fibers,
are also seen with some frequency.
Fig. 14.12 Benign gastric mucosa. The glandular epithelium is arranged
in flat honeycombed sheets with peripheral palisading or a picket fence
arrangement (Papanicolaou x MP).
Overview of Gastritis
For several decades, one of the areas of greatest confusion for
physicians treating patients with GI disorders has been the clas-
sification and diagnostic criteria for gastritis. This has largely
resulted from the relatively poor correlation between endo-
scopic appearances and biopsies and from a relative ignorance
concerning the etiologies and pathogenesis of the various forms
of gastritis. Our concepts concerning the underlying causes
and the histopathology of gastritis have undergone consider-
able evolution since the mid-1980s.111
Foremost among these
changes have been data supporting the role of
Helicobacter pylori
as a major cause of gastritis.
Acute gastritis is a descriptive term frequently used for a
rather vague, self-limited disorder that may be characterized
clinically by epigastric pain, nausea, vomiting, anorexia, and
bleeding. Causes are also quite diverse. The majority of patients
suffering episodes of acute gastritis do not undergo endoscopy.
Even in that small proportion who do undergo endoscopy, the
mucosa shows variable erythema. Usually, cytologic brushings
are not obtained. However, if smears are procured, neutrophils
and fresh blood, as well as normal to mildly atypical glandu-
lar epithelial cells, may be present. The changes of a full-blown
reparative reaction would not be expected unless the mucosa
was also eroded or ulcerated.
The chronic gastritides are much more likely to lead to endos-
copy, biopsies, and cytologic sampling. Today, the chronic gas-
tritides are better characterized as to etiology and histology.112
For the most part, however, they do not possess distinguishing
cytomorphologic attributes. Some forms, such as reactive gastri-
tis (gastropathy), which has been associated with bile reflux and
with nonsteroidal anti-inflammatory agents, may appear totally
normal in brushing smears.112,113
H elicobacter-A ssociated
Gastritis
Over the past three decades, there has been an explosion of data
concerning the potential role of
H. pylori
in the production of
various upper GI tract diseases.111,113-115 Infection with this organ-
ism has been strongly associated with the vast majority of duo-
denal and, to a lesser extent, gastric peptic ulcers. In addition, it
is directly implicated as the cause of chronic diffuse antral gas-
tritis or type B gastritis. Epigastric distress is probably the most
common symptom. Histopathologically, three major alterations
occur within the antral mucosa. These include a superficial dif-
fuse infiltrate of plasma cells, infiltrates of neutrophils within
the epithelial elements, and deeply situated lymphoid nodules
and follicles. In addition, the
H. pylori
organisms are often iden-
tifiable near the mucosal surface; the short curved rods may
appear directly attached to the epithelium or lie just under the
layer of mucus. The changes of intestinal metaplasia are a com-
mon accompaniment.
Cytologic smears from such patients contain large cohesive
aggregates of glandular epithelial cells with or without the mani-
festations of reparative atypia, evidence of intestinal metaplasia,
numerous neutrophils, and
Helicobacter
(Fig. 14.13). The epi-
thelial elements are usually easily recognizable as benign with
the preservation of both normal cohesion and polarity. Intes-
tinal metaplasia manifests as goblet and columnar absorptive
cells. Within the epithelial sheets, goblet cells appear as sharply
delineated clear areas with either a round or barrel configuration
with diameters at least three times that of adjacent columnar
386
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