28
Liver and Pancreas
degree o f d iffe re n tia tio n m ay vary fro m neoplasm s w ith w e ll-
defined ductal structures to those w ith anaplastic u n d iffe re n ti-
ated cells in o th e r tum ors. P leo m o rp hic g iant cell carcinom a
and adenosquam ous carcinom a also occur and are u n c o m m o n
m a lig n a n t neoplasm s o f the pancreas. As can be expected, FN A
smears fro m carcinom as o f the pancreas fro m d iffe re n t patients
m ay e xh ib it various cytom orp holog ic patterns and features, as
discussed in the fo llo w in g sections.
Well-Differentiated Ductal Adenocarcinoma
Aspirates fro m ductal adenocarcinom as o f th e pancreas o f the
w e ll-d iffe re n tia te d type are u su a lly cellular. T u m o r cells occur
in cohesive groupings. T he y tend to fo rm large fla t sheets
(Fig. 2 8.8 6 )
o f honeycom b
ductal
e p ith e liu m w ith
nuclei
located w ith in sharp ly delineated cell borders (Fig. 2 8.8 7 ).
T h e ir nuclei are larger th a n those o f n o rm a l ductal cells and are
ro u n d o r ovoid , w ith s lig h tly coarse c hrom a tin . The v a ria tio n in
Fig. 28.86 Well-differentiated ductal adenocarcinoma of the
pancreas. Abundant sheets of ductal epithelium with minimal nuclear
atypia aspirated from an organ composed of mainly pancreatic acini. FNA
smear (Romanowsky x LP).
Fig. 28.87 Well-differentiated ductal adenocarcinoma of the
pancreas. A monolayer sheet of ductal type epithelium with honeycomb
cell borders and slight variations in nuclear size, aspirated directly from
the pancreas, an organ normally composed of mainly acini. FNA smear
(Papanicolaou x HP).
nuclear size is noted in som e clusters, and u n ifo rm ity o f nuclei
is seen in o th e r groups. C arcinom as o f the pancreas w ith p ro m -
in e n t secretory a ctivity were u n c o m m o n . O n som e occasions,
it m ay be d iffic u lt to d iffe re n tia te th e atypical ductal cells o f
chronic pancreatitis fro m th e neoplastic cells o f w e ll-d iffe re n ti-
ated carcinom a in FN A smears. T he in d iv id u a l cells o f these tw o
c on d itio ns m ay lo o k alike in the smears. However, the pres-
ence o f a large q u a n tity o f large sheets o f ductal e p ith e liu m in
the absence o f lym phocytes and plasm a cells,126 the find ing s
o f three -d im en sio na l, tig h tly packed cell clusters w ith irregu-
la rity in cell arrangem ent, and anisonucleosis w ith in th e same
sheets o f ductal e p ith e liu m are ind icative o f m alig nancy (see
Table 28.2) .127
Key features of ductal adenocarcinoma, well
differentiated
• A b u n d a n t sheets o f d u cta l e p ith e liu m w ith h o n e yc o m b
p a tte rn w ith a niso n uc le osis;
• Absence o f ly m p h o p la s m a c y tic in filtra tio n ; and
• R ule o u t d u c tu la r p ro life ra tio n in a u to im m u n e pancreatitis.
Moderately Differentiated Adenocarcinoma
C ytolog ic diagnosis o f ductal adenocarcinom as o f the pancreas
o f the m od erately d ifferentiated type is easy and straig htforw ard
because the tu m o r cells are fra n k ly m a lig n a n t (Fig. 28.8 8 ) . Large
tu m o r cells occur in cohesive clusters, noncohesive groupings, o r
singly. The y are b izarre-looking , w ith p leo m o rp hism and irregu-
la rity o f the nuclei. T he nuclei vary in size and shape and have a
coarse c h ro m a tin pattern and freq uent p ro m in e n t nucleoli. The
a m o u n t o f cytoplasm is variable, fro m scanty to abundant.
Mucinous Adenocarcinoma
The dism al prognosis and d e rivatio n fro m pancreatic intra ep i-
th e lia l neoplasia in m ucin-p rod ucing ductal adenocarcinom a are
the same as the ductal adenocarcinom a th a t does n o t produce
m ucin. A w ide variety o f patterns can occur. Som e show abun-
dant extracellular m ucin, whereas others show m o s tly intra ce llu -
la r m ucin. Som e have dystrophic goblet cells w ith loss o f nuclear
Fig. 28.88 Moderately differentiated ductal adenocarcinoma of the
pancreas. Obviously malignant epithelium with coarse chromatin and
variations in nuclear size and shape. FNA smear (Papanicolaou x MP).
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