PART TWO
Diagnostic Cytology
Fig. 28.69 Serous microcystic adenoma of the pancreas. Flat sheets of
Fig. 28.70 Serous microcystic adenoma of the pancreas. Scanty
glycogen-rich simple epithelium. Histology (periodic acid-Schiff stain x HP).
flat sheets of ductal epithelium in a background of serous fluid.
(Romanowsky x MP).
Table 28.3 Comparison of Autoimmune Pancreatitis and Well-
differentiated Ductal Adenocarcinoma in Pancreatic
Fine-needle Aspirates
Autoimmune
pancreatitis
Wel l-d ifferentiated
ductal adenocarcinoma
Acinar cells
Absent
Absent
Ductal cell
Fewer and smaller
sheets of ductal
epithelium
Many groups, vacuolated
cells intermingled with
nonsecretory cells
Cellular
arrangement
Relatively regular,
monolayer
Irregular, tight, three-
dimensional arrangement;
occasional monolayer
Variation in
nuclear size
Minimal
Apparent in some groups
Background
Lymphocytes,
lymphoid tangles, and
plasma cells; fibrosis;
debris may be present
in some passes
Neutrophils sometimes
Fig. 28.71 Serous microcystic adenoma of the pancreas. Bland
epithelial cells that have round or ovoid nuclei, in a sheet arrangement.
FNA smear (Papanicolaou x MP).
com posed o f inn um era b le sm all cavities and few er larger cysts
con tain in g clear fluids. The cavities o f the cysts are lin e d by
cuboid o r c o lu m n a r e p ith elial cells con tain in g ab und ant glyco-
gen (Fig. 28.6 9 ) . U ltra stru c tura l studies have show n th a t features
o f the neoplastic e p ith elial cells are com parable w ith those o f
n o rm a l centroacinar cells.
Cytology
Serous m icrocystic adenom as are d iffic u lt to aspirate. T he aspi-
rates consist o f clear flu id c on tain in g very scanty ductal epithe-
liu m (Fig. 28.70). They occur sing ly o r in cohesive groupings,
in eith er sheets o r palisades (Fig. 28.71) . The e p ith elial cells are
e ith er c o lu m n a r o r cuboid. They have m oderate am ounts o f
cytoplasm and sm all ro u n d o r o vo id nuclei. N u c le o li are ind is-
tinct. A few fo a m y macrophages m ay be present. O th e r cellu-
la r com ponents are rarely seen in the FN A smears fro m serous
m icrocystic adenom as.100 I f th is tu m o r is suspected, one can use
a bigger needle to o b tain a sam ple fo r cell b loc k h isto lo g y to
clinch the diagnosis.
Key features of serous microcystic adenoma
• C lin ic a l: in c id e n ta l fin d in g in m id d le-a g ed p atients.
• C T scan: h o n e yc o m b p a tte rn o f m ic rolac un ae , w ith th in
septae sep arating d iffe re n t segm ents.
• C lea r serous flu id c o n ta in in g scanty sheets o f b e n ig n d uctal
e p ith e liu m .
• C e ll b lo c k is h e lp fu l in e sta b lis h in g th e diagnosis.
Mucinous Cystic Neoplasm
M ucinous cystic neoplasm s account fo r 5.7% o f p rim a ry pan-
creatic tum ors, w ith a fem ale to m ale ra tio o f 90:10 and w ith a
m ean age between 40 and 50 years.101,102 A p p roxim a te ly 7 0 -9 0 %
o f m ucinous cystic neoplasm s arise in the b od y o r ta il o f the pan-
creas. The tum ors are u su ally m u ltilo c u la te d or, rarely, u nilo cu -
lated. C T scans usually dem onstrate a thick-w alled cystic mass
w ith o u t connection to the ductal system. H istologically, the cysts
900
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