Ch. 14 - Pancreas & Biliary Tree

Question 1

What are the indications for pancreatobiliary FNA?

Answer 1

Unexplained pancreatic mass, bile stricture

Question 2

How are pancreatic head masses sampled? Pancreatic body/tail?

Answer 2

Head masses are sampled through duodenum, body & tail through the stomach.

Question 3

What complications are associated with pancreatic FNA?

Answer 3

Acute pancreatitis, perforation, cholangitis

Question 4

What chemical testing can be performed on pancreatic cyst fluid?

Answer 4

CEA, amylase, KRAS/GNAS mutations.

Question 5

What are the three normal components of pancreatic parenchyma?

Answer 5

Acinar cells, ductal cells, and islet cells (rare).

Question 6

Describe the cytology of normal pancreatic acini.

Answer 6

Grapelike aggregates with eccentric nuclei, fine granular chromatin, and indistinct cell borders.

Question 7

Describe the cytology of pancreatic ductal epithelium.

Answer 7

Flat cohesive sheets with even nuclear spacing (honeycombing). Should not have visible cytoplasmic mucin!

Question 8

In what context may pancreatitis be sampled by FNA?

Answer 8

Only in chronic pancreatitis which may have mass-forming fibrosis. This is most prominent in autoimmune pancreatitis.

Question 9

Describe the cytology of pancreatic ductal adenocarcinoma (PDAC)

Answer 9

High cellularity, irregular clusters with uneven distribution of cells (“drunken honeycomb”), marked atypia and anisonucleosis (>4:1).

Question 10

Recall some variants of PDAC.

Answer 10

Adenosquamous, undifferentiated (with or without osteoclast-like giant cells), colloid, hepatoid, medullary, signet ring

Question 11

Why is pancreatic intraepithelial neoplasia (PanIN) never sampled by FNA?

Answer 11

It is an in situ lesion and does not present with a mass.

Question 12

Describe the cytology of pancreatic neuroendocrine tumor (PanNET).

Answer 12

Highly cellular with some pseudorosetting, eccentric nuclei with salt and pepper chromatin and rare endocrine atypia.

Question 13

How are PanNETs graded?

Answer 13

By proliferation rate (1 / 2-20 / >20) and by Ki67 (<3% / 3-20% / >20%).

Question 14

What may be functionally secreted by PanNETs, and why is that clinically significant?

Answer 14

Insulin, glucagon, somatostatin, VIP, serotonin, even ACTH and calcitonin. They manifest with clinical symptoms and are often detected earlier.

Question 15

What are some specific markers for PanNET?

Answer 15

Besides the usual neuroendocrine markers, PanNETs stain for Islet-1 and PAX-8.

Question 16

Describe the cytology of acinar cell carcinoma.

Answer 16

Solid-cellular pattern of monomorphic cells with granular cytoplasm (and background granules), smooth nuclei and prominent nucleolus.

Question 17

Describe the cytology of solid pseudopapillary neoplasm.

Answer 17

Cellular aspirate with myxoid/hyalinized vascular stalks. Loose cells have finely vacuolated cytoplasm, grooved nuclei, and inconspicuous nucleoli. Background shows foam cells & debris (cystic degeneration).

Question 18

What are some useful IHC markers for acinar cell carcinoma?

For SPN?

Which has a worse prognosis?

Answer 18

ACC: Trypsin (best), lipase, chymotrypsin, and phospholipase A2

SPN: Alpha1-antitrypsin, PR, CD56, CD10, CD117, and nuclear+cytoplasmic beta-catenin.

ACC has a worse prognosis.

Question 19

Describe the cytology of pancreatoblastoma.

Answer 19

An epithelial component composed of syncytial groups and isolated cells with distinctive “squamoid corpuscles?, and a stromal component composed of primitive spindle cells.

Question 20

Recall some different type of pancreatic cysts.

Answer 20

Pseudocyst, serous cystadenoma, lymphoepithelial cyst, mucinous cystic neoplasm, intraductal papillary mucinous neoplasm.

Question 21

Describe the cytology of pseudocyst.

Answer 21

Thin nonmucinous fluid with inflammatory cells and hematoidin.

Question 22

Describe the cytology of serous cystadenoma.

Answer 22

Low cellularity, clean background, maybe some siderophages and small clusters of glycogenated cells. Hard to diagnose on cytology…

Question 23

Describe the cytology of lymphoepithelial cyst.

Answer 23

Anucleate squames (keratinaceous debris), squamous cells and lymphocytes. May have some cholesterol clefts; overall resembles an EIC.

Question 24

In general, what cyst chemistry profile is expected from benign pancreatic cysts?

Answer 24

High amylase, low CEA, no KRAS or GNAS mutations.

Question 25

Describe the cytology of MCN & IPMN.

Answer 25

Hypocellular, with variable amounts of mucin and variable dysplasia in the epithelial component.

Note: They cannot be distinguished from one another on cytology.

Question 26

Distinguish the clinical features of MCN and IPMN.

Answer 26

MCN: Exclusively affects women, usually in the pancreatic tail. Does not communicate with ductal system.

IPMN: Affects both sexes, involves main duct, branch duct, or both.

Question 27

Describe the cytology of ectopic splenic tissue in pancreas.

Answer 27

Highly vascular, with many lymphocytes. Distinguishing feature is CD8+ vessels on cell block.

Question 28

How can KRAS/GNAS mutational analysis distinguish MCN and IPMN?

Answer 28

KRAS point mutations are seen in both MCN and IPMN. GNAS abnormalities are only seen in IPMN.

Question 29

What are some useful stains to identify PDAC?

Answer 29

SMAD4 (DPC4), p53.

Question 30

Distinguish between the clinical features of serous cystadenoma and lymphoepithelial cyst.

Answer 30

Serous cystadenoma: Affects women, usually in tail of pancreas. Can be microcystic, oligocystic…

Lymphoepithelial cyst: Affects mostly middle-aged men. Can be multifocal.