Week 9 Part 2 - Pancreas and Bile Duct FNA Flashcards
Differential Diagnoses for Pancreas FNA
Pancreatitis vs adenocarcinoma
Pseudocyst vs cystic neoplasm
Unusual tumours e.g. endocrine
Normal Pancreas FNA
Duct epithelium
Acinar cells
Pancreatitis
Common causes are obstruction by a gall stone or alcohol abuse
A clinical diagnosis with serum amylase; Lipase >75u/L
The pancreas may be enlarged or shrunken and nodular
Usually no mass lesion is present but imaging may show a localised abnormality
Chronic pancreatitis is associated with pseudocyst formation
Acute pancreatitis may be peri-tumoral
Pseudocyst
Secondary to enzyme release and fat breakdown in chronic pancreatitis
Amylase raised and CEA normal in cyst contents
If infected may form an abscess
DD - cystic neoplasm
Pancreatitis Cytology
Necrotic debris - “dirty”
Granular calcific debris, lipid droplets
Inflammatory cells (especially macrophages)
Degenerative and reactive atypia
Pancreatic Adenocarcinoma - Clincal
Present with abdominal pain, loss of weight, jaundice
Usually ductal in origin
Usually well to moderately differentiated with a desmoplastic response
5 year survival <5%
Pancreatic Adenocarcinoma Cytology - Architecture
High cellularity with large aggregates, clusters, dispersed cells
Monolayered sheets with marked nuclear enlargement and pleomorphism
Gland formation
Crowding, disorganization, disturbed polarity
Pancreatic Adenocarcinoma Cytology - Cells
Normal/increased N/C ratio
Cell enlargement
Mitoses
Apoptotic debris in tumour cell sheets
Pancreatic Adenocarcinoma Cytology - Nuclei
Enlarged, irregular nuclei with coarse chromatin, hyperchromasia
Large irregular nucleoli
Multinucleation
Ancillary Studies to Confirm Pancreatic Adenocarcinoma Malignancy
Ploidy by flow or image analysis
K-ras oncogene mutation using PCR
P53 tumour suppressor gene mutation using immunoperoxidase
S100P, mCEA and MUC1 (Ma695)
Mucinous Cystic Tumour
A tumour of middle-aged women found in the tail of the pancreas
Not connected with the duct system
Radiology shows a discrete cystic mass
In the fluid CEA levels are raised and the amylase is normal
Mucinous Cystic Tumour Cytology
Variable architectural complexity and cytological atypia
Mucinous columnar cells
Endocrine Tumours
Arise from the Islets of Langhans
Generally found in body and tail of pancreas
May be functional or non-functional
May be benign or malignant in behaviour
Endocrine Tumours Cytology
Single and loose groups, pseudorosettes
Small round nuclei, minor pleomorphism
Nuclei may be eccentric
Neuroendocrine chromatin i.e. speckled with occasional chromocentres
Poorly defined cytoplasm
Endocrine Tumours IHC
Cytokeratins
Broad neuroendocrine markers
- chromogranin and synaptophysin
Specific secretory products
- insulin and gastrin
Endocrine Tumours False Negative Results
The needle may not be in the tumour
Necrosis and inflammation may obscure malignant cells
Desmoplastic tumours may not yield cells
Vascular tumours are blood stained with scanty material
Well differentiated or unusual tumours
Brushings of Pancreatic or Extra-Hepatic Bile Ducts
Patients present with signs and symptoms of obstruction (i.e. jaundice)
Differential Diagnoses
- benign inflammatory stricture vs adenocarcinoma
Provide a definitive diagnosis of malignancy
Avoid more extensive investigations
Allow palliative therapy
Pancreatic Brushings Cytology
Cohesive “honey-comb” sheets of regular
cells
Small rounded or oval nuclei
Columnar row on edge
Pancreatic Brushing/Bile Duct Adenocarcinoma - Architecture
Disorganised sheets
Small acinar groups
Loose aggregates
Single pleomorphic cells
Background of necrotic debris
Pancreatic Brushing/Bile Duct Adenocarcinoma - Cells
Nuclear crowding and high N:C ratio
Nuclear enlargement and irregular outlines
Pancreatic Brushing/Bile Duct Well Differentiated Adenocarcinoma
Cohesive monolayered sheets
Lack the unequivocal nuclear criteria of malignancy
Cell block assessment of architecture may allow a diagnosis of malignancy
Pancreatic Brushing/Bile Duct False Positives
History of biliary catheter or stent, sclerosing cholangitis, bile duct stones or pancreatitis
A small amount of material and degenerative changes (bile)
Inflammation - cholangitis/pancreatitis
Absence of “full house” of malignant features
Pancreatic Brushing/Bile Duct False Positive Causes - Sampling
Failure to cannulate the duct
Insufficient separate brush samples
Poor instruments - poor cell yield
Fibrosis obscures tumour tissue
Pancreatic Brushing/Bile Duct False Positive Causes - Interpretive Errors
Poor slide preparation e.g. air-drying
Small numbers of malignant cells
Well differentiated carcinoma
Special tumour types
Ignoring the smear background
