Pathology
Pathological tests help in the diagnosis of pancreatic cancers and determine the stage of the tumour after it has been removed.
These tests include blood tests to look for elevated levels of bilirubin, pancreatic hormones and tumour markers. Biopsies also are performed to confirm the diagnosis or spread of a tumour. Pathological analysis is also performed on tumours that have been removed by surgery.
How are pancreatic biopsies taken?
The best way to biopsy the pancreas is via endoscopy. This is commonly performed by an interventional gastroenterologist using a technique called Endoscopic Ultrasound (EUS). Samples of the pancreatic and bile ducts can also be taken during an Endoscopic Retrograde Cholangio-Pancreatogram (ERCP).
More rarely biopsies can be obtained of the pancreas or liver by an interventional radiologist using an ultrasound or CT scanner.
How long does it take to get the results of these biopsies?
For straight forward cases, this may take 2 to 3 business days. For more complicated cases, additional testing may be necessary and the result may take more than a week to obtain.
How much tissue is removed for a biopsy?
Only a small amount of tissue is removed, measuring approximately 10 x 2mm.
Are there any risks in biopsy of the pancreas?
There is a small risk of bleeding and pancreatitis when biopsies are taken of the pancreas.
Why is a biopsy of the pancreas not always performed?
A biopsy is always required if chemotherapy is to be given prior to surgery. In cases where surgery is the first treatment, a biopsy is not always required as there is a small risk of complications and delay in definitive treatment.
How are the biopsies interpreted?
These are processed in the pathology laboratory over a 1 to 2 day period, prior to being interpreted under a microscope by a specialist anatomical pathologist. In certain circumstances, additional testing via special techniques may be required to reach a definitive diagnosis.
Are there any other tests that can be done on the biopsies?
Yes, larger core biopsies can be used for molecular testing of tumours (see below).
When a pancreatic tumour is removed and sent to the lab, what happens to it?
The process of pathological examination contains many steps. Initially, the tissue is immersed in formalin for approximately 24 hours to aid in examination. The specimen is then examined by a doctor, who performs a macroscopic examination and selects appropriate tissue for examination. In the case of the pancreas, usually all of the pancreas is examined. Over the next few days the selected tissue is chemically processed, embedded in wax blocks, cut with a microtone, placed on glass slides and then stained with dyes to highlight the various elements of tissue. Finally at the end of this process, the specialist anatomical pathologist examines the case and writes their report.
Are samples at the Sydney Pancreatic Centre processed in a different way from other centres?
Pancreatic specimens are embedded in specialised large tissue blocks which allows for better visualisation of the pancreas. This technique ensures that the entire tumour is adequately assessed and aids the pathologist is determining the extent of spread.
How long does it take to get a result from this pathology?
Approximately 1 to 2 weeks. Occasionally, difficult cases may take longer to report.
Why does it take this long to get the pathology result?
The large tissue blocks used in this laboratory, due to their size, require additional time for processing. In some cases, further time is required to perform additional tests to arrive at an accurate final diagnosis.
How is the stage of the tumour determined?
The stage of the tumour is assessed by measuring the size of the tumour, whether there is any tumour in lymph nodes and whether the tumour has spread to surrounding structures.
Can my tumour be used for research purposes?
At the Sydney Pancreatic Centre, patients who have surgery may also choose to donate parts of the tumour that are not needed for diagnostic tests so the samples can be used to further pancreatic cancer research. Prior to your procedure you will have the opportunity to discuss this with your doctor. Should you agree to participate, a small amount of tumour is taken from the specimen (after it has been processed) and stored for future research purposes. This research will not benefit you directly but may benefit others who have a similar condition in the future.
What is molecular testing of tumour specimens?
Your doctor may recommend additional molecular testing on the tumour sample to look for changes in specific genes and proteins. Some molecular tests can be done in your local hospital laboratory. For other tests, the sample may need to be sent to an independent laboratory for analysis. For pancreatic cancer, testing may be done for high microsatellite instability (MSI-high), which may also be called a mismatch repair deficiency, and/or a specific genetic change called an NTRK fusion. These tests may help doctors determine your treatment options. However, these genetic changes are not common in pancreatic tumours.
Molecular testing may allow for a “personalized” approach in respect to the chemotherapy required and is an area of increasing interest and scientific focus.
Talk with your doctor for more information