[MUSIC] Welcome back to second part of the talk on cystic masses of the pancreas. I'm Korosh Khalili, and I work at the University Health Network, and Mount Sinai Hospitals, in the division of abdomen. And also I'm an assistant Professor at the University of Toronto. The most common variety of IPMNs is the side-branch variety. And this is a cluster of connecting tubular cysts, and we may identify communication
with the pancreatic duct. Again, the pancreatic duct may be distended, and if it is, it'll be distal, or downstream from the side of attachment, or diffuse dilatation. These can occur anywhere within the pancreas, but they have couple of typical locations such as the uncinate process within the pancreatic head, and also within the distal
tail of the pancreas. Both on this ultrasound and on the MR image, we can identify the cystic lesion within the pancreatic body. [BLANK_AUDIO] And when we look at these more carefully, we can see the communication of the cystic lesion with the pancreatic duct both on the ultrasound and also more easily on the MRCP.
[BLANK_AUDIO] 75% of side-branch IPMNs are benign. But resection is recommended when they reach a size greater than 3 cm. When they have a solid mural nodule, then there's dilatation of the main pancreatic duct, when the patient is symptomatic, or if the patient is quite young, and/or the lesion is in a easily resectable area.
[BLANK_AUDIO] The combine [INAUDIBLE] of IPMNs has typical imaging features of both types, and the prognosis is similar to the main duct type. That is, majority of these tend to have malignant potential and total pancreatectomy is recommended for both. So these MRCP images are of two different patients. The top image shows a very severe disease where we can see marked
dilatation of side-branches and the main pancreatic duct, and also nodules that are protruding into the pancreatic duct. In the less severe variety in this patient, we can see that there are several side-branch of lesions, which are quite large, and there is dilatation of the main pancreatic duct as well. Both of these patients had total pancreatectomy.
[BLANK_AUDIO] The malignant potential of side-branch type is not theoretical. It does occur once in a while. For example, in this patient we can see there was a cystic lesion in 2002, in the uncinate process, a typical branch for side-branch IPNM. There was communication with the main pancreatic duct as well. So
the diagnosis of side-branch/g IPNM was made, and the patient was offered surgery because he had one bout of pancreatitis. The patient refused surgery and was lost to follow-up, and returned in 2007 now with an infiltrated unresectable large solid tumor. The third most common type of cystic lesions of the pancreas, are the Mucinous Cystadenoma. These almost always occur in women. They're
pretty rarely seen in men. And so when we see a cystic lesion in a man, we can put this diagnosis much lower on our list of possibilities. They also occur in women of younger age. So these are typically called mother lesions, and we can see while there is quite a bit of age range, between 20 to 82 reported, most often during women of age between 30 and 50. These also are pretty uncommon
to occur in the head of the pancreas, and almost always are within the body or tail of the pancreas. A third of mucinous pancreatic cystadenomas are malignant, but they all have malignant potential. And so therefore, all require a surgical referral.
In terms of their morphology, their outer contour is rounded, and
they have a smooth border. They can be unilocular or more often they're multilocular. One wants to look out for enhancement of the internal septations. Occasionally we can identify enhancing Papillary nodules or solid components within the lesions. And also, if they have calcification, the calcification tends to be peripheral. So
on this unenhanced image, we can identify the cystic lesion in a typical location in the body of the pancreas, and when we provide contrast, we can see that there is enhancement of a solid nodule within this. Also look at the outer margin which is nice and round. So very typical appearances for mucinous cystadenoma. Here are
three different patients with mucinous cystadenomas in the pancreatic
body or tail. So in this patient, we can identify just a single thin septation. And these can easily be seen by ultrasound. In this patient we can see several enhancing septations. And in this patient it appears that they have a large solid component. But in fact, this patient presented acutely with pain, and this is acute hemorrhage. So these cystic lesions
can occasionally bleed and be symptomatic. As I mentioned, mucinous cystadenomas have a malignant potential, and occasionally, we can see them behave in a clear malignant pattern. For example in this patient, we can see this infiltrative tumor with metastasis both in adjacent lymph nodes, and also within the liver. [BLANK_AUDIO] The fourth common
This patient has typical signs of chronic pancreatitis including the atrophy of the pancreatic body and multiple calcifications within the pancreatic parenchyma. There's also marked dilatation of the pancreatic duct. So in such a patient, when we see a large cystic lesion, it is not difficult to make a diagnosis of pancreatic pseudocyst. [BLANK_AUDIO] And here is a CT of the same patient, and we can see the calcifications.
So signs of chronic pancreatitis are helpful in making the diagnosis of pancreatic pseudocyst. We followed this patient and on the MRCP, we can see that in about six months the pseudocyst had shrank significantly in size. Notice how large the pancreatic duct is. This is chronic ductal dilatation due to chronic pancreatitis. [BLANK_AUDIO]
This patient also had a bout of acute pain. And we found this cystic lesion within the tail of the pancreas. Because of the history of pain we followed the lesion. And on followup we could see, in a few months, that the cystic lesion had disappeared, but in fact, there was an underlying mass which had grown in size. So there was a mass in retrospect within
the tail of the pancreas. It's an important point to note, that there are important local causes of pseudocysts. And these are pancreatic adenocarcinomas, pancreatic metastases, autoimmune pancreatitis, or intraductal papillary mucinous tumors. All of these can cause blockage of the pancreatic duct and lead to pancreatitis. So whenever we see a pancreatic pseudocyst, it's important to look carefully
at the underlying pancreatic parenchyma to make sure that there is no disease there. Now we're going to talk about how to diagnose
cystic lesions by showing you a large table that has lots of information on it. So we've talked about the oligocystic serous cystadenomas whose diagnosis can be troublesome. The mucinous cystadenoma, the side-branch IPMN, and the pseudocysts. And I know this table appears
very formidable, but we'll go through it, and it actually quite easy to digest. So first three features are age, sex, and location. And these three features are really only useful for the mucinous cystadenoma. In these patients, the age of the patients tend to be lower than the rest of the lesions. They're very uncommon in men, and they're very uncommon in the pancreatic head. So when an
elderly patient, in a male patient, or in a lesion that is located in the pancreatic head, we would consider mucinous cystadenoma as an unlikely possibility. The next feature is the pancreatic cystic contour. Okay. So the contour of the oligocystic subtype and side-branch IPMNs, are lobulated on the outer side. And they're smooth
outer margins for mucinous cystadenomas and pancreatic pseudocysts. In terms of the pancreatic ductal dilatation, the dilatation is uncommon to be seen with/g serous cystadenoma, and also uncommon with mucinous cystadenoma. But if they occur, it's because of mass effect, and occurs upstream to the lesion or proximal to the lesion. With side-branch IPMN the pancreatic ductal dilatation
can be occasionally seen, and if does occur, it tends to be diffused or distal to the lesion. And with pseudocysts, in cases of chronic pancreatitis, there may be diffused dilatation of the pancreatic duct. In terms of communication with the pancreatic duct, it's quite uncommon to see with mucinous cystadenoma. Would be very unusual with serous cystadenoma as well.
But it is quite common to see side-branch IPNM, and also with the pancreatic pseudocyst. Calcification is seen centrally within the serous cystadenomas, and described to be seen peripherally within muscinous cystadenomas. They are uncommon to be seen with intraductal papillary mucinous neoplasms. And they're pretty rare with pseudocyst. If you do see calcification it tends to be within the pancreatic
parenchyma because of chronic pancreatitis. Finally, internal debris has been described as being a common feature within pseudocyst and helpful in differentiating this from the other cystic neoplasms. However, occasionally, mucinous cystadenomas can present with acute haemorrhage, and therefore, internal debris can be seen within them as well. Thank you for joining me
for part two of three of pancreatic cystic neoplasms. [BLANK_AUDIO]