Approach to pancreatic masses: Clinical sciences

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Introduction0:00–0:43

Pancreatic masses are either cystic or solid lesions, and can be benign or malignant. Often, these masses are found incidentally during abdominal imaging performed for an unrelated reason.
Cystic pancreatic lesions are more commonly found, and fall into three categories: non-neoplastic pancreatic cysts, pancreatic cystic neoplasms, and inflammatory fluid collections.
Solid masses are less common and include tumors of the exocrine pancreas, such as adenocarcinoma and benign adenomas; as well as pancreatic neuroendocrine tumors.When a patient presents with a chief complaint suggesting a pancreatic mass, your first step is to obtain a focused history and physical examination.

Focused H&P0:43–1:29

Patients often report vague symptoms like abdominal pain that radiates to the back. In some cases, they might have a history of chronic pancreatitis.
The physical exam is typically unremarkable, but depending on the size and location of the mass, you might find tenderness in the upper abdomen.
If you suspect a pancreatic mass, your next step is to order a CT scan of the abdomen and pelvis. A CT scan can help you determine if the mass is cystic, solid, or indistinct.
Understanding these key features will help you narrow down your differential further.Let's start our discussion with pancreatic cysts.

Pancreatic Cysts1:29–1:48

For these patients, your next step is to order labs like liver function tests and a basic metabolic panel, as well as a more detailed CT scan of the pancreas, known as the triphasic pancreatic protocol.
You may also consider an MRI. Alright, first up we have non-neoplastic pancreatic cysts or NNPCs for short.

Non-neoplastic Pancreatic Cysts1:48–2:36

Most patients are asymptomatic. In some cases, history might reveal associated risk factors, such as cystic fibrosis or polycystic kidney disease.
The physical exam is usually unremarkable with a soft, non-tender abdomen; and labs are often normal, although LFTs might be elevated in some cases.
On CT scan with pancreatic protocol, you can expect to find a single, well-defined, non-enhancing, unilocular cyst with no solid elements, no septa, and no communication with the pancreatic duct.
These features are characteristic of NNPCs, which includes retention, true, or simple cysts.Okay, let's move on to another type of pancreatic cyst called pancreatic cystic neoplasms, or PCNs for short.

Pancreatic Cystic Neoplasms2:36–4:21

Although these are benign lesions, they can cause mass effect as they grow in size. Patients typically report unintended weight loss, abdominal pain, nausea, vomiting, steatorrhea, new-onset diabetes, and jaundice.
You can expect to find a non-tender abdomen on examination. Labs are often normal, although some patients may have elevated LFTs and bilirubin levels.
On CT scan, you will likely see a cyst that’s round, well-encapsulated; unilocular or septated; with wall calcifications.
Additionally, most lesions may communicate with the pancreatic ductal system causing a dilated pancreatic duct. With these findings, consider a neoplastic cystic mass.
To confirm the diagnosis, your next step is to obtain a fine needle aspiration, or FNA, of the cystic fluid. Aspiration of non-viscous fluid that contains mucin or glycogen with low levels of amylase and carcinoembryonic antigen, or CEA, is diagnostic of PCNs.
Here’s a clinical pearl! There are three main types of PCN: intraductal papillary mucinous neoplasm or IPMN; mucinous cystic neoplasm; and serous cystadenoma.
Although these are all benign, certain subtypes like main-duct intraductal papillary mucinous neoplasms carry higher malignant potential.
For that reason, the majority of these subtypes are surgically resected.Alright, let’s go back and talk about our final type of pancreatic cystic lesions, inflammatory fluid collections.

Inflammatory Fluid Collection4:21–5:27

These are walled-off collections of fluid that tend to form as a complication of repeated episodes of pancreatic inflammation.
So, history might include chronic pancreatitis, alcohol use disorder, or both. Symptoms can be similar to pancreatitis, such as abdominal pain, nausea, vomiting, and steatorrhea.
Jaundice might be present in severe cases. In these patients, your physical examination will reveal abdominal tenderness and distention, and labs often show elevated LFTs.
The CT will likely show an encapsulated, fluid-filled collection adjacent to the pancreas. If these are your findings, consider an inflammatory cystic mass and order an FNA to confirm.
FNA results that show high amylase, necrotic tissue, and pyogenic fluid are consistent with an inflammatory fluid collection, such as a pancreatic pseudocyst or a pancreatic abscess.Now that we’ve discussed the cystic lesions, let’s move on to solid pancreatic masses.

Solid Pancreatic Masses5:27–6:00

In general, solid pancreatic lesions are more concerning because of the elevated risk of malignancy. So, timely diagnosis and intervention is very important.
If you see a solid pancreatic lesion on initial CT scan, your next step includes a detailed history and physical examination, labs like CMP and tumor markers such as CA 19-9 and CEA; as well as a more detailed imaging like CT pancreatic protocol.Alright, let’s talk about the exocrine tumor of the pancreas first.

Pancreatic Adenocarcinoma6:00–7:10

The most serious type is pancreatic adenocarcinoma, which is the most common type of pancreatic cancer. History often includes unintended weight loss; abdominal pain; nausea, vomiting, and steatorrhea; new-onset diabetes; jaundice; and pruritus.
Physical exam might reveal cachexia; a non-tender abdomen; Courvoisier sign, also known as painless jaundice; and Trousseau syndrome, also known as migratory superficial thrombophlebitis.
Labs often show elevated bilirubin, CA19-9, and CEA. Additionally, the CT typically reveals a poorly defined, hypodense solid mass; often with the double-duct sign, meaning dilatation of the pancreatic duct, or both the pancreatic and common bile duct.
All of these findings together raise a serious concern for pancreatic carcinoma. Next, order a biopsy of the mass.
If the biopsy results show malignant cells, your diagnosis of pancreatic adenocarcinoma is confirmed.Moving on, let’s talk about pancreatic neuroendocrine tumors, or PNETs.

PNETs7:10–9:23

These tumors tend to be functional and cause symptoms related to the hormone they secrete. For example, the most common type of PNET is insulinoma, characterized by the Whipple Triad, which includes symptoms of hypoglycemia, plasma glucose lower than 55 mg/dL, and symptoms of hypoglycemia that are relieved by glucose administration.
The second most common PNETs are gastrinomas, which can cause Zollinger-Ellison syndrome marked by abdominal pain, gastroduodenal ulcers and diarrhea.
Other rare PNETs include VIPoma, which can cause WDHA syndrome, characterized by watery diarrhea, hypoglycemia, and achlorhydria; glucagonoma, which can cause new-onset diabetes; and somatostatinoma, which can cause gallstones.
Patients typically have a soft, non-tender abdomen. Be sure to also examine the skin since necrolytic migratory erythema is characteristic of glucagonoma.
Labs generally show anemia with glucose and electrolyte disturbances, which can vary depending on the type of PNET. On CT, you will likely see a well-defined small tumor, which is usually hypervascular and more prominent on the arterial phase.
Here’s a clinical pearl! Most of these neuroendocrine tumors are commonly found at the tail of the pancreas, though gastrinomas are usually found in the head, in what is known as the gastrinoma triangle, sometimes called the Passaro's triangle.
Now, if you suspect a PNET, your next step is to order specific labs that test for the peptide released by the tumor, which should include serum glucose, insulin, somatostatin, VIP, and gastrin levels.
Also order a biopsy of the mass. The laboratory results may show hyper- or hypoglycemia, or elevated insulin, somatostatin, VIP, or gastrin, which, along with the biopsy, should confirm your diagnosis of the specific subtype of pancreatic neuroendocrine tumor.

Benign Adenoma9:23–9:51

Finally, let’s go back and talk about our benign tumors like an adenoma. These are typically asymptomatic; however, if they are large in size, they can cause mass effect like abdominal pain, nausea, and vomiting.
Physical examination and labs such as LFTs and bilirubin are typically normal; while CT will show a simple mass with no suspicious features of malignancy.
With these findings, you can diagnose a benign adenoma.Alright, as a quick recap… Pancreatic masses can be cystic or solid, and benign or malignant.

Review9:51–10:22

Cystic pancreatic lesions are mostly benign and include non-neoplastic pancreatic cysts, pancreatic cystic neoplasms, and inflammatory fluid collections.
Meanwhile, solid pancreatic masses can be malignant adenocarcinomas, functional like neuroendocrine tumors, or benign adenomas.