Signs and Symptoms of Pancreatic Neuroendocrine Tumor (pNET)

Gastrinomas

These tumors make gastrin, a hormone that tells the stomach to make more acid. Too much gastrin causes a condition known as Zollinger-Ellison syndrome, in which the stomach makes too much acid. This leads to stomach ulcers, which can cause pain, nausea, and loss of appetite. Severe ulcers can bleed. Even if the bleeding is mild, it can lead to anemia (too few red blood cells), which can make a person feel tired and be short of breath. If the bleeding is more severe, it can make stools black and tarry. Severe bleeding can itself be life-threatening.

If the stomach acid reaches the small intestine, it can damage the cells of the intestinal lining and break down digestive enzymes before they have a chance to digest food. This can cause diarrhea and weight loss.

Glucagonomas

These tumors make glucagon, a hormone that increases glucose (sugar) levels. Most of the symptoms of a glucagonoma are mild and are more often caused by something else.

Excess glucagon can raise blood sugar, sometimes leading to diabetes. This can cause symptoms such as feeling thirsty and hungry, and having to urinate often.

People with these tumors can also have problems with:

• Diarrhea
• Weight loss
• Malnutrition ( nutrition problems can lead to symptoms like irritation of the tongue and the corners of the mouth)

The symptom that brings most people with glucagonomas to their doctor is a rash called necrolytic migratory erythema. This red rash with swelling and blisters often moves from place to place on the skin.

Insulinomas

These tumors make insulin, which lowers blood glucose levels. Too much insulin leads to low blood sugar, which can cause symptoms like:

• Weakness
• Confusion
• Sweating
• Rapid heartbeat

When blood sugar gets very low, it can lead to a person passing out or even going into a coma and having seizures.

Somatostatinomas

These tumors make somatostatin, which helps regulate other hormones. Symptoms of this type of tumor can include:

• Belly pain
• Nausea
• Poor appetite
• Weight loss
• Diarrhea
• Symptoms of diabetes (feeling thirsty and hungry, and having to urinate often)
• Gallstones
• Jaundice (yellowing of the skin and eyes)

The early symptoms of a somatostatinoma are mild and are more often caused by other things, so these tumors tend to be diagnosed at an advanced stage. Often, they are not found until they spread to the liver, when they cause problems like jaundice and pain.

VIPomas

These tumors make a substance called vasoactive intestinal peptide (VIP). Too much VIP can lead to problems with diarrhea. This may be mild at first, but get worse over time. By the time they are diagnosed, most people have severe, watery diarrhea.

Other symptoms can include:

• Nausea
• Vomiting
• Muscle cramps
• Feeling weak or tired
• Flushing (redness and warmth in the face or neck)

People with these tumors also tend to have low levels of acid in their stomachs, which can lead to problems digesting food.

Carcinoid tumors

These tumors often make serotonin or its precursor, 5-HTP. Carcinoid tumors often don’t cause symptoms until they spread outside the pancreas. When these tumors do spread, it is most often to the liver. There, the cancer cells can release hormones directly into the blood. This can cause the carcinoid syndrome, with symptoms including

• Flushing (redness and warmth in the face or neck)
• Diarrhea
• Wheezing
• Rapid heart rate

These symptoms often occur in episodes, between which the person may feel fine.

Over a long time, the hormone-like substances released by these tumors can damage heart valves, causing

• Shortness of breath
• Weakness
• Heart murmur (an abnormal heart sound)

Signs and symptoms of non-functioning pNETs

These tumors don’t make excess hormones, so they don’t cause symptoms in early stages and often grow quite large before they are found. Most of these cause problems as they get larger or spread outside the pancreas. Symptoms can be like those from exocrine pancreas cancers, including:

• Jaundice (yellowing of the eyes and skin)
• Belly pain
• Weight loss

Sometimes, as a pNET grows, it can change from making too little of a hormone (non-functioning) to making too much of a specific hormone (functioning), which causes symptoms.

Symptoms caused by the pNET spreading

When pNETs spread, it is most often to the liver. This can enlarge the liver, which can cause pain and loss of appetite. It can also affect liver function, sometimes leading to jaundice (yellowing of the skin and eyes) and abnormal blood test results.

These cancers can also spread to other organs and tissues. The symptoms depend on where the cancer is growing. For example, cancer spread to the lungs can cause shortness of breath or a cough. Spread to bones can cause pain in those areas.