Pancreatic neuroendocrine tumors can cause life-threatening symptoms from both hormone hypersecretion (over production) as well as tumor growth and invasion. They may also be asymptomatic, however: as the tumors grow they can cause obstructive symptoms or symptoms from growth and invasion of surrounding tissue.
Individuals with pancreatic neuroendocrine tumors may experience symptoms such as abdominal pain, nausea, and vomiting, even though diagnostic scanning shows nothing. Many individuals diagnosed with liver metastases have reported having undiagnosed abdominal pain for several years prior to their diagnosis.
Pancreatic neuroendocrine tumors can secrete a variety of hormones which can cause many clinical symptoms such as flushing and diarrhea. Symptoms occurring together may be classified as a syndrome.
Typical Carcinoid Syndrome
Typical Carcinoid Syndrome is the most common form of Carcinoid Syndrome and is most often caused by midgut carcinoids that have metastasized to the liver. Excess serotonin is the hormone most frequently related to Carcinoid Syndrome. The syndrome is characterized by brief episodes of flushing, diarrhea, cough, wheezing, shortness of breath, heart disease, and in rare cases, pellagra. Flushing and diarrhea are the two main symptoms that are associated with Carcinoid Syndrome. Diarrhea can be mild to severe which may lead to weight loss and lifestyle changes. The flushing may be light pink to a deep red and occurs in the face and in the nipple-line. It may be triggered by stress, alcohol, exercise and certain types of foods.
Individuals with Carcinoid Syndrome can also experience Carcinoid Crisis which can occur spontaneously or be stress induced. A Carcinoid Crisis can be a life-threatening event that requires careful monitoring. Symptoms of a Carcinoid Crisis may include severe hypotension or hypertension, irregular and/or rapid heartbeat, wheezing, prolonged flushing, severe dyspnea (shortness of breath), and peripheral cyanosis (lack of oxygenated blood).
Carcinoid Heart Disease
Pancreatic neuroendocrine tumors can secrete a variety of hormones and vasoactive substances such as serotonin. When these substances are released from liver metastases, the right side of the heart is exposed to them. As a result, patients may experience Carcinoid Heart Disease characterized by plaque lesions in the right side of the heart. Carcinoid Heart Disease can cause right-sided heart failure. Carcinoid Heart Disease is most common on the right side of the heart but can also occur on the left side. While serotonin production is related to the development of Carcinoid Heart Disease, there is evidence of increased cardiac lesions during somatostatin analog therapy. All neuroendocrine tumor patients should be familiar with Carcinoid Heart Disease and discuss appropriate monitoring with their physician.
Certain pancreatic neuroendocrine tumors can secrete adrenocorticotropic hormone (ACTH) causing Cushing’s Syndrome. Cushing’s Syndrome is characterized by excessive upper body weight gain, skin disorders (bruising and poor healing), baldness, and psychological disorders such as depression and anxiety.
Gastrinomas hypersecrete (over produce) gastrin causing Zollinger-Ellison Syndrome. Symptoms of Zollinger-Ellison Syndrome include diarrhea and peptic-ulcers. Patients with Zollinger-Ellison Syndrome may also develop gastric carcinoid as a result of prolonged gastrin hypersecretion.
Verner Morrison Syndrome
VIPomas hypersecrete Vasoactive Intestinal Peptide (VIP) which causes Verner-Morrison Syndrome. Symptoms of Verner-Morrison Syndrome include severe watery diarrhea, which can be life threatening.
Insulinomas hypersecrete insulin and pro-insulin which causes confusion, sweating, dizziness, weakness, and unconsciousness. Prolonged hypoglycemia (low blood sugar) can have permanent impact on brain function.
Glucagonomas hypersecrete a glucose secretion-regulating hormone, which causes skin rash, diabetes, and weight loss.