Signs and Symptoms of Carcinoid Tumors

Carcinoid tumors are slow-growing tumors and most do not cause symptoms until they interfere with daily function or metastasize. Symptoms are often associated with the site of tumor origin and reflect the tumor obstructing organs involved in normal body function but may be less specific if related to carcinoid syndrome

Symptoms for some specific tumors include:

Pulmonary carcinoids are also referred to as bronchial carcinoids. The most common presentation is that of a patient over the age of 50 who presents with a pulmonary mass. Carcinoid lung tumors grow slowly and are more likely to be metastatic if they are large and cells are undifferentiated in appearance. It may be difficult to differentiate these tumors from small cell carcinomas. A syndrome characterized by flushing and wheezing may occur in a subset of patients (carcinoid syndrome).

Symptoms of pulmonary carcinoids are usually related to bronchial obstruction and may include:

• Cough
• Bloody sputum (hemoptysis)
• Wheezing or asthma-like symptoms
• Pneumonia unresponsive to treatment

Other symptoms may include:

• Tremor
• Lacrimation (tearing of the eye)
• Anxiety
• Hypotension (low blood pressure)

If the carcinoid tumor secretes ACTH (adrenocorticotropic hormone), additional symptoms may include:

• Weight gain
• Increased facial and/or body hair

More serious symptoms may include:

• Pulmonary edema (fluid in the lungs)
• Cushing syndrome (a disease caused by the overproduction of the hormone cortisol by the adrenal glands)
• Hemoptysis (vomiting blood)

Up to 80% of lung carcinoid tumors are located centrally in or near central airways and 20% are located peripherally. Lung tumors are less likely than GI tract tumors to release hormone-like substances into the blood.

Pancreatic carcinoid tumors can produce several different substances (e.g., gastrin, insulin) and symptom presentation is usually related to the effects of the prevalent substance that is produced.

This carcinoid is seen primarily in men. Symptoms may be due to compression and include chest pain and indigestion.

Gastric carcinoids account for approximately 4% of all GI neuroendocrine tumors (NETs) and 1% of all gastric cancers. There are three types of gastric (stomach) carcinoid tumors. Those associated with gastrinemia (elevated levels of the hormone gastrin which is produced by the carcinoid cells lining the mucous membranes of the stomach) have a lower malignant potential than those that are not. The categories of gastric tumors include:

• Type I gastric carcinoids account for approximately 70-80% of gastric carcinoids. There are typically multiple tumors that are usually less than 2 cm. in size. Most patients are asymptomatic at the time of diagnosis. This type of tumor occurs most frequently in women over the age of 50. Type I gastric carcinoids are associated with chronic atrophic gastritis (chronic inflammation of the stomach that causes the disintegration of the mucous membranes in the stomach and a reduction in the number of functioning stomach cells) and pernicious anemia (severe anemia caused inadequate production of a substance that is needed for absorption of vitamin B12) and generally is seen in the elderly population. Type 1 gastric carcinoid tumors are characterized by hypergastrinemia (elevation of the levels of the hormone gastrin). Most tumors are benign, however, between 3-5% are metastatic.
• Type II gastric carcinoids account for approximately 5% of gastric carcinoids and are equally distributed among men and women. They are generally seen in patients with MEN I or Zollinger-Ellison Syndrome (ZES) and also involve high levels of gastrin. Although overall these tumors are uncommon, they are seen in up to one-third (33%) of patients with either ZES or MEN I. The majority of these tumors are histologically similar to Type I gastric carcinoids but have a greater malignant potential. It is estimated that regional lymph nodes are involved in 30% of cases and liver metastases are present in 10% of cases.
• Type III gastric carcinoids are called sporadic tumors and are the most malignant of the gastric tumors. Between 15% to 25% of gastric carcinoids are sporadic and are not associated with elevated levels of gastrin. They typically present as solitary large tumors (>2cm) and occur most frequently in men. Sporadic tumors usually exhibit aggressive growth and tend to be already metastatic at the time of diagnosis. Regional lymph node involvement is estimated to occur in up to 50% of cases and liver metastases develop in up to 66% of cases. Approximately 5-10% of patients with Type III gastric tumors develop an atypical carcinoid syndrome which includes:
  • patchy bright red flushing
  • edema of the skin
  • swelling of the parotid (salivary) gland
  • increased tearing of the eyes

In 2000, the World Health Organization (WHO) developed a new classification of neuroendocrine tumors and among the changes that were proposed, a fourth type of gastric tumor was added. It consists of poorly differentiated endocrine carcinomas and mixed exocrine-endocrine carcinomas, meaning it involves both neuroendocrine cells that secrete hormones into ducts that go to the external environment (exocrine) such as sweat glands or salivary glands, as well as neuroendocrine cells that secrete their hormones (such as insulin) directly into the bloodstream. These tumors are typically larger than 5 cm. and are also ulcerated making them very difficult to resect. The prognosis for this type of tumor is poor and the average survival is less than one year.