Carcinoid syndrome - Skin
Classically, the gastrointestinal tract, respiratory system, cardiovascular system, and the skin are involved. The most common site of origin of carcinoid tumors is the gastrointestinal system (approximately 90% of tumors arise here), where they occur in locations such as the small intestine, colon, and appendix. Following this, another common location is the lungs, especially, the trachea and bronchi.
When the heart is involved, the term carcinoid heart disease is used. Cardiac abnormalities that occur in carcinoid heart disease arise due to the effects of vasoactive substances released by the tumor cells. The tricuspid and pulmonary valves are commonly affected, resulting in pulmonary stenosis and tricuspid incompetence.
The symptoms will vary according to which biogenic amines and peptides are secreted, but the most predominant symptoms are cutaneous flushing, diarrhea, wheezing, and palpitations. 5-HT is thought to cause the diarrhea and cardiac complications, whereas bradykinin, a vasodilator, produces cutaneous flushing, bronchospasm, and increased intestinal motility.
The cutaneous manifestations of carcinoid tumor are varied and include the following:
- Skin changes related to niacin deficiency, which leads to a pellagra-like dermatitis
- Scleroderma-like skin changes
- Cutaneous metastasis
Scleroderma-like skin changes are associated with the carcinoid tumor and are thought to be mediated by serotonin, resulting in dermal fibrosis.
Although the majority of carcinoids are asymptomatic, some of them will cause the classical carcinoid syndrome. Carcinoid syndrome presents when there has been metastasis to the liver and mediators escape into the systemic circulation instead of being metabolized by the liver. This only occurs in 5% of patients with carcinoid tumors.
The time period between onset of symptoms and diagnosis varies for different aspects of the disease. In the case of carcinoid heart disease, it is approximately 2 years, but it may take up to 5 years for the diagnosis to be established.
These tumors are usually discovered incidentally during surgery performed for other reasons. Carcinoid syndrome can occur at any age, but the mean age is between 60 and 70 for tumors of the small intestine and rectum.
The prognosis for patients with carcinoid syndrome is better if there is no concomitant carcinoid heart disease.
Carcinoid crisis is a life-threatening complication of carcinoid syndrome. The crisis is caused by an excessive release of serotonin and other chemicals such as histamines. It is characterized by the sudden onset of prolonged cutaneous flushing, peripheral cyanosis, confusion, dyspnea, and tachycardia.
This condition may be triggered by stress, chemotherapy, anesthesia, hypothermia, hypertension, and may even occur without any apparent triggers.
Carcinoid syndrome is associated with a number of conditions. These include multiple endocrine neoplasia, Zollinger-Ellison syndrome, and atrophic gastritis.
E34.0 – Carcinoid syndrome
35868009 – Carcinoid syndrome