How do the features of carcinoid tumors vary by location?

Updated: Feb 12, 2019
  • Author: Cameron K Tebbi, MD; Chief Editor: Max J Coppes, MD, PhD, MBA  more...
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Carcinoid tumors can also arise from the Meckel diverticulum, cystic duplications, and the mesentery. Each of these entities has distinctive clinical, histochemical, and secretory features. For example, foregut carcinoids are argentaffin negative and have low serotonin content but secrete 5-hydroxytryptophan (5-HTP), histamine, and several polypeptide hormones. These tumors can metastasize to bone and may be associated with atypical carcinoid syndrome, acromegaly, Cushing disease, other endocrine disorders, telangiectasia, or hypertrophy of the skin in the face and upper neck.

Midgut carcinoids are argentaffin positive and can produce high levels of serotonin 5-hydroxytryptamine (5-HT), kinins, prostaglandins, substance P (SP), and other vasoactive peptides. These tumors have a rare potential to produce corticotropic hormone (previously adrenocorticotropic hormone [ACTH]). Bone metastasis is uncommon.

Hindgut carcinoids are argentaffin negative and rarely secrete 5-HT, 5-HTP, or any other vasoactive peptides. Therefore, they do not produce related symptomatology. Bone metastases are not uncommon in these tumors.

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