All are TRUE about foregut carcinoid tumors, EXCEPT:

Foregut carcinoid tumors generally have a low serotonin content. They are argentaffin-negative but argyrophilic and occasionally secrete adrenocoicotropic hormone or 5-hydroxytryptophan, causing an atypical carcinoid syndrome. They are often multi hormonal and metastasize to bone. Ref: Harrisons Principles of Internal Medicine, 18th Edition, Page 3058.