Carcinoid tumors—a re-emphasis of their malignant nature.Review of 140 cases

3 I N C E the early work of Lubarsch,29 in 1888, a primary tumor of the gastrointestinal tract has been recognized that is present most commonly in the appendix, superficially resembles carcinoma upon histological examination, yet is distinctive in appearance and behavior. Oberndorfer, in 1907, used the term "carcinoid" for this tumor because of his belief that the neoplasm was benign, despite its resemblance to carcinoma. Masson and colleagueslg first noted the remarkable affinity for silver salts displayed by the intracytoplasmic granules of the tumor cells and suggested that the lesion be called "argentaffin tumor." Studies ofmore recent years,2lo-36* 46 however, have increasingly emphasized that this neoplasm is not necessarily benign, that local invasion of nodes occurs rather frequently with lesions of certain primary sites, and that distant widespread metastasis is not unknown. Our recent experience with three carcinoid tumors of the rectum39 demonstrated the malignant potentialities of this lesion in that two patients died with extensive metastases, each within two and a half years after the onset of symptoms.