Since the publication in 1906 of Rolleston and Jones's review of "Primary Malignant Disease of the Vermiform Appendix" there have been numerous case reports and reviews of the subject. Rolleston and Jones clearly differentiated between " columnar-celled carcinoma, like that met with in the large intestine," and "spheroidal-celled carcinoma." It was not until Gosset and Masson (1914) and Masson (1928) brought into prominence the argentaffinstaining properties of the spheroidal-celled tumours that a distinction was generally drawn. The term "carcinoid," introduced by Oberndorfer in 1907 to refer to similar tumours of the small intestine, has been generally accepted for these not uncommon yellow argentaffin tumours having their origin in the Kultschitzky cells of the crypts of Lieberktihn. They are all pote.itially malignant (Willis, 1948), although both primary and metastatic argentaffinomas