Carcinoids of the Appendix : A Case Report, Combined with Statistical Analysis of 142 Cases of a Japanese Series

A case of an appendiceal carcinoid in a 55.year-old female is described as a typical clinical and pathologic model, followed by a statistical analysis of 142 cases of appendiceal carcinoids reported in the Japanese and registered in the Niigata Registry. The analysis includes the incidence of appendiceal carcinoids, sex differences and age distribution, clinical manifestations, sizes of the tumors, metastases, the significance of silver impregnations, serotonin activity and an unusual histologic pattern of the goblet cell type and related varieties comprising 28.7% of the 142 appendiceal carcinoids. A statistical comparison was attempted between goblet cell carcinoids (Group A: n=43) and non-goblet cell carcinoids (Group B: n=98) when judged worthy of evaluation. Statistical significances were noted between these two groups in the male/female ratio, tumor-size distribution, rate of metastases and sites of involvement of the appendix. The low incidence of appendiceal carcinoids - 6.6% of 2,156 digestive carcinoids - as compared to carcinoids in other organs was thought to be largely influenced by background factors and not necessarily a faithful representation of the true occurrence of appendiceal carcinoids. Small-sized carcinoids measuring 10 mm or less comprised 60.0% of 95 cases. Of 76 cases with tumors 20mm or less, 3 showed lymph node metastases and one had a focus of peritoneal involvement. The usefulness of silver impregnation techniques for diagnosing these tumors was reflected by a high rate of positive response of Grimelius' argyrophilia, indicating 93.7% of 63 cases, as well as by a high rate of argentaffin cell type variety showing 68. 0% of 50 cases. The goblet cell type is further briefly discussed as a composite B and a histologic type C variety of carcinoi