Yoichi Ajioka

Immunohistochemical and ultrastructural studies of twelve argentaffin and six argyrophil carcinoids of the appendix vermiformis.

Endocrine cell types in 12 argentaffin and six argyrophil carcinoids and in nonneoplastic epithelia of the appendix vermiformis were investigated histochemically, immunohistochemically, and ultrastructurally. The nonneoplastic epithelia contained serotonin (Ser), peptide YY (PYY), glicentin (Gli), neurotensin (Neu), and somatostatin (So) cells in decreasing frequency. Out of 30 nonneoplastic Ser cells examined ultrastructurally, 28 cells were EC1 cells and two were non-EC cells. Eleven of 12 argentaffin carcinoids could be immunostained with anti-Ser serum and all of those 11 were composed almost totally of Ser cells. One of the 11 contained a small number of Neu cells. Ultrastructurally, 11 argentaffin carcinoids were composed predominantly of EC1 and/or ECn cells, and one was composed primarily of non-EC cells. Out of the six argyrophil carcinoids, five were argyrophil, non-argentaffin carcinoids; three consisted almost totally of PYY cells; one consisted of 60% PYY cells, 40% So cells and a few Gli cells; and one consisted of Ser cells alone. Ultrastructurally, the first four of those tumors were composed of D1 and/or L cells and the latter tumor was composed of ECn cells. The remaining one argyrophil carcinoid contained a few Ser-positive argentaffin cells and consisted almost totally of ECn cells which were found in both parts, with and without argentaffinity. It is concluded that the appendiceal carcinoids comprise two distinct groups on the basis of the main constituting cell type: Ser-positive, argentaffin carcinoids, composed of EC cells and peptide (especially of PYY)-positive, and Ser-negative, argyrophil non-argentaffin carcinoids of D1 and/or L cells.

Pathology of Gastroenteric Lesions in Familial Adenomatosis Coli

This paper reports on the findings of high incidences, predominantly neoplastic nature and follow-up data of gastroenteric lesions in Japanese patients with familial adenomatosis coli. Prior to, during or after the colectomy, careful attention should be paid especially to the stomach, duodenum including the papillary region, upper jejunum and lower ileum as well as the thyroid because of high incidences of carcinoma, adenoma and carcinoid.

Histogenesis of Gastrointestinal Carcinoma in Peutz-Jeghers Polyp

Peutz-Jeghers (P-J) polyps (n=367) from 27 patients were histologically examined. There are seen five P-J polyps with adenoma, two P-J polyps with carcinoma in adenoma, a P-J polyp with independent foci of adenoma and carcinoma, a P-J polyp with carcinoma, two advanced primary carcinomas without any remnant of P-J polyp, a carcinoma in adenoma and a pure adenoma in eight patients. Four processes of malignant change of P-J polyp are proposed; (1) malignant transformation of adenoma arisen in P-J polyp, (2) malignant transformation of P-J polyp itself, (3) malignant change in pure adenoma, and (4) de novo carcinoma in normal mucosa. From our data, the first process seems to be the most frequent, and the third to be common in the colon and rectum.