RESUMO
Modern immunohistochemical and DNA cytochemical analyses of gastro-intestinal carcinoids have yielded results that have increased our knowledge of the biological properties and the histogenesis of these theoretically and practically so fascinating kinds of neoplasm. Carcinoids in different anatomical localisations were found to show marked differences with regard to their neurohormone peptide immunoreactivity pattern and their ability to evoke clinical signs and symptoms of hormone overproduction. This can be of great help to the practising pathologist when he tries to predict the anatomical site of an unknown primary tumour from the results of this histopathological assessment of a metastatic nodule of a carcinoid. The DNA distribution pattern in the nuclei of carcinoid tumour cells is a tool in the histopathological assessment of the neoplasm that seems to be of some value in predicting the subsequent clinical course of the disease. This conclusion is based on the results of a pilot study of 8 cases of ileal carcinoids with liver and lymph node metastases. It was found that 4 cases with a rapidly progressive fatal disease had a higher proportion on non-diploid tumour cell nuclei than 4 cases still alive and at full work 5 years after the diagnosis of liver metastases. However, the number of aneuploid tumour cell nuclei was negligible in both groups.