VOLUME FRACTION OF DENSE-CORE GRANULES CORRELATES STRONGLY WITH SURVIVAL IN DISSEMINATED (STAGE-IV) NEUROENDOCRINE CELL CARCINOMAS OF THE LUNG OF THE WELL-DIFFERENTIATED AND SMALL-CELL SUBTYPES

In order to verify whether ultrastructural quantitative morphological indices of neuroendocrine cell carcinoma of the lung may help to predict survival in disseminated disease (Stage IV), 21 biopsy specimens were studied. Volume density of mitochondria and dense-core granules was assessed by a conventional point-counting procedure. Survival in months after biopsy was considered the dependent variable of age and of the morphometric parameters, in a multivariate linear regression analysis. The significance level was set at 5%. Survival was positively correlated ip = 0.011, multiple r = 0.686) with volume fraction of dense-core granules (p = 0.0025) and negatively correlated with volume fraction of mitochondria (p = 0.035), and also with age (p = 0.034). Our data indicate that survival is strongly dependent on the degree ofneuroendocrine differentiation and of metabolic activity of tumour cells and that improved prognostic accuracy is provided by the use of quantitative analyses as compared with the conventional subtyping of malignant pulmonary neuroendocrine neoplasms.