Abstract

We report three cases of neuroendocrine tumors of the lung characterized by large pleomorphic cell with frequent mitosis, which show neuroendocrine differentiation by both light microscopy or electron microscopy and iminunohistochemistry. These tumors have been categorized as large cell neuroendocrine carcinoma by Travis et al.(1991) in contrast with non-small cell lung cancer with neuroendocrine differentiation. In the latter, neuroendocrine differentiation is not evident by light microscopy and must be demonstrated by imunohistochemstry or by electron microscopy. The prognosis of large cell neuroendocrine carcinoma, together with non-small cell lung cancer with neuroendocrine differentiation, appears to be worse than cancer without neuroendocrine differentiation and intermediate between atypical carcinoid and small cell lung cancer. Larger numbers of patients will be needed to demonstrate significant differences in survival.

• Keywords: Neuroendocrine tumor;Large cell;Lung;Light microscopy;prognosis