Large cell neuroendocrine carcinoma of the lung

Large cell neuroendocrine (LCNE) carcinomas of the lung are a newly recognized, highly aggressive and frequently misdiagnosed entity. We report a case of stage I LCNE lung carcinoma initially misdiagnosed as large cell undifferentiated carcinoma or poorly differentiated adenocarcinoma. The tumor was very extensively necrotic and its neuroendocrine differentiation was only demonstrable with immunohistochemical staining with PHE-5 monoclonal antibody and with antisera against synaptophysin and calcitonin. ACTH, somatostatin and neurofilaments were not demonstrable. The clinical course was ominous and the patient died within 17 months. The reason for this rapid fatal outcome could be ascribed either to the neuroendocrine phenotype of the tumor, or to the extensive necrosis, or both.