[Fortuitous diagnosis of an undifferentiated large cell carcinoma during cardiac surgery]

A 57 years old man was operated for aortic valve replacement. During the operation a mediastinal lymph node was biopsed with the result of undifferenciated large cell carcinoma with neuroendocrine features. Three months after surgery the patient died of non-cardiac related reasons, postmorten examination was not performed. Although the primary tumor could not be assessed, probably the lung was the original location. The histological classification of lung cancer is exposed, with special reference in the undifferenciated large cell type with neuroendocrine features.