RESUMEN
This case is about a 70-year-old man who presented with symptoms and laboratory reports that indicated differentials toward an infectious disease (pneumonia and tuberculosis). A lung mass was found in his chest X-ray and in the computerized tomography (CT) scan of his thorax. A biopsy was taken from the lung mass, and histopathological examination and immunohistochemical staining of the biopsy were done. The results revealed the presence of spindle cell carcinoma (SpCC) with vimentin and cytokeratin positivity. Spindle cell lung cancer is a rare type of non-small cell lung carcinoma, for which all available research indicates a poor prognosis. Due to the rarity of diagnosis, there is a dearth of information about the epidemiology and overall survival of affected patients.