[A case of rapidly progressing lung spindle cell carcinoma presenting as Pancoast syndrome].

We report a case of rapidly progressing spindle cell carcinoma presenting as Pancoast syndrome. The patient was a 59-year-old woman with a chief complaint of right forearm paresthesia. A chest computed tomography revealed a huge tumor in S1 and S2 in the right lung, invading the upper mediastinum and the first rib. A CT-guided lung biopsy was performed. H-E stain of the tissue revealed spindle-shaped tumor cells proliferating diffusely in a streaming pattern without definitive squamous or glandular differentiation. Immunohistochemical stains with CAM 5.2 and vimentin were positive for tumor cells. Based on a pathological diagnosis of spindle cell carcinoma (cT4N3M1, stage IV) she was treated with chemoradiotherapy. Despite treatment, the patient died 6 months after presenting.