Posterior mediastinal squamous cell carcinoma is rare and may be mistaken for other diseases of the oesophagus if there is no mucosal invasion due to mass compression. We present a 75-year-old man with progressive dysphagia and a posterior mediastinal mass measuring 6.8 6.2 3.5 cm. Endoscopy showed narrowing at 27-33 cm from the incisors and an intact mucosa; extrinsic compression was suspected. Jointly consult with colleagues, then perform right thoracoscopic resection. The planes of the tumor were not clearly delineated and included the azygos arch, esophagus and bronchi, but it was fully removed. Histopathology confirmed keratinizing squamous cell carcinoma; CK(AE1/AE3), CK5/6 and p40 positivity indicated squamous differentiation, and CD5, CD117 and TdT negativity ruled out thymic or lymphoid origins. Systemic imaging did not find a primary tumour, and the lesion was thus diagnosed as a presumed secondary mediastinal carcinoma of unknown primary origin. The patient was uninjured and had not returned within 12 months. This case shows that for posterior mediastinal tumours with oesophageal-type lesions, a combination of radiology, endoscopy, pathology and surgery can be performed in a study.
