Background: Metastatic carcinomas to the upper jaw region are very rare and unfortunately occur in advanced stages of malignancies. Pancoast tumor is a challenging subset of lung carcinoma commonly followed by distant metastasis. Since the metastatic lesion of our patient was very huge and unusual, we decided to report the case. Case Presentation: Our patient was a middle-aged heavy smoker male with a history of unresectable pancoast tumor. He was referred to the dental clinic with an expanded maxillary metastasis involving the bone and sinus region as well as oral soft tissues. To confirm the primary site of his malignancy, immunohistochemical staining was performed. Conclusion: Distant metastases of a pancoast tumor are more frequent when the primary tumor is unoperable and bone involvement is one of the early manifestations of disease
