EWSR1 and mucinous adenocarcinoma: After excluding the possibility of a metastatic tumor, differential diagnosis of the primary tumor included several possible types of tumors: chordoma, extraskeletal myxoid chondrosarcoma, myoepithelioma/mixed tumor, benign peripheral nerve sheath tumor showing myxoid change, chondrosarcoma, myxoid liposarcoma, primary pulmonary myxoid sarcoma with EWSR1–CREB1 fusion, pleomorphic adenoma, chordoid meningioma, and mucinous carcinoma.