A malignant neoplasm involving the mediastinum. The disease is MONDO_0005843 (mediastinal cancer). Also known as: cancer of mediastinum, cancer of the mediastinum, malignant mediastinal neoplasm, malignant mediastinal tumor, malignant mediastinal tumour, malignant mediastinum neoplasm, malignant neoplasm of mediastinum, malignant neoplasm of the mediastinum.