noun. Any of various neoplasms derived from endothelium.

noun. In pathology, a malignant growth or tumor developed from endothelium.

noun. Any of various mostly benign neoplasms derived from the endothelium of blood vessels or lymph channels

"Cure has resulted in one case of the author following bronchoscopic removal of an endothelioma from the bronchus; and a limited carcinoma of the bronchus has been reported cured by bronchoscopic removal, with cauterization of the base."