The story
Mid 19th century New Latin, from telo- + angiectasia, reflecting Ancient Greek τέλος (télos, “end, telo-”) + Ancient Greek ἀγγεῖον (angeîon, “vessel, angio-”) + Ancient Greek ἔκτασις (éktasis, “stretching out, extension”) + Latin -ia.
Etymology from Wiktionary, CC BY-SA 4.0.