Astrocytoma Meaning of Astrocytoma: A tumor that begins in the brain or spinal cord in small, star-shaped cells called astrocytes. Also See: Anthraquinone Antiangiogenesis Agent Acetone Aminolevulinic acid hydrochloride AG014699 AC-TH regimen Anti-IGF1R recombinant monoclonal antibody MK-0646 Auditory Acute paronychia Azathioprine sodium ALSO SEE: Antiprogestin