The Monster Maker (1944)

Dr. Igor Markoff, an overbearing scientist, injects test subjects with an acromegaly serum, a glandular concoction that causes bones in their extremities and parts of the skull to grow out of proportion. Recipients become hideously deformed. After noting that famed concert pianist Anthony Lawrence's daughter Patricia strongly resembles his dead wife, he becomes obsessed with winning her favor. She already has a serious boyfriend, Bob Blake, who is also Lawrence's tour manager. Patricia rejects Markoff's advances. Still unwilling to give up, Markoff manages to injects her father with his acromegaly serum. Anthony's fingers start deforming such that he can no longer play and his face begins to grow distorted. In return for the antidote, Markoff intends to extort a fortune and demand the hand of the musician's pretty daughter. Markoff's long-time female assistant, Maxine, has secretly harbored a love for him for years. She is most distressed when she overhears of his intentions. So are Patricia and her boyfriend.