Every episode of the show is named after a famous song. "Almost Grown" is the title of a song written and performed by Chuck Berry.
Chyler Leigh (Lexie Grey) appears to a patient Meg (played by Candice Patton). Both are now part of Arrowverse with Chyler Leigh in Supergirl and Candice Patton in The Flash.
Susan Slome also played a patient in House M.D.