Estelle Harris

Two of Estelle's "Seinfeld" costars, Jason Alexander and Julia Louis-Dreyfus, just took to Twitter and penned heartfelt tributes. Jason said, "One of my favorite people has passed - my tv mama, Estelle Harris. The joy of playing with her and relishing her glorious laughter was a treat. I adore…

Estelle Harris -- who famously played George Costanza's mother on "Seinfeld" -- says she's ALL GOOD after doctors found cancer on her nose ... telling TMZ they "got it all out." Harris -- who also voiced Mrs. Potato Head in the "Toy Story" movies -- was out at the Arclight theater in Hollywood…