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Since 2005, Greys Anatomyhas been a whirlwind of emotions for all those invested in what goes on within Grey Sloan Memorial. Thirteen seasons later and we have watched characters come and go. Some tragically succumbed to death, while others pursued their career in Zurich alongside forgetful interns. Nonetheless, the frequent change of cast members makes it easy to overlook past patients behind this Seattle medical centers walls.

Demi Lovato: The Sorry Not Sorry songstress made her Greys debut back in 2010 while she was still starring on Disney Channels Sonny with a Chance.Lovato portrayed Hayley May, a character who found herself on the verge of complete insanity due to a hole in her ear drum that forced her to hear each and every little thing that went on in her body. Together, Alex and Lexie discovered the teens diagnosis of paranoid schizophrenia was actually superior Canal Dehiscence syndrome.

Keke Palmer: Another former Disney diva also guest-starred on the long-running ABC series. You can catch Palmer as Sheryll Jeffries back in season 10 on an episode titled We Gotta Get Out of This Place. Sheryll is a pregnant teenager that has come to the hospital on her own seeking to participate in Christina Yangs clinical HLHS trial. The runaway and mother-to-be desperately fears that her heart is not quite strong enough to give birth.

Mandy Moore: Prior to breakout family drama series This Is Us landed 11 Emmy nods, Moore contributed her talents to four episodes of Greys, transitioning from the sixth to seventh season. The actress plays the role of Mary Portman, an admitted patient during the fatal hospital shooting. Alongside Bailey, the two are traumatized from witnessing the death of resident Charles Percy. Just only months later, Marys time on Earth is unexpectedly cut short as well.

Dylan Minnette:Probably best known as the character of Clay Jensen in Netflixs hit show13 Reasons Why, (which also stars Greys own Dr. Addison Montgomery)you may have not recognized an incredibly youngMinette from season four. Here, he portrays Ryan, a hearing-impaired boy whose case substantially improves after McSteamy does what he does best and builds him a pair of ears. *cue so he can listen to Hannah Bakers tapes joke*

Wilmer Valderrama:In more recent cameos, the That 70s Show alum appeared with a recurring role during season 12 as Kyle Diaz. Kyle is a M.S. patient and musician, who is sent to the hospital after a tremor in his hand prevents him from further touring. But, he ends up becoming romantically involved with Stephanie Edwards. This specific loss in ShondaLand wasimmensely heartbreaking.

Liza Weil: ThisGilmore Girls actress played Alison Clark in season fives finale Heres to Future Days. Like Izzie, Clark too is a cancer patient; however, she is dealing with the latest stages of the disease and provides Iz with insight during an extensive chemotherapy session. Like any episode of Greys you will ever watch, be sure to have a few tissue boxes at hand before you emotionally dive into this cryfest.

Abigail Breslin: Following her time on the big screen in the 2006 comedy Little Miss Sunshine, Breslin made her debut on season three as Megan Clover. Clover is a foster child who claims she has super powers due to her insensitivity to pain. This episode accurately displays just how incredible Alex Karev is with kids, as he demolishes the young girls apprehensive feelings and successfully goes about her operation, repairing massive internal injuries.

Sarah Paulson:Hollywoods beloved Sarah Paulson acts as a young Ellis Grey in season sixs episode The Time Warp. Due to the Emmy award-winners dedication to filming FXs American Horror Story, Paulson was unable to suit up for the role again in season 11. Instead, Army Wives Sally Pressman took her place for a series of flashbacks that better explain Ellis love affair with Richard Webber. As they say, the show must go on.

Kyle Chandler: To be honest, revisiting this season two cameo stings. The Friday Night Lights actor fulfilled his guest appearance duties by portraying Dylan Young, a bomb squad member who helps ease Merediths nerves so she can remove an explosive out of a patients chest. Mer saves the bazooka builder without sustaining any serious injuries herself, but Dylan isnt quite as lucky. Although, he does appear in the next season to coach Meredith in the afterlife following her drowning accident.

Jana Kramer: Before she wasOne Tree HillsAlex Dupr or a country star, Jana Kramer played the role of Lola on a two-part episode of season fourtitled Freedom. Her character came to the hospital with a young man named Andrew who tried to impress her by laying in cement. Though the romantic feelings werereciprocated on Lolas end, she didnt want to act on them due to what her friends might think or say. After Andrew nearly dies because of this foolish stunt, she puts her ego aside and sits by his bedside, also throwing in a kiss.

Who has been your favorite celebrity spotting in the series to date? Or, who would you like to see make a guest appearance this upcoming season? Keep the conversation going in the comments below!

Season 14 ofGreys AnatomybeginsThursday, September 28 at 8PM EST with a two-hour premiere.

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