The fluid-filled cysts, which are usually harmless and symptomless, are typically found in young adults aged 20 to 30, with three females diagnosed to every one male.
Hoping to undergo surgery within the next few weeks, Renee will endure a complex 10 to 12 hour procedure that requires up to eight neurosurgeons.
Diagnosed in March last year, a month into her Health Science studies at Massey University Wellington, majoring in psychology, Renee was in a lecture when she briefly lost her vision.
"For a while I'd been getting stabbing pains in my head, mostly behind my eyes, and migraines that made it impossible to get out of bed some days because it felt like my head was going to explode."
Having continued with her day, a further fright came when she lost her breath while walking from campus to a nearby supermarket.
After a CT scan at Wellington Hospital, which doctors said did not show anything unusual, she went home, where she missed four phone calls from the hospital.
"They left a message saying they'd found something and I needed to go back in.
"That was one of the worst moments throughout all this because it was in a message and I couldn't ask anything.
"I was in shock there was something in my brain."
An MRI scan identified a benign pineal cyst but because pineal cysts do not usually cause symptoms, doctors said the discomfort was likely a pressure headache.
Over a stretch of five months, Renee endured a series of trial treatments to relive the pain, including having a pressure monitor inserted in her head, an injection in her head to shut off the nerves, injections in her stomach, oxygen therapy and oral treatment from home.
"I had one drug that made it so I couldn't feel my hands, feet and face.
"At night it felt like there was a blanket over my face."
Renee said throughout the treatments, which were unsuccessful, she believed the cyst was the cause of the pain.
In October, as surgeons conducted a bypass in her brain, they found that the cyst was blocking a part of her brain.
"They cleared that and went to drain the cyst but pulled back because it was too risky."
Her third operation, in February this year, included finally draining the cyst, resulting in Renee being pain free after almost a year.
"It was the most amazing feeling I've ever felt in my whole life."
Two months pain free, Renee was "over the moon" to have secured a job at a small domestic airline in Wellington but, after a month in her new role, the sharp pains returned.
"I was at work when I lost my vision again."
Four weeks later, while extremely unwell in hospital, Renee blacked out and remained unconscious for just under a minute, waking to a team of doctors.
An MRI scan showed the cyst had refilled.
"They're doing the big surgery now because, finally, they can say the cyst is the reason for my pain since I was doing really well after they drained it and now that it's back, I have the same symptoms."
Renee, who has coped with the ordeal by "being optimistic" will meet with surgeons in the next few weeks to discuss the risks associated with the surgery.
Currently flatting in Wellington's Island Bay, Renee, who spent her time volunteering at the Ronald McDonald House while sick, was remaining upbeat.
"I get good days and bad days," said the boxer, yoga enthusiast and runner, who regularly entered charity runs before becoming sick.
"The worst part for me throughout this has actually been seeing everyone else upset."
Another challenge, she said, had been losing the ability to fill her days with the things important to her.
"Physically I'm a trooper but emotionally, I'm quite a go getter and always busy, so it is hard feeling that there's no purpose for you."
She said after surgery, her goal was to return to study and, ultimately, the buzz of everyday life.
"For now though, I'm just trying to stay positive and take it as it comes."
To make a donation and help relieve Renee's financial pressure as she recovers, visit the Givealittle page www.givealittle.co.nz/cause/reneekiri.
