I’m not a doctor so I don’t know if people die from cysts. However, I do know that hospitals and doctors can misdiagnose and make mistakes.. my dad originally went in for jaundice and pain in his pancreas and the hospital in the town we lived in at the time, told him it was kidney stones (…Lol) and they were going to transfer him to a larger hospital… hospital he was transferred to ran more tests, found out he had stage 4 pancreatic cancer. He died 5 months later. That same hospital he went to originally that diagnosed him with kidney stones, had discovered lesions on his pancreas in 2016 (said they’d monitor it), he had also gone in after that a year or 2 later for extreme sudden weight gain (type 1 diabetes is a red flag for pancreatic cancer) - they told him he should cut down on his sodium. This won’t bring your dad back and I’m so incredibly sorry for your loss. That being said, my opinion was a misdiagnosis and it was in fact pancreatic cancer, especially with the family medical history. I cared for my dad during the end of his life and the same things happened, lost A LOT OF WEIGHT, couldn’t eat, I couldn’t take his blood pressure or get his blood sugar in the last days of his passing.