When Sarah Frei shared a sweet Instagram photo of her grandpa holding his two infant great-grandsons in November, she never thought it would end up saving his life.
Frei, 30, posted the shot of her grandfather, John Rzeppa, smiling wide with the babies during the family’s Thanksgiving gathering. At the time, Rzeppa, 91, had a brown patch on his forehead, which doctors initially believed to be a sun spot. However, the photo — particularly the dark patch — caught the attention of Frei’s former classmate, Dr. Jennifer Mancuso, a Detroit-based dermatologist.
“She sent me a private message through the app. She said she had seen pictures of him before and … noticed how much the mark on his forehead had progress over time,” Frei tells PEOPLE. “[She] reached out to me with her concerns … I was amazed that she had taken the time to look into previous pictures to notice the growth and progression of the mark.”
Frei tells PEOPLE that she immediately contacted her mother, Linda Renema. Concerned, Renema took Rzeppa to a dermatologist that Dr. Mancuso recommended. On Dec. 18, about two weeks after Frei posted the photo, Rzeppa was diagnosed with melanoma.
“We were all very shocked,” Frei says. “My mom is a registered nurse and jumped into action immediately. She was extremely disappointed that she had believed the initial consult that there were no concerns.”
Having overcome prostate cancer in the past, Rzeppa was devastated when he learned of his condition. Doctors assured him that the melanoma had not spread — thanks to Mancuso’s message, doctors at Henry Ford Health System were able to find the cancer before it was too late. Rzeppa had the cancerous spot removed and, later, he underwent a skin graft.
Much to the surprise and delight of the family, Rzeppa had recovered from the procedures just in time for Frei’s wedding on April 28.
“[Rzeppa said he] wanted to look good and impress new family members,” Frei says of Rzeppa, who the family calls “Big Papa.” “Once he started to heal from the procedures, Big Papa got a new suit for the wedding and, with the help of multiple family members, he arrived in Charlotte, North Carolina, for my wedding, beaming from ear to ear.”
Photos from the ceremony showed Rzeppa smiling wide next to Frei and her husband, Billy, with a noticeable scar on his forehead.
“It meant the world to me to have my grandpa at my wedding. Him and I are good buddies and he has always been there for me, my siblings, and cousins,” she tells PEOPLE. “Our DJ at the wedding spoke to ‘Big Papa’ between the ceremony and reception and arranged a special dance for he and myself, that I will never forget.”