He had been experiencing a litany of symptoms his doctors couldn’t explain: lumps that kept appearing and disappearing, blinding pain in his eyes that lasted for a day and came back another, a small muscle in his forehead that he felt “snap.” His white blood cells soared, and itchy rashes covered parts of his body. His joints ached. He was constantly hungry and he had been eating a lot, but he couldn’t gain weight. There was a sinking feeling that his body had become host to unwelcome visitors, but tests showed nothing. One morning, he noticed a faint yellowish lump...