As a child, Josh Patner became accustomed to stepping over his mom, who used to lie down in the kitchen whenever her mother-in-law would call. “My grandmother would talk her ear off,” Mr. Patner,...

In March 1961, Dr. Anthony Epstein, a pathologist at Middlesex Hospital in London, almost skipped a visiting physician’s afternoon lecture about children with exceptionally large facial tumors in Uganda. The physician, Dr. Denis Burkitt,...