A 19-year-old minor league baseball pitcher from South America felt pain in his left shin while pitching and presented to the trainer right after the game. He had suffered no injury to the shin, but over a period of 6 weeks, the pain became progressively worse. He had considerable nocturnal discomfort, but no fevers or night sweats. Anti-inflammatories, rest, and ice did not reduce the pain. The patient was otherwise healthy, with no other symptoms or notable history.