In Istanbul's Chora Church, a fourteenth century mosaic depicts Christ healing a multitude. One person depicted has crutches, another is blind, another appears to have rickets.
The work also shows a sitting man with a bulge nearly the size of a basketball in his groin area. According to the doctor, this is likely a massive inguinal or scrotal hernia.
"This artist put a giant scrotum on the top of a church. This is pre-Puritan," said Heyne, interpreting the art as saying, "Jesus came to save everyone."
"I think this is remarkable: 'No shame: come out and you will be healed'," he said. "I think it is a remarkable testament to what the human body was back then."
The mosaic could be the first depiction of a hernia.
The art history of European Christianity shows diseases now associated only with the developing world.
Other artworks show signs of longstanding diseases like leprosy, while others trace the arrival of diseases new to Christian Europe. A 1496 sketch from Albrecht Dürer shows a man with syphilis, just four years after the disease is believed to have spread to Europe from the New World.
Some figures in famous paintings show signs of finger deformities suggesting rheumatoid arthritis, like the hands of the nude women in Peter Paul Rubens' 1639 painting The Three Graces.
Leonardo Da Vinci's Mona Lisa portrait shows the famous subject in great detail. The 25-year-old woman appears to show an accumulation of cholesterol under the skin in the hollow of her left eye. Her hand shows a fatty tissue tumor. She is known to have died at age 37.
Heyne took these conditions together and asked whether Mona Lisa died of a cardiovascular event.
As for master artist Michelangelo, his training in anatomy helped give deeper artistic significance to his work. For instance, his statue Night from 1531, depicting a bare-breasted woman personifying Night, and perhaps death, appears to show signs of a breast tumor.
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Heyne did criticize some interpretations of Michelangelo's Last Judgment. While some suggested the bulging of some figures' eyes was intended to represent disease, he said it rather simply represented astonishment at the arrival of the apocalypse.
Review of art also helps doctors understand how patients with particular diseases or health conditions were viewed throughout history.
There is the example of the seventeenth-century Spanish painter Diego Velazquez, who painted at least ten portraits of people with dwarfism. These show their "dignity and beauty," and don't depict them as "court buffoons," Heyne said, suggesting this is another role for Christianity in art.