French doctors were taken aback when they discovered the reason for a patient’s sore, swollen belly: He had swallowed around 350 coins — $650 worth — along with assorted necklaces and needles.

The 62-year-old man came to the emergency room of Cholet General Hospital in western France in 2002. He had a history of major psychiatric illness, was suffering from stomach pain, and could not eat or move his bowels.

His family warned doctors that he sometimes swallowed coins, and a few had been removed from his stomach in past hospital visits.

Still, doctors were awed when they took an X-ray. They discovered an enormous opaque mass in his stomach that turned out to weigh 12 pounds — as much as some bowling balls. It was so heavy it had forced his stomach down between his hips.

Five days after his arrival, doctors cut him open and removed his badly damaged stomach with its contents. He died 12 days later from complications.

A decade of swallowing coins

One of his doctors, intensive care specialist Dr. Bruno Francois, said the patient had swallowed the coins — both French currency and later euros — over about a decade. His family tried to keep coins and jewelry away from him.

“When he was invited and came in some homes, he liked to steal coins and eat them,” Francois said.

The case history of the French patient, whose name was withheld, was reported in Thursday’s New England Journal of Medicine.

The patient’s rare condition is called pica, a compulsion to eat things not normally consumed as food. Its name comes from the Latin word for magpie, a bird thought to eat just about anything.

What is pica?

Pica can take the form of eating dirt, ashes, chalk, hair, soap, toothbrushes, burned matches and many other things. Francois once treated a patient who ate forks. Most such objects are small enough to pass on their own, but some must be removed by doctors.

The condition is perhaps best known in children and pregnant women but is also sometimes linked to psychiatric illness.

A few details of the Frenchman’s case were presented Jan. 1 along with the X-ray — but no explanation of the stomach mass — as a challenge to New England Journal of Medicine readers in a fixture called “A Medical Mystery.”

Dr. Lindsey Baden, an editor at the journal, reported that 666 readers in 73 countries — mostly doctors or doctors-in-training — contacted the journal to try to solve the mystery. Almost 90 percent settled on diagnoses consistent with pica, but only 8 percent correctly identified coins.

“This case serves as a reminder of important factors that should be considered in the care of patients who are mentally impaired,” Baden wrote.