The man was on blood thinning drugs to help prevent clots, the Atlantic noted, also pointing out that this treatment can make bleeding in some areas more common. During his treatment, though, he began hacking and coughing profusely. After previously coughing up other, smaller blood clots, the man let out a big one, and up came this folded-over clot in the exact shape of his right bronchial tree, one of the primary parts of the lung.
Georg Wieselthaler, a transplant and pulmonary surgeon at UCSF, told the Atlantic his team was easily able to identify the origin of the clot, it was so detailed.
"We were astonished," he said. "It's a curiosity you can't imagine — I mean, this is very, very, very rare."
Wieselthaler told the publication that it was the man's blood medication that made the clot rubbery and able to survive the trip out his airway instead of breaking up, since blood clots are typically hard plugs of blood.
Wieselthaler and two other doctors subsequently submitted a report about the "curiosity" to the New England Journal of Medicine on November 29.
"The right bronchial tree consists of three segmental branches in the upper lobe, two segmental branches in the middle lobe and five segmental branches in the lower lobe," the case report's authors wrote. "The patient's trachea was subsequently intubated, and flexible bronchoscopy revealed a small amount of blood in the basilar branches of the right lower lobe."
After this episode, he ceased coughing up blood, and his tubes were removed a couple days later. Sadly, however, the patient died about a week later due to further complications involving his heart.