An astounding medical occurrence was shared by American doctors earlier this week to their 546,000 twitter followers.
The New England Journal of Medicine (NEJM) posted a picture on Twitter of a coughed up blood clot in the shape of a patient's right lung's bronchial tree.
The post was medically detailed.
"A 36-year-old man was admitted to the ICU with an acute exacerbation of chronic heart failure. After a ventricular assist device was placed and anticoagulation therapy initiated, haemoptysis developed, and he expectorated a cast of the right bronchial tree," the journal wrote.
The 36-year-old patient had been had been coughing up tiny blot clots for days and after an extreme coughing spell, this "very, very, very rare" clot emerged.
The pulmonary surgeon Dr Georg Wieselthaler told The Atlantic when he carefully spread out the clot, realising it was the perfect shape, he was "astonished".
"It's a curiosity you can't imagine."
Doctors aren't quite sure how the clot stayed intact while being coughed up, but Dr Wieselthaler suspects it could be due to the patient's higher level of fibringen in his blood, which acts like a glue.
Sadly, the patient died a week later from complications of heart failure.