The unidentified patient was receiving treatment in the Intensive Care Unit at the University of California San Francisco Medical Center, according to a November 29 article in the New England Journal of Medicine.
The patient, who had a history of heart problems, had been placed on oxygen and given blood thinners to help circulate blood and prevent clogging.
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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.
When Wieselthaler and his team delicately spread out the clot, they discovered "that the architecture of the airways had been retained so perfectly that they were able to identify it as the right bronchial tree based exclusively on the number of branches and their alignment". 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.
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.
A man being treated in hospital for heart failure at 36 died after coughing up part of his lung.
The woman suffered from asthma, and and after two weeks of particularly harsh coughing, herniating her lung so it slipped through her ribs.