What's the Connection?

A CLINICAL PROBLEM-SOLVING article by Aharon Sareli from University of Pennsylvania, Philadelphia.
A 26-year-old man presented with 1-month history of persistent cough productive of white sputum, which was occasionally tinged with blood. He reported mild pleuritic chest pain. His cough had been treated with azithromycin with no resolution of his symptoms.
Five years before this presentation, the patient had been treated for a right-sided spontaneous pneumothorax. Three years before presentation, he was found to have a spontaneous left renal-artery dissection with renal infarction.
On present examination, the patient appeared comfortable and was in no acute distress. He had generalized joint hypermobility involving both small and large joints.
A chest radiograph revealed a left lower-lobe cavity with an air–liquid level, small left-sided apical pneumothorax, and left hydrothorax. Chest CT revealed subcentimeter nodules with surrounding haziness.
The patient received 14 days of intravenous ampicillin–sulbactam to treat a presumed lung abscess. Seventeen weeks later, the patient presented with massive hemoptysis.
In this case, both the discussant and the clinical team did what experienced diagnosticians often do when confronted with a patient whose illness does not lend itself to a simple diagnosis: try to find the connection between the present illness and past abnormalities.