A Woman in Her 60s With Lung Adenocarcinoma Presents With Copious Watery Sputum and Respiratory Failure.

CASE PRESENTATION: A woman in her 60s presented with 1 month of progressive dyspnea, watery rhinorrhea, and paroxysmal cough productive of clear, watery sputum. She was diagnosed with epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma at another institution 1 week prior to presentation and 3 weeks after the onset of symptoms. She was a never-smoker. She denied fevers and had completed a course of antibiotics for presumed pneumonia, without clinical improvement. She presented to the hospital due to increasing severity of her shortness of breath.