THE CASE: A 77-year-old woman who has had shortness of breath and intermittent left flank pain for the past 2 to 3 days is brought by her family for evaluation. The dyspnea worsens when she lies down. She denies chest pain, back pain, and syncope. She has also had mild nonbloody diarrhea of 2 days’ duration but no vomiting or oral intake intolerance.
