A Thirty-Four-Year-Old Woman with Chronic Dyspnea and Pulmonary Interlobular Septal Thickening

globin was normal. Relevant basic metabolic panel results were: creatinine 1.36 mg/dl (baseline 1.3) and bicarbonate 35 mg/dl. Urinalysis was normal. Arterial blood gases (in the emergency department on the 50% Venturi Mask) revealed: pH 7.33, pCO 2 65, pO 2 74 and oxyhemoglobin 92%. Chest radiograph and computed tomography (CT) scan at presentation are shown in figure 1 . Two-dimensional echocardiogram revealed normal left ventricular size and systolic function, mild diastolic dysfunction and no significant valvular abnormalities. Subsequent radiographs of the lower limbs ( fig. 2 ) showed significant osteosclerosis of the tibia and fibula, with sparing of the epiphyses and less pronounced femoral involvement. The patient was admitted to the medical intensive care unit requiring intubation and mechanical ventilation in February 2010. Despite aggressive management of volume overload from the 3rd to the 16th of February 2010, the lung parenchyma abnormalities persisted. A pulmonary artery catheter showed a mean pulmonary pressure of 36 mm Hg, a pulmonary artery occlusion pressure of 15 mm Hg and a normal cardiac output. She subsequently underwent a surgical lung biopsy. What is your diagnosis? A 34-year-old woman presented to our emergency department with profound dyspnea, present even at rest, associated with orthopnea, lower extremity edema and weight gain. She had first noticed dyspnea on exertion 1 year previously. She had recently been prescribed supplemental oxygen via nasal cannula in December 2009. Her past medical history was complex and significant for: (1) recurrent pancreatitis; (2) a minimally functional left kidney secondary to chronic perinephric inflammation of unclear etiology; (3) visual loss with papilledema which required bilateral optic nerve sheath decompression in July 2008, and (4) and autoimmune hemolytic anemia following red blood cell transfusion. Upon presentation, her blood pressure was 152/84 mm Hg, with a heart rate of 60 beats/min. She was breathing at a rate of 28 breaths/min and her oxygen saturation was 80% on 4 liters/min of oxygen via nasal cannula. She was obese, had a right lower eyelid xanthelasma, and we were unable to assess for jugular vein distention. She had bibasilar rales on lung exam, a regular rate and rhythm without murmurs or gallops on heart exam, and a nontender abdomen without organomegaly. On her extremities, she had bilateral 2+ pitting edema without clubbing. Complete blood count revealed a white cell count of 13,000/mm 3 and a platelet count of 599,000/mm 3 . HemoReceived: December 4, 2012 Accepted after revision: January 21, 2013 Published online. May 4, 2013