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An Unusual Cause of Chest Pain

Reviewed By Clinical Problems Assembly

Submitted by

Laura J. Hinkle, M.D.


Department of Medicine

Indiana University School of Medicine

Indianapolis, IN

W. Graham Carlos, M.D.


Division of Pulmonary, Critical Care, Allergy, and Occupational Medicine

Indiana University School of Medicine

Indianapolis, IN

Gabriel T. Bosslet. M.D., M.A.

Assistant Professor of Clinical Medicine

Division of Pulmonary, Critical Care, Allergy, and Occupational Medicine

Indiana University School of Medicine

Indianapolis, IN

Submit your comments to the author(s).


A 42-year-old African American man presented to the Emergency Department complaining of worsening chest pain and indigestion over one week.  Initial workup included a chest x-ray, which demonstrated an opacity nearly filling the right hemithorax (Figure 1a, 1b).  He was admitted for further evaluation by pulmonary, oncology, and thoracic surgery specialists, determined to be stable, and discharged from the hospital with arrangements made to complete the remainder of his evaluation as an outpatient.  He returned several weeks later with ptosis, dysarthria, dysphagia, and generalized weakness.  A repeat chest radiograph was unchanged.  He was admitted for further diagnosis and treatment.  On the second hospital day he developed acute respiratory failure necessitating transfer to the intensive care unit, intubation, and initiation of mechanical ventilation.

The patient had no significant past medical history and did not take any medications or supplements.  He denied tobacco use, but reported using alcohol and marijuana regularly.  He had not traveled outside of the United States and his family history was negative for malignancies.  A complete review of systems was significant for a 20-pound, unintentional weight loss over the last year and increasing shortness of breath for the past week.

Physical Exam

On presentation to the Emergency Department, his vitals included: temperature of 98.6°F, heart rate of 125 beats per minute, respiratory rate of 18 breaths per minute, blood pressure of 130/78, and pulse oximetry on room air of 92%.   The patient was thin and in no apparent distress.  He appeared to struggle when attempting to swallow water.  Trachea was midline and there was no palpable lymphadenopathy.  There was bilateral ptosis.  Breath sounds were clear on the left and diminished with dullness to percussion on the right.   S1 and S2 heart sounds were normal. The remainder of the exam was unremarkable.


Initial laboratory workup included a BMP and CBC.  His white blood cell count was 13.9 k/mm3 with 85% neutrophils.  His basic metabolic panel was significant only for a chloride level of 95 mmol/L and a bicarbonate level of 38 mmol/L.  Arterial blood gas obtained on FiO2 of 100% prior to intubation was pH 7.26, PaCO2 of 86 mmHg, and PaO2 of 322 mmHg.


Figures 1a & 1b: PA and lateral chest x-ray.

Question 1

What is the pathophysiology that best explains this patient’s clinical presentation?


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