Case 276.

HistoryA 34-year-old man presented to the emergency department of our hospital for progressive shortness of breath and worsening productive cough of 2 weeks duration. He reported a 10-kg weight loss over 4 months but denied experiencing fever, chills, night sweats, or gastrointestinal, musculoskeletal, or neurologic symptoms. His medical history was unremarkable. Although he was a native of Morocco, he had lived in Europe for many years and worked as a truck driver. The patient had a smoking history but had quit smoking 5 years prior to presentation. He denied alcohol abuse or recreational drug use. He did not have any allergies. Besides bilateral clubbing, the physical examination findings were normal. At the time of admission, he had an oxygen (O) saturation of 87% at ambient air, which increased to 100% with 1 L of O administered via a nasal cannula. The blood sample revealed a slight increase in his hemoglobin concentration (18.7 g/dL; normal range, 13.6-17.2 g/dL) and hematocrit level (50.8%; normal range, 39%-49%). His inflammatory parameters were normal, as were his hepatic and renal function. The arterial blood gas test showed partially compensated pulmonary alkalosis (pH, 7.43; normal range, 7.35-7.42; PCO, 26 mmHg; normal range, 38-42 mmHg; PO, 89 mmHg; normal range, 75-100 mmHg; bicarbonate level, 17 mEq/L [17 mmol/L]; normal range 22-26 mEq/L [22-26 mmol/L]). The results of the pulmonary function tests were expressed as the percentage of predicted values and were 92% for forced vital capacity, 93% for forced expiratory volume in 1 second, 116% for total lung capacity, and 60% for diffusing capacity of carbon monoxide. Anteroposterior chest radiography and enhanced chest CT were also performed at admission (Figs 1-3).[Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text].