A 38-year-old man presented to the ED with fever, poor appetite,
and a cough productive of yellowish sputum.
Over the previous two weeks, the patient noted progressive weakness
and a 10-lb weight loss, worsening cough, and increasing fever and
chills. He did not have chest pain or shortness of breath and had
never previously been ill.
He smoked one pack of cigarettes per day and was formerly an
alcoholic, but had not had a drink in over a month since being enrolled
in a rehabilitation program. He had occasionally used cocaine in
the past but had never used drugs intravenously. He also denied
ever having had homosexual contacts. A tuberculin skin test two
years earlier was positive, but he was not treated for this. He
worked for a private refuse collecting company and, aside from a
trip to North Carolina two years earlier, had not traveled outside
the New York metropolitan area. He had had no contact with wild
or ill animals.
On examination, he was a slim young
man in no acute distress. His vital signs were normal aside from
a rectal temperature of 101.7°F. His oxygen saturation
was 97% on room air. There were several nontender 1-cm
lymph nodes in both axillae and inguinal regions. His lungs were
clear and abdomen was nontender, without hepatosplenomegaly.
His white blood cell count was 6,000/mm3, hematocrit
27.8% (MCV 88 μm3) and platelet
count 220,000/mm3. Two hours after his arrival
in the ED, his temperature rose to 104°F.
His chest radiographs are shown in Figure 1.
- What are the potential diagnoses in
In this patient’s PA radiograph, you can compare an
abnormal hilum on the left with a relatively normal hilum on the
right (Figure 1). The hilum is often an area of difficulty in chest
radiograph interpretation. Simply observing whether the hilum looks “big” is
not a reliable means of determining whether it is normal or abnormal.
Instead, accurate interpretation depends on an understanding of
the normal anatomical features of the hilum and the changes that
occur in various disease states.
The hila are composed of pulmonary arteries and veins, major
bronchi, and lymph nodes. Normally, the pulmonary
arteries make up most of the radiographic density of the hila
(Figure 2). The superior pulmonary veins make
a smaller contribution to hilar density, whereas the inferior pulmonary veins enter the left
atrium inferior to the hilum and make no contribution to hilar density.
The pulmonary arteries (light gray)
make up most ...