L:\usmle review 7 - Sinoe medical homepage.

Centriacinar emphysema (choice A) is characterized by enlargement of the central portions of
the acinus, i.e., the respiratory bronchiole, and its pathogenesis is related to exposure to tobacco
products and coal dust.
Interstitial emphysema (choice C) is not a true form of emphysema. It results from penetration of
air into the pulmonary interstitium. This may occur when alveolar tears develop because of a
combination of coughing and airway obstruction (e.g., children with whooping cough) or a chest
wound that injures the underlying lung parenchyma (e.g., a fractured rib).
Compensatory emphysema (choice B) and paraseptal emphysema (choice E) are associated
with scarring. Both are frequent but usually clinically silent. Paraseptal emphysema, however,
may lead to spontaneous pneumothorax in young patients. In fact, this form is more severe in
areas adjacent to the pleura, where large, cyst-like structures may develop and rupture into the
pleural cavity.
A 57-year-old woman with a history of hypertension and arthritis is referred to a rheumatologist
for evaluation. A complete blood count (CBC) is normal, and a mini-chem panel shows no
electrolyte abnormalities. Her erythrocyte sedimentation rate (ESR) is elevated, and an
antinuclear antibody test (ANA) is positive. Further antibody studies are performed, and the
results are shown below.
Anti-histones
Anti-double stranded DNA
Anti-single stranded DNA
Anti-SSA
Anti-SSB
Anti-SCI-70
Anti-Smith
Anti-centromere
Anti-RNP
high titer
not detected
not detected
not detected
not detected
not detected
not detected
not detected
not detected
Which of the following diseases is suggested by these results