UMEM Educational Pearls

Category: Visual Diagnosis

Title: What's the Daignosis?

Posted: 7/25/2011 by Haney Mallemat, MD (Updated: 8/28/2014)
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34 y.o. male with history of IVDA (intravenous drug abuse) complains of fever, chills and cough. Diagnosis?


Answer: Lung Abscess (from septic pulmonary emboli)

Lung Abscess

  • Necrosis of lung parenchyma with pus and debris-filled cavities

  • Caused by direct injury (e.g., aspiration pneumonia) or secondary causes (e.g., tricuspid  endocarditis, bacteremia, etc.)

  • Suspect with:

    • Loss of airway reflexes (e.g., CVA, seizures, alcohol / narcotic abuse, etc)

    • Poor dentition

    • Immunosuppression

    • IVDA

  • Gram positives, negatives and anaerobic bacteria have all been implicated.

  • CXR may suggest diagnosis, but CT scan better identifies abscess, necrotic tissue, empyema, or other pathology (see image below).

  • After drawing blood cultures, broad-spectrum antibiotics should be started and narrowed once culture data is available; address underlying cause (e.g., valve replacement for endocarditis).

  • Prognosis is generally good with normal immune function and antibiotics, but mortality sharply increases with immunocompromise and treatment delay.


Mansharamani N, et al. Lung abscess in adults: clinical comparison of immunocompromised to non-immunocompromised patients. Respiratory Medicine. Mar 2002;96(3):178-85

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