Pulmonary infarct

Pulmonary infarct
Diagnosis in short
Pulmonary infarct. H&E stain.
Synonyms	lung infarct
LM	necrosis of alveolar walls - loss of nuclei, alveolar hemorrhage, +/-evidence of underlying cause
LM DDx	see Associated Dx
Gross	lung periphery, classically described as wedge-shaped
Site	lung
Associated Dx	underlying causes: sickle cell disease, pulmonary embolism, vasculitides, malignancy (e.g. lymphoma), drug toxicity, others
Prevalence	uncommon
Radiology	reverse halo sign
Prognosis	dependent on underlying cause
Treatment	dependent on underlying cause

Pulmonary infarct is the death of lung tissue due to oxygen deprivation.

It is also known as a lung infarct, lung infarction, and pulmonary infarction.

General

• Uncommon because of the dual blood supply (systemic via the bronchial arteries, pulmonary via the pulmonary arteries).

Common causes:

• Pulmonary embolism.
• Sickle cell disease.

Less common causes:

• Lymphoma, esp. acute promyelocytic leukemia.
• Drugs, e.g. chemotherapy.
• Vasculitis.
• Others.

Gross

• Lung periphery, classically described as wedge-shaped.

Note:

• In a histologic section, the classic wedge-shaped infarct is triangular:
  • Base of triangle on the pleural aspect.
  • Point furthest from the pleura close to the compromised artery that lead to infarction.

Radiology:

• Reverse halo sign.

Images:

• Pulmonary infarct (sciencephoto.com).
• Pulmonary infarct (flickr.com)

Microscopic

Features:

• Necrosis of alveolar walls - loss of nuclei.
• Alveolar hemorrhage.

Image

• 

  Pulmonary infarct - low mag. (WC)

See also

• Pulmonary pathology.
• Infarct.