H1N1 pneumonia

Case contributed by Mostafa El-Feky



Patient Data

Age: 55 years
Gender: Male

At presentation


Diffuse scattered ground glass opacities at both lung lobes, mainly in subpleural distribution, more affecting both lower lobes with the right lower lobe most affected showing air space consolidation.

Mild right pleural effusion.

The heart is mildly enlarged with mild pericardial effusion.

Overview of the upper abdomen revealed:

  • cirrhotic liver
  • mild splenomegaly
  • enlarged both kidneys with the morphology of autosomal dominant polycystic kidney disease, showing multiple bilateral hyperdense cysts

After 5 days


Currently, more extensive involvement with the reversal of pulmonary patches predominance with current predominance on both upper lobes. Patches are more widespread and confluent at the right lower lobe subpleural region, suggestive of acute interstitial pneumonia

Mild bilateral pleural effusion.

Mild pericardial effusion.

Overview of the upper abdomen revealed denovo moderate free ascites.

Throat swab


Throat swap revealed positive for H1N1 PCR test.

Case Discussion

The diffuse confluent ground glass patches suggest acute interstitial pneumonitis, which histologically may reflect diffuse alveolar damage (DAD)Ground-glass attenuation is the most common pattern of H1N1 pneumonia as one of viral pneumonia. This case also shows confluent consolidation with a peripheral subpleural location involving the right lower lobe and associated pleural effusion. 

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