Case 97. Dirofilariasis of lung (44 y-o F)
         
   
Surgical specimen of an asymptomatic coin lesion with peripheral eosinophilia
   
         
   
Key words : Dirofilaria immitis, visceral larva migrans, coin lesion
   
         
   
zoonosis
   
     
 
     
A coin lesion is seen in the subpleural region of the right middle lobe (CT scan).   A thrombosed pulmonary artery branch is observed in the center of the encapsulated and necrotic coin lesion (HE, low power).
     
 
     
A cut surface of a helminth is noted in the embolus of the pulmonary artery (elastica van Gieson).   The necrotic microfilaria of Dirofilaria immitis is histologically featured by the internal ridges of the thick cuticle, a well-developed muscle layer and small-sized gut (HE, high power).