[A case of pericarotid syndrome with retention cyst in ethmoid sinus].

A 42-year-old man noted pain on the left side of his forehead and left ptosis. On examination, he showed conjunctival hyperemia, ptosis and miosis in the left side, as well as hyperesthesia in the first branch of left trigeminal nerve. An MRI of his brain showed a retension cyst in the left ethmoid sinus. There was neither abnormalities in the parasellar lesion nor in the neck. We diagnosed him with pericarotid syndrome rather than cluster headache or Raeder syndrome. Five cases who had paranasal sinus lesions as a cause of cluster headache or Raeder syndrome have been reported. More cases are needed to clarify the association of retension cyst in ethmoid sinus and pericarotid syndrome.