en Skull Base Case report <div style="text-align: justify;"><strong>Background and Importance: </strong>Arachnoid cysts are benign nontumoral lesions that are usually found incidentally in brain imaging. Suprasellar Arachnoid Cysts (SSACs) are rare. They can cause hydrocephalus and increased intracranial pressure, lower cranial nerve impairment and endocrine disorder. Sometimes arachnoid cysts become complicated by subdural hematoma/hygroma.&nbsp;<br> <strong>Case Presentation:</strong> We describe a patient with a suprasellar arachnoid cyst that was complicated with symptomatic subdural effusion and increased intracranial pressure after minor trauma.<br> <strong>Conclusion: </strong>Although these cysts are rarely complicated with subdural hematoma/hygroma, and intracystic hemorrhage, the probability of subsequent subdural hygroma and increased intracranial pressure should not be underestimated.</div> Subdural effusion, Suprasellar arachnoid cyst 115 118 http://irjns.org/browse.php?a_code=A-10-189-1&slc_lang=en&sid=1 Omidvar Rezaei rozgarnana@gmail.com 10031947532846002267 10031947532846002267 No Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Karim Moradian-Kokhdan srazme82@gmail.com 10031947532846002268 10031947532846002268 Yes Department of Neurosurgery, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran Saeed Razmeh norodiasht@gmail.com 10031947532846002269 10031947532846002269 No Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Kaveh Ebrahimzadeh kavehebrahimzadeh@gmail.com 10031947532846002270 10031947532846002270 No Department of Neurology, Faculty of Medicine, Yasuj University of Medical Sciences, Kohgiluyeh and Boyer-Ahmad, Iran Guive Sharifi narenjijome@gmail.com 10031947532846002271 10031947532846002271 No Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Samadian mdsamadian@hotmail.com 10031947532846002272 10031947532846002272 No Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran