Suprasellar Arachnoid Cyst with Spontaneous Intracystic Hemorrhage: A Rare Complication – Role of MR and Illustration of a Case

BACKGROUND: Arachnoid cysts are congenital or developmental intra-arachnoidal CSF-filled lesions, which develop probably as a result of splitting or duplication of the arachnoid membrane. Most of them are asymptomatic and are detected as incidental findings on Computed Tomography or Magnetic Resonance Imaging of the head carried out for other reasons. Although complications such as intracystic, subdural, and extradural hematomas are well known after a trauma, spontaneous hemorrhage in an arachnoid cyst is a rare and serious complication with atypical imaging features on cross-sectional imaging and only less than ten cases are documented in the literature till date, with none of them in the suprasellar location. CASE REPORT: A 40-year-old female patient presented with history of headache since two months, which was sudden in onset, holocranial. CONCLUSIONS: Spontaneous intracystic hemorrhage is an uncommon and serious complication of arachnoid cysts, which can give rise to atypical features on imaging. Therefore familiarity with this rare complication is indeed essential.