Pituitary apoplexy presenting atypical time course of ophthalmic symptoms.

Pituitary apoplexy is defined as a sudden loss of blood supply to the pituitary gland, leading to tissue necrosis and hemorrhage. Its clinical symptoms are characterized by sudden onset of headache, nausea, vomiting, ophthalmic symptoms and hormonal dysfunction. A 65-year-old woman presented with left-sided ptosis and blurred vision. These ophthalmic symptoms gradually worsened for one month without headache, visual acuity and field deficit. Neuro-ophthalmic examination revealed left oculomotor nerve palsy. Magnetic resonance imaging (MRI) revealed a round mass lesion in the left cavernous sinus, which was initially suspected as thrombosed cerebral aneurysm or hemorrhagic Rathke's cleft cyst. The mass lesion was finally diagnosed as pituitary apoplexy. The patient underwent trans-sphenoidal surgery and oculomotor nerve palsy improved after the surgery. Early diagnosis and treatment including surgical decompression are crucially important in patients with oculomotor nerve palsy in pituitary apoplexy, but the symptoms of pituitary apoplexy may slowly progress. It should be noted that pituitary apoplexy could be misdiagnosed as cerebral aneurysm or Rathke's cleft cyst.