Chronic expanding pituitary hematoma without rebleeding after pituitary apoplexy

BACKGROUND: Enlargement of intracerebral hematoma without rebleeding in chronic phase is a rare but well-known clinical condition, and is well-described as chronic expanding intracerebral hematoma. However, chronic enlargement of pituitary hematoma without rebleeding after pituitary apoplexy is extremely rare. CASE DESCRIPTION: We report a case of chronic expanding pituitary hematoma without rebleeding after pituitary apoplexy. A 29-year-old male presented with sudden onset of headache and vomiting. Magnetic resonance imaging (MRI) demonstrated a pituitary mass lesion with hematoma, consistent with pituitary apoplexy. Neuro-ophthalmological examination revealed no visual field defect, and endocrinological evaluations showed an elevated prolactin level. Pituitary apoplexy due to a prolactinoma was the most likely diagnosis. He was conservatively treated because he exhibited no visual disturbance. Three weeks after the onset, he gradually began to complain of blurred vision and neuro-ophthalamological examination revealed bitemporal upper quadrant hemianopsia. MRI showed enlargement of the pituitary hematoma without any finding suggestive of rebleeding. This enlarged mass lesion compressed the chiasm. The patient was operated on via transsphenoidal approach. After dural opening, xanthochromic fluid spouted out, but no fresh clot could be detected within the cyst. After the operation, the visual field disturbance resolved completely. The possible mechanism of hematoma enlargement is considered to be expansion due to the serum exudation from capillaries of the hematoma capsule. This pathogenetic mechanism is common in enlargement of chronic subdural hematoma. CONCLUSIONS: This case is the first report of chronic expanding pituitary hematoma without rebleeding after pituitary apoplexy.