Necrotizing brainstem leukoencephalopathy six weeks following radiotherapy.

A 71-year-old male with a null cell pituitary macroadenoma was given peripituitary region radiotherapy (4,346 Gy units) over a 1-month-period and 6 weeks later developed the rapid onset of blurred vision, diplopia, ataxia, incoordination, cranial nerve palsy, somnolence, and respiratory distress. His fixed neurologic deficits required ventilatory support, feeding tube placement, and chronic hospitalization until his death 1 year later. At autopsy, necrotic foci with dystrophic axonal calcification were found throughout the brainstem, associated with mild focal vascular hyalinization but without fibrinoid necrosis, telangiectasias or large vessel abnormalities. This unusual case of fatal "early delayed" radiation injury is compared to previous literature cases.