Pituitary apoplexy after hypo-fractionated stereotactic radiotherapy

Abstract

Introduction : Pituitary apoplexy is a rare phenomenon in pituitary adenomas. We present a case of pituitary apoplexy that developed shortly after hypo-fractionated stereotactic radiotherapy (HF-SRT) for a pituitary adenoma. To our knowledge there is no prior report of pituitary apoplexy following stereotactic radiotherapy. Case Report : A 67 year old female initially presented with visual abnormalities. Workup then revealed a large sellar mass. She underwent a trans-sphenoidal resection then with pathology demonstrating a non-secretory pituitary adenoma. Her vision returned to normal after the resection. Five years later, follow-up MRI showed evidence of recurrence. The size of the lesion and its proximity to the optic apparatus were not considered adequate for a single fraction stereotactic radiosurgery (SRS). Based on this, HF-SRT was recommended as an alternative to re-operation. The tumor was treated to a dose of 4,000 cGy given at 400 cGy per fraction. Two months later, the patient presented with visual impairment and ocular palsies. She was diagnosed to have pituitary apoplexy. Although spontaneous tumor apoplexy cannot be excluded, a causal role for radiotherapy is hypothesized. Conclusion : Radiotherapy as a cause of pituitary apoplexy is not well understood or documented. Pituitary apoplexy should be suspected in a patient who develops new onset headaches and visual disturbance during or shortly after radiotherapy. Rapid diagnosis of pituitary apoplexy allows for aggressive management and neurosurgical decompression which decreases mortality and morbidity.