Endocrine Abstracts

Introduction: Intrasellar arachnoid cysts are rare and clinically resemble nonfunctional pituitary adenomas. Arachnoid cysts should be considered in the differential diagnosis of cysts developing in the sellar region, together with cystic pituitary adenoma, craniopharyngioma, epidermoid cysts, and Rathke’s cleft cysts. Symptomatic cysts are operated but can recurr.

Case presentation: We present 2 cases of compressive intrasellar arachnoid cysts occurring in elderly patients who presented with severe loss of vision.

Case 1: A 75-year-old woman presented with bitemporal hemianopsia and recurrent falls without loss of consciousness. Cerebral MRI showed a sellar and suprasellar cystic lesion measuring 25/23/20mm, compressing the pituitary gland and the optic chiasm. Endocrine assessment was not performed. The patient underwent cyst resection and fenestration by transcranial microsurgery, with marked improvement of vision and visual fields. Pathology confirmed an arachnoid cyst. 9 months post-surgery, vision and visual fields deteriorated and a cyst recurrence was diagnosed on MRI. Repeat surgery resulted in visual improvement. The patient presented in our service 8 months after the second surgery with dizziness and severe asthenia. Hormonal tests revealed p nhypopituitarism and disconnection hyperprolactinemia (56.25 ng/mL). Hydrocortisone and L- thyroxine replacement were given. Visual fields were again affected, but subjective vision was good and the patient active and independent and the pituitary MDT recommended active monitoring of visual function and MRI.

Case 2: An 85-year-old woman with a history of tachycardia-bradicardia syndrome, an implanted pacemaker, aortic stenosis and heart failure, presented with longstanding (2 yrs) severe visual impairment “I see only half of people” and physical asthenia. Computerized visual field testing revealed findings atypical for the optic chiasm compression: right eye temporal hemianopsia and superior nasal quadrantanopsia and left eye paracentral visual field defect with superior nasal quadrantanopsia. A pituitary CT scan showed an enlarged sella turcica with fluid density, compressing the pituitary gland and optic chiasm. Laboratory tests demonstrated gonadotroph insufficiency and moderate hyperprolactinemia, without corticotroph and thyrotroph insufficiency. The patient and her family were against surgery. Pituitary MDT recommended close monitoring. We are trying to arrange an MRI scan, taking the pacemaker into account.

Conclusion: Intrasellar arachnoid cysts can affect pituitary function and visual function, requiring surgery. We describe two severely symptomatic cases, one with recurrence following repeat surgery and one with a patient refusal of surgery. Pituitary function should be assessed by hormonal tests pre- and post-operatively and replacement should be prescribed as needed.