Endocrine Abstracts

A 32-year-old man was urgently referred to the endocrinology and neurosurgical teams by the neuro-ophthalmologist. He gave a 3 week history of sudden onset of left-sided visual impairment, with further visual deterioration a week previously. Urgent review in the eye clinic had revealed that the visual acuity in his left eye was reduced to finger counting only, with a pale left optic disc and a relative afferent pupillary defect on examination. Visual field testing demonstrated a temporal hemianopia in the right eye, with residual vision only in the upper nasal quadrant in the left eye. He reported a left-sided headache and some nausea at the time of onset of the acute visual loss. He had experienced intermittent headaches and reduced libido over the previous 1-2 years, with lethargy and occasional non-specific visual symptoms over previous months. An urgent MRI brain revealed a 38x30x27mm pituitary mass extending into the suprasellar cistern, with stretching of the optic chiasm and compression of the left side. There was evidence of haemorrhage within the lesion. His pituitary profile showed:- prolactin 16,341 (normal <324) mU/l, LH 3.1 IU/l, FSH 3.7 IU/l, testosterone 6.7 (normal 7.6-31) nmol/l, IGF-1 35 (normal 11-29) nmol/l, random cortisol 233 nmol/l, TSH 1.31mU/l, FT4 11 (normal 11-23) pmol/l. A diagnosis of pituitary apoplexy within a macroprolactinoma was made. The patient underwent urgent transsphenoidal surgery following pituitary MDT discussion in an attempt to improve/preserve his vision. He was also started on cabergoline. He reported a rapid and significant visual improvement post-operatively. He has been advised to continue on cabergoline.

Discussion: 1. First line treatment for a macroprolactinoma is dopamine agonist therapy. In our case, surgery was offered in view of the acute visual deterioration, felt most likely be secondary to pituitary apoplexy causing a sudden enlargement of the pituitary lesion. The good post-operative visual outcome supported the presence of neuropraxia to his optic nerve from apoplexy. 2. This case highlighted the importance of detailed discussion of the benefits and risks of management options both within the pituitary MDT and with the patient. Urgent surgery was offered to improve/preserve vision, although this outcome could not be guaranteed. Hypopituitarism was a risk; he had no children, and future fertility could be affected.