A 33 year old primip presented to the local ophthalmic hospital at 34+4 weeks gestation with two weeks of blurred vision. Examination revealed a bitemporal hemianopia and reduced visual acuity. She was previously fit and well, and a pre-eclampsia screen was negative. An MRI scan demonstrated a haemorrhagic pituitary lesion extending into the suprasellar cistern with mild compression of the optic chiasm. Pituitary function tests showed a raised prolactin 3844 mU/l, isolated hypothyroxinaemia (TSH 2.16 miU/l, fT4 8.4 pmol/l), evening cortisol of 264 nmol/l, LH 0.2 iU/l, FSH <0.1 iU/l and oestradiol 63 676 pmol/l. She was commenced on cabergoline 500 mcg after discussion between the endocrine and neurosurgical teams in an immediate medical attempt to relieve pressure on the optic chiasm. In view of her low T4 she commenced thyroxine 50 mcg and prednisolone 5 mg for safety. However, after 10 days of cabergoline treatment, despite a reduction in prolactin to 1140 mU/l, a significant quadrantanopia and acuity defect remained. With the need for neurosurgery increasing, and after discussion with the obstetric team, she underwent induction of labour. She had a successful vaginal delivery at 36+2 weeks gestation. As the bitemporal quadrantanopia persisted postpartum (with continued elevation of prolactin at 1232 mU/l), she underwent stereotactic endoscopic transphenoidal hypophysectomy 6 days post-partum. This completely resolved her visual field and acuity defect. Five days post-operatively her prolactin was 191 mU/l, 0900 h cortisol 230 nmol/l, TSH 0.54 iU/l and fT4 16.6 pmol/l. She was therefore weaned off thyroxine and cortisol. Histology demonstrated a sparsely granulated lactotroph staining adenoma with Ki67 of 2%. This case demonstrates the multidisciplinary challenges in the management of pituitary lesions in pregnancy. Clinical acumen is essential, as well as cautious interpretation of pituitary hormone levels in the absence of robust, trimester-specific reference ranges for pituitary hormones. Decisions require consideration of the risks and benefits to both mother and fetus, and demand an effective multidisciplinary approach.
11 Nov 2019 - 13 Nov 2019